Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caWhy Did I Buy This Crap? Room Acoustics BasicsJohn Heisz - Speakers and Audio Projects2023-10-17 | Sound advice on room treatment: youtube.com/@AcousticsInsider The basics of room acoustics are simple - use lots of thick absorbers to reduce the reverb time in the room. Of course you don't have to start off with a lot, but keep adding as you can afford it until you've reached a point where they are working effectively. But don't fall into thinking that you can get away with using more thinner panels - they need to be a minimum of 6" (150mm) thick, otherwise you are wasting space and money. And you are also killing too much of the high frequencies that you need to preserve to make a room that sounds good.
The key with thick absorbers is that they start working right away in the right way. They help to fix the problems that every small room has, and that's room modes and excess energy in the room. They are the easiest, the least complex and generally the most effective way to treat a room. While there are other effective methods, like Helmholtz and diaphragmatic, they are harder to design, build and put in a place where they'll work best. There are also electronic bass traps, but they are quite expensive and may not be more effective than standard absorbers.
So on to the idea of cancelling room modes by timing a signal to do that. I used the ringing bell as an example, but stopping that from continuing to ring would be trivially easy compared to doing that with an enclosed volume of air inside a room. And assuming you could do it and have it work as it needs to, you'd be unable to change anything in the room or it would stop working. That includes adding more people to the room or leaving the door open - it would throw off that delicate balance.
And like I said in the video, to stop the ringing you need to make a sound that's not part of the original signal to do that, and that's distortion. Any change to the original signal is, by definition, distortion. The best, proven method is with the brute force absorption I talked about. Room acoustics have been studied for hundreds of years and in the last 100 every possible method has been looked at in detail and tried. That doesn't rule out further discoveries in the future, but they would have to be much more sophisticated than the method described above.
Worth mentioning that I didn't mention diffusers. Those are only used after you've put in as much bass absorption as you possibly can. Diffusers only work on higher frequencies and have no impact of the bass frequencies. Also my absorber charts show the flow resistivity as 10,000 for both the foam and the fiberglass / rockwool. This isn't accurate, but is "close enough" to show the glaring differences between the thicknesses. That was the point - making the panel thicker so they will be effective down low. The flow resistivity has an effect, but not as much as making the absorber thicker.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caHorn Design Experiment - Does Shape Really Matter?John Heisz - Speakers and Audio Projects2023-10-11 | How much does the shape affect the performance of a horn or waveguide? This video is made to answer that. Each of the four are exactly the same size and thickness, making all the horns the same depth. Changes in shape are to the flare from completely flat to fully rounded. As noted in the video, the flat one has a significantly larger hole at the throat, and that's the biggest difference between the samples. Best overall is the fully rounded, with the smoothest response and the most horn loading gain centered at around 2800Hz. BUT, and this is important, "best" in this instance probably won't translate to audibly better for most serious listeners. Younger people who still have the capability to hear those high frequencies may hear a difference, but preference for sound quality is subjective, even though one measures objectively better. The response is virtually identical below 8KHz and there's not a lot of musical content above that in most songs. As the horn gets deeper the shape may have a more pronounced effect on the response, but the changes would have to be large to result in an easy to hear difference. One finding is that it seems a more important factor to avoid cancellations in the higher frequency (like that 13KHz null in the flat horn) is to make the throat as close to the tweeter dome as possible. This requires more tests, and I'll do that the next time I design a horn. Watch the video showing the horn I made for my speakers here: youtu.be/j6lG_EOiv8Y
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caSimple Trick to Make Speakers Sound like a Live Performance PLUS a Sound-Stage BlizzardJohn Heisz - Speakers and Audio Projects2023-09-14 | The simple trick is to be realistic about what's actually happening. The "sounds like the musicians are really here playing" standard for listening to a recording is too high of a bar to set for something that was never meant to reach it. That's not to say that your enjoyment of the recording can only be less than a live performance - not at all. I (for the most part) prefer listening to music in the comfort of my own home. My point is that these two things only seem the same on the surface. They are both music, but presented in a completely different way, and as a result don't stand up to a direct comparison. Like watching baseball on TV vs sitting in the stands at the stadium - same only on the surface. Or any other activity or event that can be experienced in radically different ways.
New music: Exquisite Corpse - Warpaint The Reminder - Feist Another Eternity - Purity Ring
In this video I tried to set up a test to determine that, but consider the results partly inconclusive. While I didn't hear a notable change in the sound stage and imaging, the speakers sounded different enough to cause a distraction. My impression is that if there is a change to the sound stage and imaging, it is very subtle and probably not something that could be used to consider when building (or buying) a new pair of speakers.
Also worth mentioning that I'm doing this in my acoustically treated listening room, and the results may differ if listening in the typical echo-chamber that most people listen in. My listening to compare the two conditions was several songs that I'm very familiar with, playing them with and without the extensions in place.
The recordings were done one channel at a time with the mic placed 1 meter from the speaker pointed at the area between the midrange and tweeter. I then combined both of those mono recordings into a single stereo track and that's what played in the video. One is without the baffle extensions and the other is with it, while the third is the original track used.
The music I used is from the YouTube audio library and has a fairly good amount of stereo separation to project a reasonable sound stage. However it's not a particularly well recorded and produced piece to begin with, but I can't spend hours looking for something better. I would love to use something better, but use of copyright material could cause problems, including having the video taken down.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caEQ with Crossovers? Really?John Heisz - Speakers and Audio Projects2023-09-06 | Bit of a system update and an excuse to talk about how I set up the crossovers for my active 4-ways plus subs. The usual way to design crossovers is to do a bunch of anechoic measurements and shoot for the flattest response possible. Then do some fine tuning by listening, however this is a step that some designers skip and just go with the measured response as "good enough". And that works for most rooms - flat response is the best all-round compromise.
But since these speakers will only be used in my listening room, I decided to design the crossovers tailored to that room - so the measurements I took were NOT anechoic. This allowed me to play with the crossover points and slopes (via the miniDSP 4x10) to not only separate the frequencies for the individual drivers, but also to "EQ" the response. I did this by changing the points and slopes so that I got the most even response that sounded the best to me.
For example the midwoofer cross to the midrange is at 910Hz for the midrange at 24db / octave, while the midwoofer crosses at 860Hz at 12db / octave. This flattened out a significant peak in the response around 900Hz that was there when I tried using matching points and slopes.
I won't lie - this took a LOT of time, both in changing the settings and in listening and measuring. But in the end I have a crossover configuration that sounds fantastic that I could then use to design the analog filters for the new active amplifier.
And I know this is beyond what most people can do, but I thought it would be interesting to show what's possible if your goal is the best sound quality you can get. This is a process that a lot of home theatre receivers try to approximate - room correction - but don't do very well because they are trying to correct a generically designed speaker to work in a room. My process is better because it designs the speaker to match the room without altering the original signal. As set up, I'm using no additional EQ at all. The unchanged original music goes straight through to the active amp.
I used a picture of a passive crossover for this video and you may think it's misleading. But the same thing can be done with passive crossovers in the same way as I did with active ones. In fact you might be able to use software like Xsim or VituixCad to design the crossovers after you measure the drivers individually in the room. That would eliminate the need for the miniDSP.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caDebunking Audio Truths - Cables Dont Make a Difference PLUS the Politics of AudioJohn Heisz - Speakers and Audio Projects2023-09-02 | To recap, all of the electronic components, which includes the cables used to connect them, are at the bottom of the list. The list I'm referring to is the list of factors that you can change that make the biggest difference in sound quality. This is about sound quality that you'll get listening in your room.
All competently made components will sound alike, and any differences will be too small to hear. This does not include equipment that has been "voiced" to sound a certain way, as in amps that have been designed to have more harmonic distortion or cables that intentionally degrade the signal. Both of these instances can result in SUBTLE differences, but do so by actually putting out a technically worse result. However, the ear likes what the ear likes, so "worse" in this instance can be a matter of taste and opinion. And remember that the ear is connected to a brain that interprets what it's getting and is therefore heavily influenced by what that brain wants to hear.
What really drives the truly subjectivity based audiophile to buy these products is the reputation of the products and the idea that in order to be in the club, you need to have it. The club I'm talking about is the one where all the coolest audiophiles hang out and brag about the gear they have and talk about how wonderful it sounds, and look down on anyone who isn't in the club. Of course this "club" isn't (usually) anything official, as in an organized association of members, but you know you are in if you buy the right things.
Next up is the recordings and they can range from terrible to amazing. Even though the quality of the recording is largely out of your control, you can decide to be selective and not listen to the ones that sound bad. Or, and this is what I do, you can try to ignore how bad they are because you love listening to them.
Speakers are where you'll find a lot of variability in how they can sound and the differences can range from subtle (for models in the same price range, typically) to very wide. Speakers that measure the "same" can sound much different, depending on a number of factors. For example I've always preferred the presentation of larger speakers to smaller ones, even when they mostly sound the same. To me, and I'm not completely ruling out a psychological influence, the larger speaker with larger drivers delivers the sound with more authority and presence. Presence being the "it feels more real" - note "feels", not "sounds". Other factors are how the low end is handled, whether the speaker is sealed or vented or dipole. This is why any attempt to judge the sound quality of speakers with measurements alone is a fool's game - you have to listen to them to really know how they sound.
Lastly at the very top of the list of factors that impact sound quality is the room you'll be listening in. And it's ironic that even today, it's the one factor that is ranked the least important to most audiophiles. In fact most completely ignore it (and that includes the lab coat objectivity based ones) and will go to great lengths to deny its significance. Instead they'll spend money on things from the bottom of the list thinking the greatest differences can be realized there.
The room is the biggest wild card because there is so much about it that can affect sound quality. From the size of the room to the shape and the makeup of the walls and what's in the room - all will have orders of magnitude more influence on sound quality than all of the electronics put together. And , also ironically, it's the one that you have the most control over, yet is almost universally ignored.
I spent nearly a full year treating my listening room and I can say without any doubt that the year spent was one of the best investments I've ever made. Since completion I've been using that room every single day. I spend all of my evenings there, from 5 in the afternoon until 10 at night, and sometimes longer. So I have that to compare - treated to untreated, unlike most audiophiles. They THINK they know what it's like, mainly because they heard (and look for) someone else say that it isn't needed or that it "ruins" the sound, being "too dead". I will say that a treated room is something you need to get used to, but when you do you'll never want to go back. I know I haven't.
And that isn't necessarily a bad thing, and it certainly wouldn't be if it was just agreed to in general terms and the industry was left go on it's merry way as it had been before these measurement ideals were introduced. But what has been happening, as is often the case with questionable ideas, people hear something in these ideas that appeals to them and they latch onto them. That appeal is always something that they like to hear - how they personally want it to be, and not typically for purely technical reasons.
The simple truth is that there are people (quite a lot, actually) who want to see everything controlled and regulated and rules set up that must be followed. And the idea of extending control (standards) into an area that previously had none is just the next cause for them to eagerly get behind. You know such people. You may be one. We've been indulging such people for far too long, now.
My view is that standards are ultimately destructive. On their face they seem like a way to improve a situation by taking away the variability you'd have without them, but in doing so they put real limits on growth and innovation. They take away the character and individuality we have when controls are not in place, and make everything the same. And when everything is the same, there are no real points of comparison. Take away the bad and can we really judge good? Take away the unique and can we truly judge art?
Art, you say! How does anything that is so science based (speakers) have anything to do with art?!? Well, whether you like it or not, listening to music for enjoyment is very much like studying a painting or sculpture, or any other variety of art. Unless, that is, you are only listening to judge the precision of the medium, like examining a painting to measure the different shades of green that were used, or the type of canvas it was painted on. Art appreciation is a subjective act, as is listening to music. You can't do it "wrong".
Is there a standard for art? If you look at what passes for modern art and compare that to what was happening 400 years ago, you'll quickly see there couldn't possibly be one. And while I'm certainly not a fan of most modern art, I appreciate the fact that it can exist because the artist was unencumbered from imposed standards and was free to produce it. And its existence gives me a point of comparison and makes me appreciate the art I do love even more.
But would it exist at all if everyone felt the same way as I do? The answer is obviously no, so that suggests that there are people who like (or even love) something that I find repugnant! How could that be? Again, it's entirely subjective!
Now here's the part that trips a lot of people up, especially the wide range of Sheldon Cooper types that we have in any technical field: recognizing that art and science can (and must) coexist. Even 10,000 years ago when primitive man was painting the walls in caves there was this art / science symbiosis. The paint itself is the science, while brushing it on the cave walls is the art. Without the art, the paint is useless. Likewise, without the science, the painter is out of a job (or pastime). But in the end it's not the utility of the paint that attracts us, but the art of the painter that used it.
So you could say that the paint is excellent from a technical point of view; much like a speaker can be excellent from a measurement point of view, but the paint needs to be used by the painter to produce the subjective art; much like the speaker is used to produce the entirely subjective sound quality. In the end you don't listen to the speakers, you listen to the music that's coming out of the speakers.
A pair of speakers that measures "perfectly" will sound different is different rooms to different people. And while the research conducted by Dr. Toole suggests that a less perfect speaker will sound bad to a lot of people, there will still be some that actually prefer how it sounds over the more "perfect" one. Reread the part above about modern art, if you have a problem understanding that.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caDebunking Audio Truths - Flat Response = Best SoundJohn Heisz - Speakers and Audio Projects2023-08-25 | Like I say in the video, please don't get worked up over the hype in the title and just go by what I'm saying in the video. I'm not really trying to "debunk" anything, just point out the very obvious connection between the speakers and the room they are playing in.
The frequency response measurements (includes off axis response) for speakers are done anechoic, meaning without room interaction. And that's a standard way to measure the objective performance of the speaker, but it's not tied to the reality of using that set of speakers in a room.
To measure THAT performance, you have to set them up in the room where they will be used, and that gives a true representation of what the actual sound quality is. You can not judge the sound quality of a pair of speakers based on the anechoic measurements - they have to be in the room they will be used in and you have to listen to them.
The room matters a great deal - as much as 50% of what you hear when a pair of speakers are playing is the room itself: the reflections and how the size / shape / density of the boundaries / and level of absorption change the sound you hear. I know it's easy to dismiss that effect (I used to) when you are not willing to do anything to change it. But denying reality doesn't mean it stops being a factor.
The experiment where you set up speakers in different rooms (and then outdoors) should illustrate quite clearly just how much of a factor the room is and the very real impact it has on the overall sound quality.
So buying speakers based on measurements and reviews of those measurements, is like buying food based on the ingredients without knowing if you like how it tastes. Music enjoyment is, like eating, a purely subjective act and while there are things about it that can be objectively measured, they would be the least significant factors in the process.
Add to that the fact that no one is making truly bad speakers these days and that means the anechoic measurements are even less relevant.
It's fine if you enjoy watching or reading reviews (either objective or subjective), but stop conflating that with determining how good a pair of speakers will sound in your room. For example, I enjoy watching camera reviews (for video and photography), but I never take just those reviews into consideration when buying a new camera. First thing I do is recognize that there's little actual difference in the objective performance between models where image quality is concerned, and it then comes down to features and ergonomics, and whether I can afford it.
If buying speakers without listening in the room you will use them, your main criteria for selecting a pair should be whether you can afford them and if they appeal to you visually. Because there's not going to be a significant difference between different models / brands in the same price range. And when you have them, you can then get to work setting them up in your room to optimize the sound quality you can get from them.
The best approach (and the one that has worked best for me) is to set up your speakers by ear, then do some basic in-room measurements and tweak from there. Tweaking means speaker positioning and EQ. To get the best sound you need to put in the time to do both.
AND if you really want the very best sound quality, you need to add effective room treatment that will reduce the strength and duration of the reflections that can dominate what you hear in a room. That means thick (at least 6" thick) acoustic panels placed where they will be the most effective.
Reducing the early reflections and the reverb time will dramatically boost clarity and detail, and you will hear the music like you've never heard it before. I can't over stress how much of an improvement effective room treatment will produce.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caProcess for Building a 10 Channel Amplifier - Assembly Details Part 3John Heisz - Speakers and Audio Projects2023-08-16 | To recap what's going on here, this amp has active crossovers that drive my 4-way active speakers. So for each speaker driver in the 4-way, there's an amp board and a crossover board. I designed the crossovers based on the setting I arrived at with my miniDSP setup - the DSP setup is what I was using before I made this new amp. DSP is digital and adjustable, while this new amp and crossovers are analog and fixed. I can only change the output level on each channel, not the crossover slopes or frequencies.
Getting all of the amp boards mounted on the heatsinks and wired to the power supplies and output banana jacks took the better part of a full day. A big part of that time was me testing each board before installing it to make sure they are working correctly.
Then more metal fab, I used some scrap aluminum extrusion to make the two decks that the crossover boards will sit on. I had a genius idea to bend tabs down to support the ends of the amp boards, but that failed when the tabs broke off. Worth a try, but I wish I'd tried on a scrap of the same aluminum before cutting the shelf. Then I had to cut the other shelf in the same way so it wouldn't look odd! And yes, I tried annealing the aluminum with a torch to make it softer - it didn't work.
With the first crossover board hooked up I can turn it on and see how much of a turn-on thump it creates. Not too bad, but I can eliminate it altogether by muting the inputs to the amp boards until the power supply for the crossovers stabilizes. Worked great and it only added one more full day to the build time!
The output of each crossover board stays disconnected from the amp boards for about two second after you switch the amp on, then the relays close and connect them. I used relays because I have a bunch of them that I got for next to nothing several years ago.
When you switch the amp off, the muting circuit detects the loss of AC voltage from the transformer and immediately turns the relays off, disconnecting them from the amps. That eliminates the sound that the crossover boards make as the power supply discharges.
With the crossover installed and the metal front panel screwed in place, I moved the amp down to my listening room to setup and use. It's not finished, but it's finished enough to use (or so I thought...) and I need to take a break from the project to do other things.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caMy Amp Blew Up!John Heisz - Speakers and Audio Projects2023-08-12 | A costly mistake and live and learn (they say, but who actually does that...?), however it was limited to just one amp board. Still, I had to tear it all apart and check everything to make sure there wasn't any collateral damage. That's the BIG downside of putting so much in one case - it literally took a full day to do that. With the blown board swapped for one of the "spare" channels, I got it up and running again. I'll eventually repair the amp board that blew and reinstall it, but like I said I don't really need it right now for anything important. The two new crossover boards are for the infinite baffle subwoofers that are in the front wall of my listening room. They are powered by a separate 4 channel amp that I built nearly two years ago and featured that build on this channel. While it isn't quite finished, it's finished enough to use every day until I find time to complete it. The crossover points for the sub boards are 15Hz high pass and 80Hz low pass. Both slopes are 4th order. I need to make another for the bass shaker I have in my chair, and that will use the 9th amp board in the case. I need to put the brakes on this new multichannel amp (name change, in case I blow any more boards...) for now, so I can get back to my real occupation - making woodworking videos on YouTube. I'll get the rest of it done when I get the time. My main channel: youtube.com/user/jpheisz Building my 4 channel subwoofer amp: youtu.be/UKhRA_GcmPI My infinite baffle subs: youtu.be/1hDV54c3tzA
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caAll I Can Say is... Wow!John Heisz - Speakers and Audio Projects2023-08-04 | The concept: use several midrange drivers ringed around a very efficient tweeter to create a high sensitivity point source. The mids / tweeter act like a dual concentric driver (coax) without the main problem that come from loading a tweeter into a moving horn - doppler distortion. I tried 4 mids to start (the first set of measurements) and found that the tweeter was still a good 8db more sensitive. I could pad it down, but decided to try adding two more mids and that raised the sensitivity of the mids by another 3db. The second set of measurements show the on and off axis response. The results are quite good and certainly better than I expected. With the crossover set to around 1400Hz, there's no significant amount of comb filtering. and the off-axis response is excellent. Of course this is just a very roughly done test to determine whether it's worth pursuing, and what I've seen so far pretty much guarantees that. The drivers I used are the Hi-Vi B3N 90mm fullrange and the Peerless BC25SC06-04 horn loaded tweeter. Both drivers are very low cost but my initial impressions are that they sound very good.
Is it worth doing? 6 of the B3N drivers cost less than a good quality midrange driver, but they require a much wider baffle to fit into. The most common thinking these days is that a wide baffle destroys imaging and soundstage, but I haven't found that to be a written in stone rule. I've made many different speakers of many different sizes and I can't positively say with certainty whether narrow speakers produce better a better defined soundstage. It's been my experience that speaker position plays a MUCH greater roll in how well a pair of speakers image. Also the room is a big factor, especially an excess of early reflections. And this is also at odds with the standard thinking on this today, with most saying you NEED the early reflections to produce a good soundstage. Since there are 6 midranges to install, the build is more complex. But I think that's offset at least a little bit by how interesting it looks. Looks count! I'll admit that I'm disappointed that I'm not getting a higher db output from 6 of these drivers (at the same power, each additional driver should add 3db). I thought that 4 would have come closer to the 96db output of the tweeter than they did. Some of that is from the mids operating on an open baffle and the efficiency should increase when they are enclosed in the speaker cabinet. Also, you can think of it this way: instead of one motor (magnet / voice coil) for the midrange frequencies, now there are several, which greatly increases power handling capacity and reduced the distortion associated with power compression. Also a much greater cone area translates to less cone movement to produce the same output. In other words, you get the advantages of a large speaker without the expense and other drawbacks.
The mids are wired 3 in parallel x 2, and then the triplets wired in series for a total nominal impedance of around 5.3 ohms. The woofer I'll use for these speakers is an 8" Seas that has a 93db efficiency.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caFlame Testing My 10 Channel AmpJohn Heisz - Speakers and Audio Projects2023-07-28 | A little bit of hype in the video title, but part of the build is occasionally stopping to run some tests to check conditions. In particular, I don't want this massive undertaking to go thermonuclear and set fire to my house in the process. All along I've been monitoring how hot it gets while doing different things and everything looks good, so far. Why test with music instead of dummy loads? Because this will be playing music so it presents a more realistic scenario for the amps. And I've also tested into dummy loads, it just not as dramatic for video. Of course this is with the amp sitting wide open and the temps will go up when the front and top cover go on, but I don't think it will go up enough to be a concern. It will go up even farther in a warm room stuck inside my equipment stand, but still should not enough to worry about. There will be more testing as I make more progress.
The amp started out cold (18 degrees C) when I switched it on in the morning. The heatsink temp went up to around 24 degrees after running for around two hours, then I turned on the music and let that play for over an hour. Only 4 of the 10 amps were driven, but the output power would be about equal to what it would be with 8 channels driven at high volume into my 4-way speakers. For comparison, my older 6 channel amp runs at a slightly higher idle current (40ma / output with 4 outputs on each amp board) and has smaller heatsinks. It sits at around 50 degrees C at idle and has hit 70 degrees when driven hard. I built that amp 13 years ago and it's been in continuous operation ever since.
Another comparison is the Yamaha HTR I'm currently using in my listening room. That runs just slightly above ambient room temp and I've yet to notice any significant amount of heat coming from it. Based on that I know it is also running a fairly low bias current, yet it has amazingly low distortion and noise performance. It has 7 channels in a much smaller case with much smaller heatsinks.
By contrast, the Onkyo 2 channel receiver I have gets quite warm, but has a just barely audible amount of hiss when you put your ear to the tweeter. It is running at a much higher bias current and unless you go to extreme lengths to make a very smooth power supply, you give up some noise performance when you push up the idle current.
Some will swear that a higher bias sounds better (pure class A is regarded as the best sounding solid state amp topology), but I'm not aware of any blind testing that backs up that claim. The A in class AB is the part of the output that's running in pure class A operation. That is, the transistors do not switch off. For best efficiency, you want just enough class A operation to prevent crossover distortion. Crossover distortion happens when the output transistors switch off completely. Some amps push that class A mode up (via higher idle current) to cover the first few watts of output, but the cost is lower efficiency and much higher temperatures.
For me, the proof is in the low distortion measurements. If it's faithfully reproducing the signal and has the power to do that with authority, that's all I need from an amp. I'd much rather have the amp running cooler and lasting longer as a result. Any audible difference would be so small that it couldn't possibly offset the lower efficiency and higher temps.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caPutting the Amp Boards Together and testing / measuring themJohn Heisz - Speakers and Audio Projects2023-07-25 | Time to put the amp boards together and get them tested and measured. Since I started with a properly made prototype, I know these will work (providing I don't make any mistakes), but the testing and measuring just confirms that they are working correctly. If you want a look at the schematic for this amp, you can see that in this video: youtube.com/watch?v=Qe9H07JlT6w Putting 10 of these together took several hours, and then several more hours to run the measurements. You need to be in this for the challenge and because you love it, because you aren't going to save much money and you are certainly not going to save time doing it yourself. That said, it's hard to beat the level of satisfaction that comes from designing and building something complex from the ground up and having it work exactly like it was designed to.
The measurements I made are limited by the test equipment. Using a computer and sound card / audio interface isn't the same as a $50,000 Audio Precision spectrum analyzer, but it will tell you whether the amp is "good enough". THD, noise and IMD are all well below audibility and that's all that matters. Also the harmonic distortions are declining from the 2nd out, and the higher order harmonics are extremely low. What does it sound like? It sounds like an amp! Amps that are competently designed that don't inject harmonic distortion intentionally all sound the same. If you want to hear this one, there's a short sound clip at the end of this video: youtu.be/fg5CEx_l0aE
Much of how the amp will perform is dependant on the power supply that feeds it. In particular, you need plenty of power on tap to deal with transients. These amps will typically run in the 10 to 80 watt range, but are capable of putting out 150 watts each for brief intervals. That gives dynamic overhead so that the signal is never clipped, even at higher volumes. While this is a 10 channel amp, 8 of those channels will be used to power just 2 speakers - my active 4-ways. So in reality, a better way to view it is like a 4 channel amp, since ultimately it will power just 4 speakers. That means that the output power is spread out over 4 of these amp boards for each 4-way speaker.
One of the challenges when talking about complex issues is how a lot of people don't actually listen to what you are saying. Instead they find the first thing to react to (often just the video title...), so they can post a comment meant to dispute what they think you are saying. Very few of the viewers that commented on my last video understood the points I made in that video. And as I've been doing the YouTube thing for 12 years now, it comes as no surprise, but I thought I went above and beyond to make myself clear. I even wrote a very long description (long enough to trigger the "your description is too long" warning from YouTube) filling in details and clarifying points I made in the video. But then you'd have to read that AND be willing to understand it as well. It can be frustrating!
So, I'm subjective where it makes sense and I'm also objective when that is the best approach. For example I measure speakers! You've seen me do that! BUT that's just to evaluate what's going on when I'm designing a speaker. OBJECTIVE data of limited value. That objective data is used to help make the design as close to "technically" perfect as possible, but, at the end of it, they have to sound good, and that's SUBJECTIVE! If I don't like how they sound based on the objective measurements, I will make changes based on my subjective preference. That's why speaker measurements of the type I was talking about are misleading. They only show ONE layer of a multi-layered problem. They conclude that a speaker MUST sound good because it measures well and for most people that will be true. But if you want to know exactly how a speaker actually sounds, YOU have to listen to it in YOUR room. You may love it or you may not - that's the part that goes BEYOND the measurements.
Remember the side speakers I just finished? How I spent a lot of time designing the crossover and settled on a design based on the measurements? And then made those crossovers? But when I assembled the speakers, the eagle-eyed viewer might have noticed I added a capacitor on the woofer. Why? Why did I do that? Because it SOUNDED BETTER with that cap added. It pulled a bit more energy out of the upper midrange and they sounded better to ME. Were they still flat? Nope! But they sound great to me in my room and THAT'S what matters.
Where sound quality of a system is concerned, the three biggest factors are: - your hearing / listening preferences - the room - the speakers These will make the greatest differences in how a system sounds. That's why I'm singling out speaker measurements as misleading, because the speakers play a major role in the system and they are intimately connected to the other two items listed above. They play in the room and you listen with your ears. I know that seems like I'm overstating the obvious, but it seems that too many people have not made that connection. Other components, like the source, amp, dac, etc. can make a difference (sometimes a pretty big one), but not as significantly as the three above.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caA Rant about Speaker Measurements - They are Mostly BSJohn Heisz - Speakers and Audio Projects2023-07-20 | PLEASE READ THIS! IT'S DEEP! Don't misunderstand what I'm saying - measurements ARE important, but it's my opinion that they are of limited value when used to judge how a speaker sounds. They can tell you what the speaker is doing under ideal conditions, but they don't include the other major components of the listening experience: the room and the person listening.
Speakers are a complex system and you can't arrive at easy, simple answers when you try to objectively assess the performance of a pair. There are some widely accepted "rule of thumb" guidelines that can give you insights as to how they may sound, but there are no written in stone rules. Flat response and good off-axis response are two of those objective guidelines, but you have to remember that musical enjoyment is a purely subjective experience. What one person loves another may not care for, where sound "quality" is concerned. There's the expression that "beauty is in the eye of the beholder" and that certainly applies for audio when you swap "eye" for "ear".
Whatever music you are listening to sounds the way it does to you due to three major factors: - the speakers - the room the speakers are playing in - your ear / brain combo, where the brain interprets what the ears are receiving. "Interpret" is a word that allows a lot of variability. Your hearing system isn't perfect - far from it - and it is subject to a long list of factors that can influence it. All three factors are interdependent and together they determine what the listening experience will be. If you move the speakers to another room, they will sound different. If you are stressed and unable to relax, they will sound different. Not different in reality, but in your perception of how they sound through your ear / brain interface.
On top of this there is the fact that there isn't an exact representation of how a piece of music is supposed to sound. Music isn't like an engineering sample kept at a constant temperature in a sealed vault and taken out when needed to compare with another sample for accuracy. It was recorded and produced and nowhere in that chain did anyone actually hear the finished work until it was played back on a system in a room and into ears that is different from yours. The best you can do is get close to how it's supposed to sound, because there's no exact reference to ensure exact reproduction. So that throws the concept of accuracy out the window, since there isn't a precise point of comparison. In other words, music, and this is probably the reason why we can listen to the same piece over and over, is a singular experience every time you play it. Like a snowflake, no two listening sessions are exactly the same. And none will be exactly what the music is, because what the music "is" doesn't really exist.
Where measurements are needed is during the design process. The speaker designer can use them to determine whether there are fixable problems. For example if he listens and hears something isn't quite right, he can use measurements to pinpoint where the problem may be. On the other hand it's entirely possible to design speakers without measurements. Will they be "accurate"? Probably not, but as I said above, accuracy isn't a possibility anyway, since there isn't a precise reference. Think of it this way: While the musicians were playing were they measuring how accurate their performance was? Did the engineer measure how accurate his mix is while producing the music?
So if objective measurement isn't of much use, are subjective reviews better? Well, it depends on what the reviewer likes to listen to - it's called subjective for a reason. It also depends on the other factors listed above, so there really isn't any way to know for certain based on either objective or subjective review whether you will like a pair of speakers. The reviewer isn't listening to them in YOUR room or with YOUR ears and he isn't YOU. But chances are you WILL like them, if they were competently designed and you aren't going in looking for problems to "discover". And as I said in the video, even if you don't love them to begin with, you will get used to how they sound and possibly grow to love them.
Although I didn't mention it in the video, another example of this is creating "upgrade" kits for retail speakers, where the speaker is measured and the upgrade makes the response flatter. Does it sound better? Why was the speaker designed that way to begin with? Could it be that the designer WANTED it to sound like that? I know I'd be pissed if someone undid the work I did to justify selling overpriced crossover parts.What Does My New Amp Sound Like and How I Learned ElectronicsJohn Heisz - Speakers and Audio Projects2023-07-16 | I'm probably downplaying how much actual electronics knowledge I have, but my point is that I never did gain a proper educated understanding of it from a purely academic point of view. I can't do the back-of-the-envelop math to describe how a circuit will perform like guys who have that academic training can. But what I can do is take a circuit, sim it to see what it's doing, modify it if I need it to be different in some way and then (and this is the big one) build it and test it in the real world. At this point in history, nearly everything you can imagine has already been designed in the world of audio circuitry, so it's just a matter of adapting what you need to work the way you need it to work. Now, like I said in the video, if I had my time back I would have put more effort into the theory and math when I was younger. Eager to just make something instead of studying, I didn't realize that I would have been better off in the long run if I had traded the soldering iron and the parts I was about to ruin, for those books I should have read more often.
Onward to the amp and the demonstration of it starting up. No audible turn on thump is a plus, but that may change when the active crossovers are in the signal path. I can add circuitry to mute the amps while the crossovers start up, but that complicates things and I want to wait and see how it works without it. Hiss and hum are as nonexistent as I would ever need, and remember this is the amp running out in the open with wires going every which way all over the place. That sound clip was recorded with my high quality lav mic just inches from the speaker's tweeter and boosted by 30db on top of that, so if there was any noise you would very easily hear it. But again this is without the crossovers connected, so subject to change. But I'm pretty sure the crossovers are as noise free (and hum free) as the amps are, so I'm not expecting any issues. The next phase of the build is to finish the amp boards and test those individually before installing them. That's the tedious and time consuming part, and when that's done I have an equally tedious task to do - finishing and testing the crossover boards and getting those wired in.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caBuilding a 10 Channel Amplifier - Assembly Details Part 2John Heisz - Speakers and Audio Projects2023-07-14 | With the prep work done on the base and dividers, I sprayed them matte black. The two transformers that will power the amp are located inside the centre, on each end. There is a lot of wiring contained in that space, running back and forth, and the partitioned area keeps them somewhat tidy. I did have to remove the dividers again to drill 1/2" holes for wires to come through. Originally those wires were going to go up and over the dividers, but I figured it would be better to have them go through down low. They connect the power supply boards (the two bigger boards in the centre) with the four power distribution boards at the base of each heatsink. Also mounted on the top of the centre area is the main power relay board at the back and the +/- 15vdc supply board for the active crossovers at the front. This is directly above the second transformer and is fairly close to it, so I put a strip of tape on top of the transformer to insulate it. I also made new standoffs from harder plastic to replace the ones I made from 1/4" tubing. If you missed it, you can watch the first assembly video here: youtu.be/3ir4NwDFYio
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caBuilding a 10 Channel Amplifier - Assembly Details Part 1John Heisz - Speakers and Audio Projects2023-07-12 | The back panel for the amp is made from 1/8" thick aluminum and I engraved the labels in it with my CNC using a V groove bit. The engraving was then filled with black paint and I sanded off the excess after that dried. That method works great if the font is big enough. You might keenly observe that I added more labels to the back plate - I forgot to mark the outputs for the individual speaker drivers (woofer, tweeter, etc.) the first time. The case I'm working with is one I partly build 15 years ago and I show that in this video: youtu.be/Qe9H07JlT6w The rest of the video concentrates on getting the power supply parts prepped and installed. There are four power distribution boards that sit at the bottom of the heatsinks on the sides that feed the power amp boards that mount on the heatsinks directly above. This keeps the wiring somewhat tidy and the leads short. The two dividers that run down the middle of the case partition off the centre area where the transformers are. These dividers add a lot of structural stiffness to the bottom panel and also provide space on top to mount the power supply PCBs.
It's worth pointing out for anyone who hasn't done this kind of thing that this 10 minute video represents hours and hours of work. None of this is as easy or fast as I'm making it look, and even a small thing like not being able to remember where I put a particular part than needs to go in next sets you back orders of magnitude longer than this video. A lot of planning and off camera work went into this, on top of the work I did 15 years ago to build the case to begin with. If you are thinking of this as a way to save money instead of buying a ready made unit, you are missing the point entirely. For me designing and building this amp is entertainment of the challenging sort. Much like training, preparing and gearing up to climb mountains is for someone else, or rebuilding a project car from the ground up. Sure I'll have an awesome piece of hand-built equipment after I'm done, but it's the experience of doing it that I value the most.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caThe Solder Spanker® A Clever Invention for PCB Desoldering, or Idiotic Idea?John Heisz - Speakers and Audio Projects2023-07-05 | This was an idea that just popped into my head while desoldering my latest mistake, and while it does work, can mostly be seen as a bit of a novelty item. I know (I KNOW!) that there are better desoldering solutions out there, but this one has the advantage of being made from stuff I already had, so only cost me the time to do it. And desoldering isn't something I'm doing all day every day - it's actually a rare event - so a simple solution like this makes sense. It takes some practise to get good at it. My first time using it was in this video, and I hadn't got the timing down. You need to melt the solder, move the iron and release the board to knock off the solder in a fast, well executed move. Several times I released the board while the iron was still in the way and that took the spanking energy out of the motion. Will I use it? YES! I have several old PSB to depopulate and this will be very handy for that. The biggest plus in its favour is how it captures the solder that's flying off. It will also catch any components that break free, making them easier to find.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caPower Supplies with Soft Start for my 10 Channel AmpJohn Heisz - Speakers and Audio Projects2023-06-30 | Since I'm using two different transformers, I need two separate power supplies. These supplies have a soft start circuit built in and in this video I go over how that works. In a nut shell, the thermistor is all that's needed for the soft start to work. But there are a couple of good reasons why it's better if you bypass it after it has done its job. First is that if you bypass it, it will cool down and last longer. Second is that when the amplifiers are not drawing enough current, the thermistor will cool down anyway, and as it does its resistance goes up, which lowers the supply voltage. When you short it with a relay, the relay carries all of the current without heating up. But there has to be a short delay before the relay switches on so that the thermistor has time to work. I used the switching circuit from Rod Elliott's website to do that, and he gives a more detailed description of how it works: http://sound-au.com/project39.htm To power the soft start bypass I dropped the 40VAC from the power transformer down to less than 10VAC with a resistor and a pair of 1uf capacitors. That lower AC voltage is then rectified to power the circuit and switch the 12VDC relay. This has the advantage of not needing a small transformer to run the soft start. Also it doesn't heat up like resistors would to drop the rail DC down to a usable voltage. On the board as well is what's known as a ground lift. It consists of a 10 ohm power resistor and two diodes wired back to back. The lift "separates" the supply ground from the chassis (earth) ground, but still provides a physical connection between the two. This can help greatly with ground loop problems that cause hum. In the video I also show the power distribution boards that feed the individual amp boards. These reduce the wire runs inside the case and also put the supply capacitors very close to the amp boards, which should improve (very, very slightly) transient response. They are also a convenient place for the rail fuses for each amp board. Since I have two supplies and 10 amplifiers, one supply will power 6 amp boards (these will drive the tweeters, midranges and midwoofers in my 4-way speakers) and the second will power the other 4. That other 4 will drive the woofers in my 4-ways, plus the bass shaker in my seat and have one channel left over for a possible centre channel speaker.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caTesting the Active Crossovers for my 10 Channel AmpJohn Heisz - Speakers and Audio Projects2023-06-24 | These crossover boards are a key component in my 10 channel amp build, and I have to make sure the board layout works properly before I order the professionally made PCBs. Each board contains an input buffer, a two stage high pass filter, a two stage low pass filter and an output buffer that has some gain and also has a trimpot to adjust the output level. Credit and thanks to Rod Elliott's excellent website for this design: sound-au.com/project09.htm. His site is a wealth of practical knowledge and projects that I've been using for nearly 20 years. The linked article has a detailed description of how the crossover works if you want more info. The filter stages combine for a 4th order slope on the high pass and low pass, letting a limited range of frequencies through. In this example, the board is set to drive the woofer of my 4 way speakers from 80Hz to 350Hz. Another board will drive the midwoofer from 350Hz to 900Hz, and so on. There will be 10 of these, one for each individual amplifier board. Testing was done first with my scope just to check if it actually works. While the circuit design is proven, the wildcard is the board layout and whether I made any mistakes doing that. I then set up my computer to run REW to measure the frequency response. This is done in a similar way to measuring a speaker (or room), except instead of using a microphone, the signal is fed directly through the crossover board. As shown in the video, the measured response very closely matches the simulated. The next step is to finalize the board layout and order the boards, and then I can start putting the amp together. Active vs passive: is a topic for another video. You can watch part 1 in this series here: youtu.be/Qe9H07JlT6w
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caDesigning and Building a 10 Channel AmplifierJohn Heisz - Speakers and Audio Projects2023-06-15 | READ ME! Why am I building this? Because I can and want to, mostly. Also because I don't entirely trust the DSP solution for speaker crossovers. Active analog filters are set and can't lose their programming, barring a catastrophic (and extremely rare) failure. You might say that failure for DSP is extremely rare, but it's already happened to me. After a power outage, my miniDSP 4x10 lost it's configuration settings and luckily I checked before played anything. Having the full signal at high volume going to my expensive tweeters would not be a great start to a relaxing evening of listening. The amp design is relatively simple, a typical three stage configuration with good quality parts. I tested the prototype for operational stability and thermal stability and saw no issues. Not shown in this video (but I'll do it in an upcoming one) the stability testing included adding capacitance to the output. I used a 1uf cap and the amp did not break out into oscillation. Square wave testing shows a fast enough slew rate and there will be more testing when I get the professionally made boards to do the full power tests. Note that this is an integrated amp that has 28db of gain and doesn't require a preamp. The case I built is a little rough and not even close to finished. But it is HUGE and has plenty of space for the ten channels I want to put inside. Yes, I've settled on 10 channels - 8 for the main speakers and two to spare for a possible centre channel and the other channel can run the bass shaker in my seat. I'll have to rework or remake the back panel and make a cool looking front and top panel, plus install some dividers inside. The transformers were salvaged from vintage power amps and are easily powerful enough to run all 10 channels at good listening levels with headroom to spare. Each will have its own large capacitor bank for smoothing and reserve, with a soft start circuit on each. Conveniently, the larger transformer also has a low current 22vac winding that's perfect for the active crossovers supply.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caYou are Thinking About Sound the Wrong WayJohn Heisz - Speakers and Audio Projects2023-05-24 | Most people tend to think of sound from a speaker as air moving. This leads to the idea that something that will block wind (like thin plastic) will also block sound. The air is moving, but there is no "flow". Instead, think of that movement as shivering - it's vibrating very slightly but not going anywhere. As with all solids, some sound will reflect off of the thin plastic, but almost all of it will pass right through unobstructed. Think of light hitting a pool of water - some reflects and some goes through so you can see the bottom of the pool. So a damping material like rockwool performs essentially the same as it would in its raw state, if it is sealed inside a plastic bag. Sound is energy that travel through and acts upon mediums. Mediums are any solid, liquid or gas (like air) and they vibrate when sound passes through them. They can also reflect the energy. If the sound is travelling through a medium (like air) and if it meets another medium of different thickness, density and mass some of it will reflect. The new medium (like a wall) will reflect some of the energy and let some pass through. For example a thick, solid concrete wall will reflect almost all of the energy that hits it, while a thin wall made from lighter, less dense material will only reflect the higher frequencies and let most of the bass frequencies pass through. You can hear this effect easily with your stereo playing in another room. Damping absorbs energy and converts it to heat. When sound passes through a damping material, some of it is converted to heat and used up in that way. That's how the piece of rockwool I put inside the speaker stopped the standing wave - it absorbed the excess energy from that standing wave and converted it to a very small amount of heat. Sound is not simple. Most think of it in 2D terms, when it is fully a 4D process. It moves through 3D space with a beginning and end time. It usually starts at a single point, but then expands out in all directions from that point until all of the energy has been converted to heat. This expanding is called propagation and the sound energy is spread thinner and thinner as it happens. Think of a balloon being inflated and how the rubber gets thinner as the balloon gets bigger. There's still the same amount of rubber there was when the balloon was not blown up, but it's now spread over a much larger area. For sound to dissipate quickly, something has to speed up the conversion of that sound energy to heat. That's the function of damping, like that rockwool I used.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caWill Speaker Damping Material Still Work if its in a Plastic Bag? Lets try it and find out.John Heisz - Speakers and Audio Projects2023-05-16 | Bag it! If you are concerned that the plastic will crinkle and make a sound in the box, use cloth instead. Hey, you have a sewing machine, right? No? A stapler, then! Glue gun! Seriously, there's little chance the bag will make a sound, since the inside of a speaker isn't a wind tunnel, and you'll want to keep it away from the port anyway. The port is windy, not the box. Got it? The point is that SOUND GOES THROUGH thin stuff! RIGHT THROUGH! That includes thin plastic! RIGHT THROUGH! Sound isn't air. Sound isn't wind. Sound is energy and it goes RIGHT THROUGH thin stuff!!! Seriously, again, thin plastic is perfect since it will completely contain the fibers you are losing sleep worrying about. And the sound passes RIGHT THROUGH IT! Like MAGIC! So you can use it for those intimidating acoustic panels you want to build, but are terrified of the life-ending cancer-causing fibers that will devour your existence from the inside out! Just bag it, bro!
The big reveal on the recorded music is that the shallow box was B and the deep box is A. But I may have skewed the results of the guesses for each by leaving the label on each track. Also, guesses like this have a cascade effect, where guys will peruse the comments already left to see what the majority is going with, and may use that as a deciding factor if they are not quite sure. If there's a difference between the two, it's a very small one and in my opinion not something to be concerned with. I know for a lot of guys any difference is a BIG difference, but my conclusion is that I wouldn't hesitate making a shallow speaker box if I need it to be shallow. I'm thinking very specifically about how the driver is mounted in a transmission line speaker, usually partway down the length of the pipe and not having much space behind it.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caIs a Deep Speaker Box Better? Tested with Surprising ResultsJohn Heisz - Speakers and Audio Projects2023-05-14 | The traditional wisdom says that if the driver is close to the back panel of the speaker box, you'll get very obvious reflections back through the cone that colour the sound. While this is now widely accepted as true, I thought it would be interesting to actually test it and see first-hand how much of an impact it has. The two boxes are nearly identical internal volume of 12 liters (the deep box is very slightly bigger). That volume works best for the driver I'm using for the test, a Seas coax H1144. The deep box is 8" from the back of the front baffle to the inside face of the back of the box, while the shallow box is 4" deep. I used the same driver (I only have one of these), crossover and test setup for each box. The shallow box is just deep enough for the driver to fit - the back is just 1/4" from the back panel. Measured first without stuffing, the tall shallow box shows a disturbance in the 300Hz range. This can be the "back through the driver" reflection mentioned above or it can be a standing wave. Adding stuffing (I used the same piece of rockwool in each box) shows no significant change for the deep box, but has smoothed out that 300Hz wiggle in the shallow box, proving that it is a standing wave problem. The standing wave happens up in the shallow box because it is taller and the distance from top to bottom is great enough to support a standing wave in that 300Hz region. The rockwool is damping material that absorbs sound energy, breaking up that standing wave. Tangentially, this also demonstrates that standing waves are only a problem when the box is big enough inside to support a standing wave in the lower midrange frequencies. Note that the deep box shows no improvement when stuffed, indicating that there are no standing waves of any significance to damp. So making a small speaker box with rounded or angled sides won't be effective for preventing standing waves, when they wouldn't be there to begin with. Finally a listening test using both boxes. The mic is set up around 20" from the speaker on tweeter axis for both boxes in my listening room. I deliberately withheld which box is which, leaving you to decide based on listening only. Give it a try and leave a comment, and I'll reveal the results in a future video.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caThe Best Center Channel Speaker is... AND The Coolest Album Cover of All TimeJohn Heisz - Speakers and Audio Projects2023-05-10 | The mighty coaxial driver is the ideal unit for a center channel speaker because it's a single point source that doesn't suffer from the off-axis issues that a standard speaker turned on its side will have. I bought this one around 14 years ago and I'm pretty sure it's out of production now. But it is a very good driver and perfectly suited for the job I have in mind. That is to set up a rear speaker directly behind my listening position and wire that into the side speaker's positive terminals. This is the so called Hafler circuit that only outputs the difference between the two channels. Often used as a low cost "surround" setup, it adds a subtle ambience to the sound field that's quite pleasant. Along with that, I'll be designing and building a new transmission line subwoofer that this rear speaker will mount in. This will give me the opportunity to compare the transmission line to the vented box I made a few years ago and see if there are any real advantages. New CD's! ELP, Tom Petty and Bob Seger. Long time favourites of mine that regularly listen to today.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caMaking and Installing the Crossovers - OB Speakers FinaleJohn Heisz - Speakers and Audio Projects2023-05-02 | I finally have this pair of speakers done and I'm enjoying the heck out of them every night in my society deprivation chamber (aka, listening room). Sanding to 220 grit, then wiped on three coats of a tung oil blend, letting each coat dry 24 hours. Then top coated that with two sprayed on coats of satin water based poly to give them real protection and get the gloss level I want. While all that was happening I assembled the crossovers. The circuit board I used was a thin piece of solid cherry and I connected the components point to point. Drawing the schematic on the first one really helped, then I tested that before doing the second one. Fishing the wires through went okay, but if I were to do it over again, I'd spend a bit more time making sure the passage through the base was smoother. Or just put the wires in while assembling the base - that would be easier. How do they sound? Great! But keep in mind that these were designed and made for a very specific purpose, and that's to replace the first reflection off the side walls in my listening room. And for that, these are perfect. If you don't know what I'm talking about, check out the first video in this series where i describe this reflection replacement principle. Click the link below. This is part 7 (the finale) in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caMore Than One Subwoofer is Better? Lets try it and Find OutJohn Heisz - Speakers and Audio Projects2023-04-24 | Multi-sub. Does it work? In this video I show a fairly rough test I ran using the 4 infinite baffle subs that are located in the front wall of my listening room. I also have a smaller sub that I can move around and I put that in 6 different locations to see the results. Just from measuring the 4 fixed subs I can easily see that the frequency response improved. It was flatter without any of the dips the individual subs had on their own. Adding in the mobile sub gave a solid boost in the low end, even though the output from that sub is a lot lower than the fixed subs. So yes, the multiple subwoofer concept is a winner, in that it greatly improves the measured frequency response at the listening position. However, I did not see a significant difference in the reverb time from one setup to the next. One of the claims for the multi-sub setup is that it can "fix" room modes, but I see no evidence of that. Granted, I didn't run through every possible position for the mobile sub and my fixed subs can't be moved at all. Also, my room is fairly well treated to deal with low frequency reverb and maybe the effect would be more obvious in an untreated room. I'm inclined to think that if you can effectively nullify a room mode by careful positioning of an additional sub, it's going to be a very tricky task. You'd DEFINITELY need to run measurements to check whether you are actually producing an improvement, and that would take a lot of time. And after all that, would the improvement be significant? Like I said, I saw NO real difference in the reverb time with each test, but I DID see a significant response improvement. The 6 locations for the mobile sub were side left, side right, middle of the room, back corner left, back corner right and middle of the back wall. I'm pretty sure the best response was with the sub on the right side, with middle of the back wall a very close second. Since the middle of the back wall is the most suitable, that's where a new subwoofer will go (yes! future build!). My room is 14' x 14' with an 7' ceiling. The dominant room modes are at around 38Hz and 70Hz. I've done extensive work to acoustically treat the room to reduce the reverb time and I have a few videos on this channel showing what I did, so please check those out.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caBad Hearing? Watch This Before you get Hearing AidsJohn Heisz - Speakers and Audio Projects2023-04-21 | I thought it might be informative to run through my hearing aids experiences for anyone that's thinking about getting them to improve their music listening. First I'll say up front that yes, definitely, the hearing aids make a massive improvement. They fill in the frequencies that are missing and do that remarkably well. But, and this is the big one, they MUST be set up properly to do that. The audiologist you go to will test your hearing, tune the devices and then measure what they are putting out, but that can't measure how your ear / brain is receiving that new input. And unfortunately some tend to not listen when you say the hearing aids don't sound right and dismiss it as something you just need to get used to. I believe that when I got my first pair back in 2014, the audiologist (who was older and very experienced) knew that you can't just go by the numbers, and may have dialed back the high frequencies enough to avoid all of the problems I ran into years later. So when they were set up, they sounded perfect to me. Everything was clear and undistorted. Fast forward to 2021 and I want to be retested and see if any improvements can be made. I was building my new listening room at the time and thought I should try to get my hearing as good as it can be. As outlined in this video, that started me down a path of frustration while I went to 15 different appointments over the next two years. After the first round in 2022, I gave up, and settled for the "close enough" settings he had made. The only issues were that the limiter was set too low and the right ear was quieter than the left. They still sounded very good - he was able to get them close to the way they were set up originally in 2014. So, 7 appointments over 3 months to ultimately degrade the quality. Ahead to the winter of this year (2023) I decided to try again. I made an appointment at a different place and basically went through the same thing over again. The new audiologist tested my hearing and then I told him the problems I had before, including the limiter and balance issue with my old hearing aids, and made a point (several times) of saying that the old ones sound great, other than the balance and limiter. Of course he quickly ignored that and just went about doing it the way he was trained to do it. I would have thought, even just for the sake of curiosity, to start he would look at the settings on my old hearing aids to get an idea of what they are doing and go from there. But no, it would be 4 more appointments and two new models of hearing aids before I basically forced him to do that. And even then he couldn't resist "tweaking" those settings, by adding too much high frequency boost, and meaning yet another trip back for yet another adjustment. In the end I'm still using my old hearing aids, but he successfully got them back to what they used to be when they were first set up back in 2014. Full circle with no improvement, in other words. New hearing aids have a bunch of bells and whistles such as active noise management that seems to mess with the sound too much, ruining the pure quality you get from just straight amplification. Or at least that's my impression from using various newer models over the last 3 months. None of the ones I tested sounded as good as the ones I already had. In fairness that might be the fault of whoever set them up, but good luck finding someone that can get it right. Most of the older audiologist that have years of experience have retired, leaving it to younger people with a solid understanding of the process, but very little practical experience. They can run the measurements and set up the hearing aids according to those measurements, but don't seem to realize that that's only half of the equation. The other half is how the ear / brain is receiving and interpreting the new input, and the only way to "measure" that is to listen to what the customer is saying. "It sounds like nails on a chalkboard!" "Oh, you'll get used to that."
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caNew Speakers Final Assembly and Fixing a Big MistakeJohn Heisz - Speakers and Audio Projects2023-04-14 | This time I finish putting together the stands and then mount the baffles on the stands. In doing so, I wasn't as careful as I should have been (maybe subconsciously intentional to give myself a good excuse to inlay the walnut) and to fix the problem I routed out the pocket deep enough to glue in a piece of walnut veneer. The veneer corrects the glue squeeze out / poor fit and also gives the colour contrast I wanted when designing these. Of course, inlaying the veneer like I did makes it possible to skip routing the pocket through the bottom of the baffle to begin with, and just attaching the baffle directly to the angled upright of the stand directly. I could have even used screws because the walnut veneer would hide them. In the end they would have looked the same but would have taken a lot less time to build. Let's say that's a lesson learned for next time, right?
This is part 6 in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caLets be Honest, these Stands Make the SpeakerJohn Heisz - Speakers and Audio Projects2023-03-05 | The stands are what make this speaker design look neat. But they are fairly complex with lots of angles and a good share of that complexity is hollowing out the base for the crossover components. After cutting the parts I used my adjustable router template to cut a recess. And while I was at it managed to chip the thin end which encouraged me to add the steel bottom plate. The steel will cover the opening, but also provide a bit more weight on the bottom to make the speaker more stable. I used solid cherry to make the parts and had to make sure I got all of them from the piece I had. This step in the project took most of a full day, so while these speakers will look fairly simple when done, these are among the most complex ones I've built. This is part 5 in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caQuitting YouTube To Start a Speaker Business...John Heisz - Speakers and Audio Projects2023-02-27 | I would like nothing more than to start a speaker business. I have the passion , the technical know-how and the woodworking talent / experience to pull it off. But as I explained in this video, I'd have to either do the impossible (believe in the mystical mumbojumbo that you have to say when trying to market the products) or become a lot better at lying than I am now. And then there are all of the other normal obstacles to overcome to market a new product. You say that surely you don't have to go to those lengths just to sell speakers, but you have to look at the market and what they want and expect. To give your product the required cachet to appeal to the audiophile community, you have to be a respected part of the community and talk about the same things as the people in that community. That's where the mumbojumbo comes in. You will alienate too much of the market if you stick with a reality based point of view. Undoubtedly I would sell some speakers, but without that magical quality that only comes from indulging fantasy, not enough to become a worthwhile venture. I used "The Shinning" as an example of this. If King wrote reality based stories that were devoid of any supernatural themes, he wouldn't be a household name. He would still be somewhat successful, but nowhere near what he is today. Same for so many movies and TV shows - they dip into the mystical because that's what appeals to most people.
New CDs! Pretty Hate Machine is a longtime favourite of mine and this 2010 remaster is worth the upgrade. Led Zep, I was never a huge fan, but I like nearly everything they've recorded. The so called remasters were just slightly better than the originals I have.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caThe Best Listening Experience I ever had PLUS 2 New AlbumsJohn Heisz - Speakers and Audio Projects2023-02-20 | My stereo headboard was an awesome listening experience (at least to my 16 year old, less discriminating ears), but it's downfall was that it was too restrictive. When laying flat on my back with my head in the box, I couldn't move around. That's the primary reason why I abandoned it, but I also got itchy to build something new with those speakers. While cheap coax car speakers probably couldn't even be in the same building with audiophile quality gear, they sounded pretty darn good in that headboard. Again, though, I was at most 17 at the time and my hearing was still untouched by the 30+ years of construction noise I used to damage it. And being only human and subject to bias, whatever I made almost always sounded good to me.
New music! Yes, two new CDs have arrived and my budget has been expanded because I successfully used clickbait to entice a few more of my subscribers to watch one of my excellent videos. I should disclose that the inflated budget has already been blown and I should have some new disks in hand shortly. This time two from Supertramp: "Crime Of The Century" and "Even In The Quietest Moments". Both are loaded with great songs that are perfectly recorded, arranged and mixed.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caBuilding my new Speakers - Cutting out the Driver Holes and RecessesJohn Heisz - Speakers and Audio Projects2023-02-14 | With the baffles shaped and the notches cut out for the stands, I can layout the location for the drivers and get the holes and recesses cut. I'm flush mounting both drivers and using my trim router with a very simple circle guide. Here's a link to the video where I made that circle guide: youtube.com/watch?v=1aWh4h3uMzo Included in this video is a pretty neat way to get the centre back after you've cut it out. I made the mistake of cutting the recess to small (the tweeter wouldn't fit) and I had to re-cut it after I cut the hole. I used dowels that are the same size as the router bit to put the plug back and it worked like a charm. This is part 4 in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caWhat is Speaker Cone Breakup?John Heisz - Speakers and Audio Projects2023-02-09 | Cone breakup is what happens when the cone is moving faster than the material it's made from can keep up with. It starts to bend and ripple, causing sounds that are generally objectionable. This happens at higher frequencies and you need to design your crossover to try to cut off the drivers response before it reaches the breakup region. Using higher order filters will more aggressively roll off the signal before the breakup and drive the level down below audibility. Where breakup will happen is determined by several factors: What the cone is made from, how stiff it is, the shape and the diameter of the cone are the primary ones. It's no accident or arbitrary decision why the cone is a cone shape - it it's the strongest geometry for resisting that breakup.
While I say I'm not an expert, I do know quite a bit about audio and I have a lot of practical experience. I've been messing with it since my early teens, so more than 40 years. The information presented in these videos is as accurate as I can make it, within reasonable time constraints. I don't have weeks to thoroughly research a particular topic, but I never go on my assumptions - I always check to make sure that I have the correct understanding of what I'll be talking about. And I ask you to do the same: if you think I've made a mistake based on your understanding of the topic, please take a few minutes to check whether you are right before commenting. And please also (and this is important) don't take the word of your favourite audio guru as a reliable source for factual information on these subjects. While I put in the time to verify that what I say in these videos is accurate, not everyone does. And there's also a strong motivation to say misleading things if there's a project being sold. I'm not selling anything here, I'm doing this for fun and because I'm very interested in audio. I also like watching videos on the topic and figure I would make some for other who have the same passion to watch.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caMaking the Baffles for my New SpeakersJohn Heisz - Speakers and Audio Projects2023-02-04 | Starting work on making my new speakers, I'm using solid ash hardwood to make the baffles. This is rough-sawn lumber, so the first step is to flatten one face enough to run through my surface planer. Normally I use a jointer to do that, but mines buried behind a bunch of stuff i don't want to move. Instead I'm doing it "close enough" with a handheld electric plane. After the board it planed flat I can cut off the edges to square it up. Then cut it in half to make both baffles. These will be joined to the base with a large notch in the bottom edge, and I used a plywood template to route that out precisely. The next step will be to cut the driver recesses and holes and start working on the base. This is part 3 in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caDo Acoustic Panels Really Work? Surprising Results...John Heisz - Speakers and Audio Projects2023-02-01 | Of course they work. But there are 2 conditions to meet: First, they have to be thick enough. Minimum 6" is recommended. Mine are 5.5" and that's close enough. Thinner panels only absorb higher frequencies and have little effect on the lower midrange and practically no effect on bass. Second, you need more of them to make a serious difference. I put a LOT of treatment in my room to get it to where it is now. Every bit helps, but don't expect miracles when you install 2 or 3 panels. Even though I showed the measurable (and audible) difference that just 4 panels can make when placed at the first sidewall reflection point, to get major gains you need to use a lot more. Treating the sidewall reflection WILL make an audible improvement to the sound quality, in particular clarity, and it's a great start. But if you want the kind of improvement I was able to get in my room, then you need to commit to doing a lot more. As shown in the video, an untreated room is a veritable blizzard of reflections that take what could be a high definition listening experience, and make it into a standard definition mess. Stop fooling yourself into thinking that all you need is the right amp or the right speakers or (absurdly) the right cable to get the ultimate sound in you echo-chamber room. Again, think of the headphones example. What do they say when they want you to listen to something very carefully? They say wear headphones. Why? Because headphones are the closest you can get to a reflection-free listening experience, outside of a real anechoic chamber.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caThe Dirty Little Secret of Open Baffle SpeakersJohn Heisz - Speakers and Audio Projects2023-01-28 | The dipole peak is caused by the interaction between the output from the front of the speaker and the back of the speaker. Depending on the width of the baffle it will cancel or reinforce at different frequencies, so you get a pronounced peak in the response where it reinforces (adds), and dips in the response where it cancels. This is most obvious in the first dipole peak at the lowest range of the driver's response, but also has an effect on the frequencies above that. To eliminate it altogether you need to make the baffle wider (at the top and bottom as well) than the lowest frequency you want to get from the driver. That's typically wider than practical. Another way to deal with it is to use separate drivers and vary the width of the baffle where they are located to get the best response. I did that in my main speaker build where I used a 15" woofer for the lowest range on a baffle with deep wings, then used progressively smaller drivers on the baffle as it narrows. The dipole peak problem was responsible for some of difficulty I had, but it was also a hump in the tweeter's response added to it that was the major cause. By shifting the crossover frequency up to 4KHz, it took a lot of the thunder out of the hump and flattened the response to an acceptable smoothness. The 5" midwoofer is happy to play up that high (as confirmed by the distortion measurements) and whenever possible I prefer to cross the tweeter higher to take away the stain of using it at lower frequencies. This may affect the off-axis response of the speaker, but the way I'm using these speakers it would be better if they were more directional.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caDesigning Crossovers and Measurements / ListeningJohn Heisz - Speakers and Audio Projects2023-01-25 | I started with a rough 2nd order crossover at 3500Hz and refined it from there. My first measurement showed a bit of peaking in the midwoofer response around 3800Hz, so I changed the filter on that driver to a 3rd order and lowered it to around 3000Hz. I then adjusted the 2nd order filter on the tweeter to that lower frequency and arrived at a pretty good response. I may do some more fine adjustments, but this is a very good start. I also tried a first order crossover on both just to see how that looks. Again, it let in a bit too much of the peaking in the midwoofer response, so I ruled it out. As for how it sounds, it's early yet, but I'd say it's very good. The midrange sounds clear and smooth and blends seamlessly with the tweeter. Lower midrange sounds full and neutal. I played a couple of songs (in mono) that I'm very familiar with to judge. Unfortunately, I can't record those in a published video, since that would be copyright infringement. Next step is to make the solid wood baffles for both speakers and that will be the subject of the next video. This is part 2 in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caNew Speaker Project - Concept, Drivers and DesignJohn Heisz - Speakers and Audio Projects2023-01-23 | Good news! I'm building another neat looking pair of speakers. These ones are open baffle 2-ways that I'll use in my listening room positioned at the sidewalls. Not surround speakers, but the reflection replacement idea I talked about in the video. The drivers are the Vifa P13WH10-4 midwoofer and the Scanspeak R2604 ring radiator tweeter. The baffle will be a solid hunk of ash 24" long, 2" thick and 8" wide. Crossover will be 2nd order Linkwitz-Riley at 3500Hz (subject to change). Yes, I used the "don't ever design a crossover with that online tool" online tool, but I've found it to be good enough to put me in the ballpark and I can tweak from there. Yes, I know all about using Xsim and the measured impedance and frequency response to design the crossover. That method rocks, but involves more prep work than I'm interested in doing for this project. I'll use a small class D amp to power these and will probably add a highpass filter to the input of the amp to keep the midwoofer from being over driven at low frequencies. This is part 1 in my series on designing making a pair of open baffle 2-way speakers to use as "surround" speakers in my listening room. I've created a playlist with all of the videos: youtube.com/playlist?list=PLQl9KPrpiIH-5l4QhxUYXHGhr-covK8n6
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caPlaying with a Bass Shaker Plus 4 New AlbumsJohn Heisz - Speakers and Audio Projects2023-01-15 | A bass shaker adds the final stroke of realism that even the best and biggest subwoofers can't do. By directly shaking what you are sitting on while you are hearing / feeling the bass produced by your subwoofers, it really sells the "I'm there" illusion. I though it might be even more realistic if it was mounted on the floor directly below my chair, because it would be shaking something bigger - more like the whole room is moving rather than just my chair. Since the hardwood flooring is cushioned by thin carpet, it can move slightly and may be better at transferring the energy to the whole chair. The results were not as good. Maybe if the floor was wood framed and not sitting on a concrete slab it would vibrate more freely. In any case I thought it was worth a try to see if attaching it directly to the chair can be avoided. New music! Three from The Police: "Zenyatta Mondatta" "Ghost in the Machine" "Synchronicity" and one from Metric: "Old World Underground, Where Are You Now?"
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caAcoustic Panels from the Future? and the Haas EffectJohn Heisz - Speakers and Audio Projects2023-01-11 | Rather than using drywall to finish the walls in a room, one could make cloth wrapped acoustic panels that fill the space and extend from floor to ceiling! And it could be reversible, with a different colour fabric on the other side! That's it, I'm doing it!! While the Haas effect points out something important about how our hearing works, it doesn't address what happens when two sounds converge at a single point at different times. Comb filtering (a series of peaks and dips in the response) occurs and has a detrimental impact on the original single. It reduces clarity because you have a disrupted response. Also, instead of just one strong signal, you have two with one reaching your ear slightly behind the direct sound. While this does give spacial cues that add dimension to the listening space, it also smears the sound that reaches your ear. There's a reason why they say to wear headphones when you need to listen to something carefully, since headphones are as close as you can get to reflection-free listening. Using the findings of this effect to claim that reflections are good and needed for proper stereo imaging ignores or minimizes the comb filtering that reflections cause.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caIs Carpet Better for the Floor in a Home Theatre / Listening Room?John Heisz - Speakers and Audio Projects2023-01-08 | Carpet? Short answer is that it works okay if that's all that you can do. If it's thick enough, it will take a lot of the echo out of a room and improve the sound. Even though it only works with the higher frequencies, It's effective because there's so much of it. The problems start when you want to take that improvement in sound quality to the next level. As you add proper acoustic panels that absorb a wider range of frequencies, along with the highest frequencies, you will reach a point where too much of the high frequency energy is being absorbed and the room will start to sound too dead. This is especially true if you do any treatment on the ceiling, for example mounting panels above the speakers and listening position. In my room I put a lot of time and effort into acoustically treating the room and carpet will actually be detrimental to the outcome. Carpet will absorb the highest frequencies that I'm trying to preserve in the room to give it a more lively feel.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caWhat Music do I Like? Four Albums I Just BoughtJohn Heisz - Speakers and Audio Projects2023-01-04 | What music do I listen to? I figured an interesting way to answer that would be to take the meagre proceeds from the videos on this channel and replace the CDs I used to have. And when I buy some new ones I'll do a quick show-and-tell. Tell me what you think of this idea. I've been listening to Neil Young for close to 50 years and he holds a high rank among my favourites. On the radio first, then on tape and then on CD before transferring those to computer and foolishly selling off the originals. To start off my collection rebuild, I picked three of his oldest, "Harvest", "Everybody Knows This Is Nowhere" and "After the Gold Rush". I also ordered his self titled "Neil Young" CD but haven't received it yet. I should say that I'm not into his newer stuff, preferring his work from before 1980. That dividing line has everything to do with the quality of what he's put out from purely a musical standpoint, and not with his decision to inject more of his activism into what he's releasing. I think that, with few exceptions, musical creativity has a best before date for most artists and their work tends to get repetitive and stale as they age. Album number four in this lot is "The Very Best Of Kenny Rogers And The First Edition". I like everything on this one, but especially "Something's Burning". These might strike you as a pretty boring, safe, run-of-the-mill start and obvious for an older guy like me, but one has to start somewhere. When I was younger I went through a phase where I thought that showing that I'm interested in offbeat, less commercial or obscure stuff would make me seem more hip, sophisticated and mysterious. My contrarian nature bleeding in, if everyone liked it that meant that I shouldn't. Luckily, as far as music is concerned, this period didn't last long. I like the music I grew up listening to and really didn't go out of my way to find much that wasn't popular at the time. Not that there was the kind of opportunity that exists today with the internet; I was limited to what was available at the time on TV, radio and at the record store. And since I grew up during the 70's and 80's, the popular stuff was actually really good. That's not me saying I only like older music - I like anything that's good and appeals to me. But the music I listened to while growing up has memories attached, both good and bad, and that makes for a deeper attachment. I mention recording quality in the video and say that all four of these sound great. I did that because one especially glaring change that an acoustically treated listening room brings is the ability to hear how bad some records are. Stuff that can't be heard well in an average room really shows up when you take away a lot of what the room is adding in with resonances and reflections. How the music is mixed, compression, dynamic range and frequency range are all easy to hear in a treated room.
More on my sins from earlier days and how I let a pretty good music library go to the dogs. I've always been a music lover, but up until recently I took a very casual approach to how I listened to it and how I treated it. CDs here, there and everywhere - in and out of the case, laying on a shelf with a layer of dust accumulating or lodged among the cords and cables behind the stereo. I'd have music playing in the background on any old thing that could squawk it out and be perfectly happy. And while I love making what could be considered high end audio equipment, it was always more about that - making it - than about using it to play music. The means justified the ends, in other words. That changed as I got older and I became frustrated with trying to hear music as I had before, and not getting any satisfaction from it. So I started actually listening instead of having it running while I distracted myself with other things. That's when I decided to build a dedicated room to get the most out of the experience. Now I sit and listen and do just that. I've completely stopped having music playing while I'm doing something else. Very much like anything else I do for entertainment, like reading and watching a movie - they get my full attention.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caTransmission Line Speakers are a TrapJohn Heisz - Speakers and Audio Projects2022-12-29 | A pure transmission line speaker will completely absorb the back-wave from the driver, making it behave like an infinite baffle. The advantage an infinite baffle gives is that there's no cancellation from the output from the front of the driver and the output from the back of the driver. The output from the back is thrown away and only the output from the front is used. In reality, this is almost impossible to do fully, and that's especially true where a speaker box is concerned. You'll never be able to absorb 100% of the back-wave (with current tech), so a compromise is reached in the "transmission line" speaker by using some of the back-wave energy for the overall output. This is done by making the pipe length, damping and taper so that it channels the back-wave out and it is now in phase with the front-wave. This extra energy adds to the front-wave, boosting output. The pipe is tuned so that by the time the back-wave travels through it, it will have shifted in phase to match the output from the front. And while it seems like it would be relatively easy to do that, designing and constructing a box to hold that pipe is more complex than nearly ever other type of speaker. And in my opinion it's questionable whether the results are better than a much less complex (and typically much smaller) ported box. But even when he know this, that doesn't stop the DIY speaker builder from taking a crack at it. And I have to admit that while thinking about the subject for this video, I find myself drawn to the idea again. The one shown in the video thumbnail was very quickly drawn for this video. It shows the typical implementation of the folded, tapered duct with the output opening on the front. Along with this the duct would have to be stuffed with damping material to tune the response and reduce the ripples the long pipe adds to the response. These ripples extend up throughout the effective frequency range of the driver and can be difficult to get rid of. And I'm not unconvinced that the ripples are not what people like about these speakers - that extra "stuff" that's not there in other designs.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caIs Bigger Really Better? Big VS Small SpeakersJohn Heisz - Speakers and Audio Projects2022-12-20 | Small speakers can get the job done and for most people they are the only option. But size does matter. And I should say up front that I'm talking about 2 channel setups, not home theatre multi-channel systems. Bigger drivers (cone area) will result in lower distortion for the same amount of output. However, most people don't hear or have a problem with the extra distortion that smaller drivers working harder produce. For most that would be an easy trade-off. But if you want the most realistic sound stage possible when you are sitting at a normal distance from the speakers, I don't think you can get that from smaller speakers. Or at least that has been my experience. There's a real difference when a bigger speaker with bigger drivers is making the sound - it's more spread out and harder to localize. A comparison could be the gentle breeze from a large ceiling fan as opposed to what you get from a smaller fan sitting on your desk. Sound isn't the same as airflow, but people tend to think of them in the same way. I have had many different (mostly homemade) speakers and always go back to ones that are bigger. My normal take on a claim like this is to say that perception is clouding judgment, that the bigger speakers sound bigger because I can see they are bigger. And there is some truth to that but I've tried to be as objective as possible. Other specific differences also can play a part, like open baffle instead of a boxed speaker. Or multi-way instead of a 2-way. It's my opinion also that a 3-way or 4-way can almost always present a more complete sound stage than a 2-way. Again, it's about cone size and the area of air that's being moved. A 4-way will use three drivers to do what's done with one driver in a 2-way.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caWhy Vinyl Sounds Warmer (real reasons)John Heisz - Speakers and Audio Projects2022-12-17 | Vinyl is inferior (technically) to digital for the following reasons: - Lower resolution / dynamic range - Higher noise - Limited frequency response - Poorer transient response - Less stereo separation - Equalization / compression needed for the media - Disk wear with each play makes the other problems listed above even worse These factors take away the "crispness" of what you can hear from digital. Kind of like watching a movie on a TV from the 80's as opposed to today on a HD screen. That loss of detail translates to what we perceive as softer or warmer. Of course you can make digital sound like vinyl by reducing the resolution and frequency response, and adding EQ and noise, if that's your preference. But I think the psychological differences are the real division. After all, there hasn't been a move back to standard definition TV over the same period, and people haven't thrown out their refrigerator to replace it with an icebox. Records have that simpler time nostalgia attached, that's true, but the media also has a substantial feel to it - something real that you can hold and take care of. Add to that the album art that's big enough to see and appreciate. They feel valuable, unlike music files stored on a computer or streamed via the internet. And you will be taken more seriously as an audiophile (or music lover) if you have a decent collection of records and quality equipment to play them on. Also the act of selecting, cleaning and putting a record on to play is part of the enjoyment. It takes listening to music from purely consumptive to something you are physically involved in. Something that requires your love and attention. And finally there's the widespread belief that vinyl does sound better. It's like a given at this point. I get it. Like I said, I had started on a path of collecting records and turntables. But I soon realized that you need to be a certain type of person to pursue that long term, and I'm not one.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caIm Not an Audiophile - 9 Reasons WhyJohn Heisz - Speakers and Audio Projects2022-11-26 | Reasons: 1 - I'm rational. This may sound insulting, but if you are totally honest about being an audiophile, it includes a lot of mystical thinking and taking things as facts when there's no evidence to back up the claims. Long and short of it is I don't believe in magic and I also know how prone most people are to self deception. 2 - No vinyl. I had records when I was a kid, because that (and 8 tracks) were all there were available. Then I owned a lot of cassettes. Then I started buying CD's and still buy CD's today, because I can rip them and put the music files onto my computer. For me it's all about enjoying the music and not the ritual of messing around with antique media. Having all of my music on a computer is convenient and I can listen for hours without leaving my chair. 3 - Digital vs analog. It's been proven that digital is superior. It has greater resolution, dynamic range and lower noise than analog media. With digital you are listening to the music instead of listening to the music plus whatever other stuff the analog gear adds to it. Did you know that vinyl recordings are equalized? Most real audiophiles shun equalization but have no qualms at all about the one that's in their phono stage. How accurate is it? 4 - Compressed audio. I've tried to hear a difference between a compressed and uncompressed files and couldn't. Granted, my hearing isn't golden, but I've seen similar tests taken by young people who have excellent hearing and they had difficulty discerning a difference. And a difference is just that - a difference. Is one clearly better? If you think it must sound better because it has more information (bigger file), then why do you so enjoy your vinyl records? In reality, records are a form of compression. 5 - "Entry level" amps. I've built amplifiers and I know how they work. They are supposed to provide a louder version of what they are fed, without changing it significantly. So all competently made amplifiers will "sound" exactly the same, unless they are distorting (equalizing) the music in some way. If you want an amp that equalizes the music you are listening to, why not just buy a cheaper (but perfectly accurate) amp and use an equalizer? Be honest about it! 6 - DSP. Digital signal processing. This goes back to the analog vs digital debate and is pretty much self explanatory from an audiophile perspective. 7 - No tube equipment. Again, an antique technology that really should have died out many years ago. Modern solid state can do everything and can even be made to sound identical to the distortion mills that tube amps are. Once more, if you want to EQ your music why not just be honest about it and get a good quality equalizer and do it. Better yet, use DSP. 8 - Cables and interconnects. If they are making a real difference that you can hear, then they are actually degrading the signal. And that includes audiophile quality power cords as well. 9 - Room treatment. Some audiophiles are slowly coming around to the reality that the single biggest factor that affects what we hear (other than our ears / brain) is the room. Room treatment has been showing up over the last few years in rooms where it never was before. And that's a good thing. Most are still not convinced and will spend thousands (seriously!) on a new power cord or ridiculous power conditioner while listening in what amounts to an echo chamber. When your room is untreated, half (or more) of what you are hearing is the room. Better speakers, gear and cabling won't fix that, only properly done room treatment will. And the best part is it allows you to endlessly tinker, if you are so inclined. You can add as much or as little as you like to "tune" the room to sound the way you want it to.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caSuper Tweeters Suck... Heres WhyJohn Heisz - Speakers and Audio Projects2022-08-18 | Comb filtering happens when you have two drivers (speakers) playing the same signal and the signal from one of those drivers reaches your ear before the other one. Depending on the delay time, some frequencies are reinforced while others will cancel out, making the frequency response look like a comb with teeth (peaks and dips). This is a very audible (and proven to be audible) effect.
So while the super tweeter can give a substantial boost to the high end response, it can also degrade the midrange response. And our hearing is most sensitive to these midrange frequencies.
Not shown in this video is how much worse the response can become when listening off axis, especially vertically. As you move above or below the speaker's tweeter, the delay increases, causing more of that comb filtering effect.
Getting the super tweeter as physically close to the speaker's tweeter as possible and using a higher order filter (crossover) will help to mitigate these unwanted effects. But a better "fix" for a perceived lack of high frequency detail is to either crank up the treble knob (if your setup has one) or get yourself fitted with hearing aids. Believe it or not, hearing aids will make a massive difference if your hearing has degraded due to age or damage. And it's a difference that you can't match by boosting the high frequency response of your speakers or by adding a super tweeter.
Website: ibuildit.ca Facebook: facebook.com/I-Build-It-258048014240900 Instagram: instagram.com/i_build_it.caTime / Phase Aligning My Speakers / Subs with REWJohn Heisz - Speakers and Audio Projects2022-08-15 | Up front: I'm not anything like an expert on this and this is just me showing how I used the alignment tool feature in REW along with an interesting way to set the timing reference for an all digital system like I have. If you can see problems with what I did (other than the one where I forgot to move the cursor back to 300Hz to do the phase alignment) then please feel free to say so in the comments.
Time alignment has never been a priority for me, since the speakers I've made in the past have always been "close enough" physically for it not to be a concern. And phase alignment with a subwoofer always shows in the frequency response, so I've taken care of that there.
With that said I thought I'd try to "nail" the timing and compare that to the setup that was just tuned by the frequency response without any delays added. The beauty of the DSP is that I can set different configurations and quickly switch back and forth to listen and decide if there is a difference. Another disclaimer: my hearing is well past it's best before date and while I do wear hearing aids that help fill in what's been lost, I don't have golden ears. In all cases I heard a difference, but can't say with certainty that the difference I heard was due to timing or small differences in the frequency response. And I can't say that one sounded best, or even better than the others. They sounded different - that's all. And within a few hours of listening to a new configuration, my ears (or more precisely my brain) got used to the sound. I'll add that everything I tried sounded great. The differences were subtle and in all instances I aimed for the most even frequency response I could get.
As I pointed out above, I made a mistake while filming this. I failed to move the cursor back to the 300Hz crossover point before hitting the "align phase at cursor" button. But even then the final results STILL sounded great! I later redid the whole thing again just for peace of mind sake. And it's my opinion (you may disagree) that doing these little tweaks are valuable for just that: peace of mind. I don't think time alignment on a single baffle is make or break thing. I think phase alignment is important, but like I said above, any major phase problems will show up in the measured frequency response.
I'll say it again: I'm not an expert or pretending to be one. I know quite a lot about designing and building loudspeakers, but I'm also aware of how much I DON'T know. Admitting I don't know it all shouldn't be taken as proof that you know more than me. You may, and the best way to show that is to be politely helpful. If you have tips and advice, think about how YOU would like to be told them. Also realize that I'm first and foremost a practical man. I recognize factors that are genuinely important and pay a lot less attention to ones that are of marginal value. Time alignment is one of those marginal factors. We do it because we can and for peace of mind, but shouldn't expect miracles as a result. Perfection only exists in the minds of those who have never tried to produce it.