Static Z Software has released Sound Control, a sound volume mixer for the Mac. It enables users to quickly change app volumes, as well as selectively apply a system-wide EQ to app audio.
Sound Control does this by adding a software mixer to the menu bar of your Mac. In addition to the volume mixer, Sound Control also adds a software EQ to your audio output allowing you to tailor the sound of your Mac’s audio to their specific taste or to properly calibrate to the frequency response of their speakers.
A demo of Sound Control requires Mac OS X 10.9 or higher, and costs $9. A demo can be found at Static Z Software online (http://staticz.com/soundcontrol).