John Heisz - Speakers and Audio Projects | A Better way to Measure Panel Resonance... Maybe @IBuildIt | Uploaded 2 years ago | Updated 9 hours ago
If you don't understand what I mean when I say "offset", you need to watch the video I made before this that shows the problem and why there is an offset:
youtu.be/xHY45RmAbDc
I think this is a lot more accurate than the method I used in that first video. Using the 100hz tone as a control means I can more precisely calculate the offset between the accelerometer and the microphone. But there are other variables that will make a difference, like the distance the mic is from the speaker. So that offset only applies to this test, and will almost certainly be different for another speaker.
Also, the accelerometer is measuring how much the entire box is moving, along with how much the panel it's attached to is vibrating. So that's another variable that will change from speaker to speaker.
One obvious conclusion I reached while doing this is that resonances up higher in frequency will be much easier to hear. Our hearing is also more sensitive in the midrange frequencies, so you'd want to do what you can to try to prevent the panels from vibrating excessively. Using the right thickness plywood or MDF, bracing and damping is all that's needed to drive down the audibility of these panel vibrations. No need to go to extreme lengths or use exotic materials to build the cabinet, when there like won't be audible gains over a normally well built box.
The speaker in this video is made from cheap 3/8" spruce sheathing plywood. It has big unbraced panels and very little damping. So it's probably an example of the worst case.
Still, thousands of speakers have been made in a similar way by big speaker manufacturers over the last 40 years. Most people would enjoy the heck out of the ones I have here and not hear any problems with the way they sound.
Also an important point that I show in the other video is how much the wall beside the speaker vibrates - it was about the same as the panels in the Elac speaker. So unless you are going to do the same thing with the walls, floor and ceiling of the room you listen in as you do with the speakers, there's no getting away from some amount of panel vibration.
You can help support the work I do in making these videos:
Project plans for sale: ibuildit.ca/plans
Join the ibuildit community on Loacals: ibuildit.locals.com
Support this channel on Patreon:
patreon.com/user?u=865843&ty=h
#diyspeakers
#johnheisz
#audio
My "Scrap bin" channel:
youtube.com/c/IBuildItScrapBin
My main channel:
youtube.com/user/jpheisz
Website: ibuildit.ca
Facebook: facebook.com/I-Build-It-258048014240900
Instagram: instagram.com/i_build_it.ca
If you don't understand what I mean when I say "offset", you need to watch the video I made before this that shows the problem and why there is an offset:
youtu.be/xHY45RmAbDc
I think this is a lot more accurate than the method I used in that first video. Using the 100hz tone as a control means I can more precisely calculate the offset between the accelerometer and the microphone. But there are other variables that will make a difference, like the distance the mic is from the speaker. So that offset only applies to this test, and will almost certainly be different for another speaker.
Also, the accelerometer is measuring how much the entire box is moving, along with how much the panel it's attached to is vibrating. So that's another variable that will change from speaker to speaker.
One obvious conclusion I reached while doing this is that resonances up higher in frequency will be much easier to hear. Our hearing is also more sensitive in the midrange frequencies, so you'd want to do what you can to try to prevent the panels from vibrating excessively. Using the right thickness plywood or MDF, bracing and damping is all that's needed to drive down the audibility of these panel vibrations. No need to go to extreme lengths or use exotic materials to build the cabinet, when there like won't be audible gains over a normally well built box.
The speaker in this video is made from cheap 3/8" spruce sheathing plywood. It has big unbraced panels and very little damping. So it's probably an example of the worst case.
Still, thousands of speakers have been made in a similar way by big speaker manufacturers over the last 40 years. Most people would enjoy the heck out of the ones I have here and not hear any problems with the way they sound.
Also an important point that I show in the other video is how much the wall beside the speaker vibrates - it was about the same as the panels in the Elac speaker. So unless you are going to do the same thing with the walls, floor and ceiling of the room you listen in as you do with the speakers, there's no getting away from some amount of panel vibration.
You can help support the work I do in making these videos:
Project plans for sale: ibuildit.ca/plans
Join the ibuildit community on Loacals: ibuildit.locals.com
Support this channel on Patreon:
patreon.com/user?u=865843&ty=h
#diyspeakers
#johnheisz
#audio
My "Scrap bin" channel:
youtube.com/c/IBuildItScrapBin
My main channel:
youtube.com/user/jpheisz
Website: ibuildit.ca
Facebook: facebook.com/I-Build-It-258048014240900
Instagram: instagram.com/i_build_it.ca
