Is it possible to set per-application volume levels under Mac OS X?
I would like to be able to turn the volume down on Entourage for new emails, but leave everything else at a pleasant level, adjusting media playback volumes via iTunes or the DVD app.
This is not possible (like linux does) under OS X. However, there are a few alternatives you can try. One would be to reroute certain apps to “null” so you don’t hear them, or another sound output that has a lower level. All this is possible with Jack, a small free utility.
What I did was basically open the New Mail sound file with an audio editor, and drastically lower its level. :) (Yeah, it’s lame but it works!)
Although it doesn't work in Snow Leopard there's a nice open source app, BackgroundMusic, which provides for per application volume control in OSX10.10+:
Jack is a downloadable and free software that enables this feature. Originally written for Linux, it is now available for Mac.
You can do this with Hear. Its not free but it does have a demo. Flip over to the Equilizer tab and you can use a slider to tame the volume per-application.
I was just wondering this same wonder. With the help of this thread I remembered I already had an "app mixer" and tried that, it works great.
"Audio Hijack Pro"
–I initially got it to boost the volume on a laptop but since then I have used it for many projects. It's great for ripping audio from the source (pre speaker) and AS OF TODAY I use it to turn down Premier Pro while editing so I can listen to music without fear of forgetting to readjust settings in my project :)
It's available here with a free trial version:
Sound Bunny (Prosoft, $10) will do it. Unfortunately it does not allow you to select the output interface per application, like Detour did; only the volume. Detour does not work on Intel Macs.
I also found Sound Control by Static Z Software. I've personally not used it so YMMV.
