Amazon.com: USB Live Sound Card, 24 BIT 192KHZ HD USB External Sound Card Digital Audio Mixer Protable Podcast Studio Equipment for Live Stream for OS X for iOS : Electronics
Volume Mixer Alternatives for Mac: Top 4 Volume Control Tools & Similar Apps | AlternativeTo
Easy Audio Mixer im Mac App Store
RPG Audio Mixer - Mac OS X | Brian Kelly | Flickr
How to hook up a USB audio device to your Mac | Cult of Mac
Rogue Amoeba | SoundSource: A Superior Sound Control
Volume Mixer lets you control your Mac's volume, app by app