Quote Originally Posted by JSE
Actually, THX is more than just a ceritfication. It's actual sound mode on some receivers just like DTS, PLII, etc.

JSE
I realize that some pre amps / receivers do have a THX mode. I agree with your experience with THX modes, all it does is roll off the highs. But from what I have seen, a majority just carry the logo with no THX mode. I believe I have even seen speakers with THX certification