I use an audio interface (namely a Roland Edirol UA-5, but that doesn't matter) which does not support volume control. I can only control the volume with the physical volume dial on the audio interface.
Now, by combining two freewares from RogueAmoeba, Soundflower and LineIn, I am able to enable volume control on any audio interface by:
- Selecting Soundflower as my primary audio interface
- Routing Soundflower to my Edirol UA-5 with LineIn
Thus enabling my native volume to control my audio interface.
This is my question now: is there a native modification I could make to OSX (a flag somewhere, a special kext) that could make this process easier?