Apple - How can I limit the headphone max volume on OS X?
I now got a working solution based on one of the links in Michiel's answer, but let's spell it out more clearly.
What I did was to
- Download volimiter, a faceless CLI application.
- Pair it upp with Lingon, a launchdaemon manager.
Set volimiter to launch on login with preferred setting:
volimiter .6
.6 means 60% of volume.
Works terrific!
If you're not satisfied with the default audio settings of your Mac (I can increase or decrease the sound for my whole OS with one key), you can try Hear. It's an equalizer (and limiter) for the sounds your Mac is producing.
If you really want to limit your sound, I'm afraid there is no app for it right now. I found some other topics however where they asked the same question as you. Here and here. Basically, it comes down to "use limited external speakers" or "be aware of your sound settings" :)