Mac OS X: Reset Volume Balance via Script
I have connected a set of Logitech 2.1 speakers to the headphone/line out port of my 2013 MacBook Pro running OS X Yosemite (10.10).
Whenever I disconnect that connection (to take the MBP with me), return home, and reconnect the cables, the system volume balance seems to have run out of order, i.e., is not set to the center but to either the left or the right loudspeaker channel.
I have yet to find the reason for this behavior but was able to come up with a quick fix. I have put the source code for this solution on GitHub: reset-audio-balance.
Using Automator, you can wrap a script in a “Run as script” action, save it as an application, and add this application to your user’s login items, so the balance will be reset to center on every restart of your Mac.
Update: for your convenience, I have wrapped the script into an app (using Automator) that you can download here{.lizip}.