Very low volume when headphone is connected to my Macbook pro, even if at max. Headphone works correctly on my iphone and other devices. Tried Audio MIDI setup, settings seem to be correct 44.1KHz 2ch-16 bit. Can anyone help me?
In audio Midi setup, change the "2ch-16bit" setting that you mentioned to either the 32 or 24bit option. The hissing should then be gone.
I had the same problem, but it fixed itself when I just simply restarted my macbook. Hope this helps!