Uploaded August 2026 | Updated September 2026, 2 weeks ago
Thanks to Audio46 for the loan of Sierra!
Buy from Audio46 (affiliate link): audio46.com/products/auribus-acoustics-sierra-reference-open-back-headphones?ref=reviewsbywavetheory
Auribus Product Page: auribusacoustics.com/products/sierra-open-monitor
Buy from Apos Audio (affiliate link): https://apos.audio/products/auribus-acoustics-sierra-reference-open-back-headphones
Want to support the channel? Consider becoming a member! Or you can join my Patreon here:
patreon.com/wavetheory1
Or make a 1-time donation through PayPal here:
paypal.com/donate/?hosted_button_id=7N7Z8WRLWQ36E
Follow me on…
Bluesky: https://bsky.app/profile/wavetheorysound.bsky.social
Instagram: instagram.com/wavetheorysound
Test Gear...
All music was digital in lossless or hi-rez FLAC or DSD formats either played locally or streamed from Qobuz (FLAC only), all through Roon.
Chain 1:
Sonore ultraRendu v1.3 (youtu.be/qEOOE9rP6Rs) USB output into Singxer SU-6 DDC (youtu.be/6dr4T0Sd_NU) then I2S into either Ferrum WANDLA GSE & Oor combo (Hypsos power supply, youtu.be/Qh1b-XFH7R8, youtu.be/xUsRyoBPdyk) with Oor's XLR pre out into XLR switch or LAiV Harmony DAC (youtu.be/GtKG5_ABzAg) into XLR switch, then into either Niimbus HPA US5 Pro (youtu.be/lLlPJyvGSIQ) or Cayin HA-300mkiii (review coming!)
Chain 2:
FiiO M33 R2R DAP in Roon mode (youtu.be/byeOH9YPAGc) USB output into Weiss Engineering INT-204 DDC (youtu.be/94AvDeeRjHA) then AES into Schiit Gungnir 2 DAC (youtu.be/XzOPRleWXgE) XLR output into Jensen ISO MAX PC-32X xlr-to-rca transformer then into Schiit Lyr 5 (youtu.be/AL4m9taaMGM)
Chain 3:
Matrix TT-1 streamer/transport (review coming!) USB connection into Weiss Engineering INT-204, then AES into Schiit Gungnir 2, then XLR into Flux M-Field (youtu.be/51VKme4DQig)
Compared Headphones...
Focal Radiance: youtu.be/rXnmlXCf_bA
HFA Dahlia: youtu.be/Cpogn3-hYPg
Mirph Designs MIRPH-1: youtu.be/b7AvyocYck4
Timestamps...
00:00 Intro, Pricing, Disclaimer
02:04 Shameless Self Promotion
02:37 Timestamps! & Takeaways
04:52 About the Sierra Reference & Drivability
12:28 Build & Comfort
14:52 Sound
23:00 The Bass Shelf is Also its Weakness
34:15 Cabling Controversy
35:42 Wrap Up
Thanks to Audio46 for the loan of Sierra!
Buy from Audio46 (affiliate link): audio46.com/products/auribus-acoustics-sierra-reference-open-back-headphones?ref=reviewsbywavetheory
Auribus Product Page: auribusacoustics.com/products/sierra-open-monitor
Buy from Apos Audio (affiliate link): https://apos.audio/products/auribus-acoustics-sierra-reference-open-back-headphones
Want to support the channel? Consider becoming a member! Or you can join my Patreon here:
patreon.com/wavetheory1
Or make a 1-time donation through PayPal here:
paypal.com/donate/?hosted_button_id=7N7Z8WRLWQ36E
Follow me on…
Bluesky: https://bsky.app/profile/wavetheorysound.bsky.social
Instagram: instagram.com/wavetheorysound
Test Gear...
All music was digital in lossless or hi-rez FLAC or DSD formats either played locally or streamed from Qobuz (FLAC only), all through Roon.
Chain 1:
Sonore ultraRendu v1.3 (youtu.be/qEOOE9rP6Rs) USB output into Singxer SU-6 DDC (youtu.be/6dr4T0Sd_NU) then I2S into either Ferrum WANDLA GSE & Oor combo (Hypsos power supply, youtu.be/Qh1b-XFH7R8, youtu.be/xUsRyoBPdyk) with Oor's XLR pre out into XLR switch or LAiV Harmony DAC (youtu.be/GtKG5_ABzAg) into XLR switch, then into either Niimbus HPA US5 Pro (youtu.be/lLlPJyvGSIQ) or Cayin HA-300mkiii (review coming!)
Chain 2:
FiiO M33 R2R DAP in Roon mode (youtu.be/byeOH9YPAGc) USB output into Weiss Engineering INT-204 DDC (youtu.be/94AvDeeRjHA) then AES into Schiit Gungnir 2 DAC (youtu.be/XzOPRleWXgE) XLR output into Jensen ISO MAX PC-32X xlr-to-rca transformer then into Schiit Lyr 5 (youtu.be/AL4m9taaMGM)
Chain 3:
Matrix TT-1 streamer/transport (review coming!) USB connection into Weiss Engineering INT-204, then AES into Schiit Gungnir 2, then XLR into Flux M-Field (youtu.be/51VKme4DQig)
Compared Headphones...
Focal Radiance: youtu.be/rXnmlXCf_bA
HFA Dahlia: youtu.be/Cpogn3-hYPg
Mirph Designs MIRPH-1: youtu.be/b7AvyocYck4
Timestamps...
00:00 Intro, Pricing, Disclaimer
02:04 Shameless Self Promotion
02:37 Timestamps! & Takeaways
04:52 About the Sierra Reference & Drivability
12:28 Build & Comfort
14:52 Sound
23:00 The Bass Shelf is Also its Weakness
34:15 Cabling Controversy
35:42 Wrap Up
