Does Windows 7 perform AVL / limiting?

christopherw · Sep 7, 2011, 03:50 AM

I have a dualboot XP x32 / Win7 x64 setup with my Audigy 2 rocking KX v5.10.00.3550 debug. I've noticed at high volume levels (or multiple concurrent unity gain sources, e.g. a film playing at full volume plus foobar2000 playing a track at full volume simultaneously) Windows 7 appears to duck / regain / auto level the outputted sound. I'm using Wave Out 2/3 as Windows 7's default audio output (to avoid that nasty click bug with Master Mixer as default); I use 2/3 anyway for the higher quality DAC (and just have my outputs inverted in the KX mixer). Headphones are always plugged into 0/1 for gaming / quiet time listening.

There's no audio enhancements enabled (or even available) in Windows 7 and whilst I have a custom DSP setup, nothing in there is set to limit or compress the master output. If I play (for example) a Noisia track and then play a loud rock track over the top, the two sound like they're being brickwall limited together. This doesn't happen in Windows XP with exactly the same driver revision and DSP set (it just gets super loud and peaks above theoretical 0 dB in a Peak monitor!) Has anybody else noticed this odd little occurrence in Windows 7?

Happy to post my DSP if anybody wants to check it out. It's designed for pseudo-mix minusing with Skype - multiple channels used for monitoring and main mix (and mix minused return) and compressed and EQed microphone input - but my main speaker output is an entirely separate, and unprocessed, signal path. It's a headscratcher!

Sep 7, 2011, 03:50 AM	#1
christopherw HardwareHeaven Newbie Join Date: Jan 2004 Posts: 17 Rep Power: 0	Does Windows 7 perform AVL / limiting? I have a dualboot XP x32 / Win7 x64 setup with my Audigy 2 rocking KX v5.10.00.3550 debug. I've noticed at high volume levels (or multiple concurrent unity gain sources, e.g. a film playing at full volume plus foobar2000 playing a track at full volume simultaneously) Windows 7 appears to duck / regain / auto level the outputted sound. I'm using Wave Out 2/3 as Windows 7's default audio output (to avoid that nasty click bug with Master Mixer as default); I use 2/3 anyway for the higher quality DAC (and just have my outputs inverted in the KX mixer). Headphones are always plugged into 0/1 for gaming / quiet time listening. There's no audio enhancements enabled (or even available) in Windows 7 and whilst I have a custom DSP setup, nothing in there is set to limit or compress the master output. If I play (for example) a Noisia track and then play a loud rock track over the top, the two sound like they're being brickwall limited together. This doesn't happen in Windows XP with exactly the same driver revision and DSP set (it just gets super loud and peaks above theoretical 0 dB in a Peak monitor!) Has anybody else noticed this odd little occurrence in Windows 7? Happy to post my DSP if anybody wants to check it out. It's designed for pseudo-mix minusing with Skype - multiple channels used for monitoring and main mix (and mix minused return) and compressed and EQed microphone input - but my main speaker output is an entirely separate, and unprocessed, signal path. It's a headscratcher! __________________ Tickety boo.