The sound profile is dependent on the manufacturer. The OS doesn't have much to do with it, so if its too low for you on JB, ICS will be the same. I have yet to find a good app that truly increases the volume of the speakers.
I have a few devices that are too low for my liking as well, so I've tried most apps in the market to no avail.
Equalizer app from the play store helps with volume a lot. Adjust the eq setting to your liking. Try putting all the sliders to max. Sometime flat is flat or heavy metal are best. I've used it on many different devices and it helps every time.