Sound better on Windows via bootcamp than on OS X

Hi

I have a non-Retina MacBook Pro mid 2012, and I noticed, that the sound through the internal keyboard speakers is way better under Windows via Bootcamp than on OS X Yosemite. By better I mean more clear, less agressive, probably the woofer is more predominant.
Did anyone else notice the same thing ?
Does anyone have an idea why is that, and how to have the same sound on OS X ?
Thanks