[linux-audio-dev] Re: Mixer controls

Do you process each channel with audio software prior mixing? If yes, then I would suggest to fix the hardware levels to the optimum level, and use gains only in software. As FA wrote, soundcards most likely do not have click-free mutes and smooth gains. When the hardware is fixed, you may do faded mutes in software with good quality. Fixing the hardware input and output levels makes sense to me. The input devices all have fixed SNR -- it does not help to crank up the soundcard input level as it brings the noise up. The output would be fixed for the same reasons. Also, fixing the output prevents you accidentally damage the speakers and your ears. When you crank up the gain in software, you may have a software limiter prior the monitor outputs. Once I watched when a friend mastered CDs. The fades were auditioned by cranking up the level on the mixer desk. A couple of times happened that the level was not set back to normal position when needed. :-| By fixing the hardware (including external mixer desk) in the audio path, you may have full control with the software. Soundcards are not optimal for listening fades. Only software gain allows one to audition the fades. With hardware gain the sound can be muddy, but most likely your card cannot make +64 dB gains needed in listening the fades. Cards equipped with an user-programmable dsp chip allows one to move the code from the software to the firmware. I'm in understanding that in SB Live all hardware gains are actually software gains. I.e., they have fixed the hardware. Juhana -- http://music.columbia.edu/mailman/listinfo/linux-graphics-dev for developers of open source graphics software