I'm not certain if it is compatible (although I don't see why it wouldn't be), but I would try Voodoo Control? Worth a shot - would need to get the paid version, but the headphone jack improvements are worth it.
Like max it out and then run it down and back up again?
If the problem is the same as I had them all you need to do is turn the volume down one notch and then back up. When I was on ICS the volume would be very quite until I did this. And it seemed to happen after each time I booted the phone.
EDIT: Used the VooDoo control app and what a difference! Worth every penny!
Yeah - apparently the Samsung used nice hardware for the headphone amp etc, but their software/kernels didn't take advantage. Supercurio is a madman obsessed with audio fidelity and it really unlocks the potential of our phones. Makes me feel back when I use my bluetooth headphones, but it's great when I jack into my speakers at home.