normal music listening is an added condition. and even with something as unclear as "normal", it's a big one. another one could be a CD that wasn't mastered by a moron trying to prove a point. maybe we could also push toward DACs and restrict the claim to stuff that will not have a ****load of aliasing because the designer never understood how digital audio works. luckily those are becoming rare nowadays, but they surely still are owned by someone on the forum. same with treble roll off, we probably shouldn't have to bother with that, but some audio devices do roll off the trebles in a way that at least a youngster will easily notice at 44.1kHz. me, you and bigshot consider such devices as flawed, but others absolutely love them. also, perfect is a heavy word. I wouldn't use it for anything in real life application except perhaps to lie to a pretty girl. a claim is a claim, our job isn't to say that we agree when we more or less do. everybody already does that on the web. our "job" as casual science wannabe club is to apply the scientific method and try to disprove things. which I can with bigshot's statement as it is. of course I'll have to manufacture conditions for that to happen because I don't purchase weirdo designs and I don't have the years I once had, but the fact that I can disprove the claim if I work on it, means it is wrong.