I think I'm losing my mind. Today, while listening to my recently-purchased pair of main speakers, I got the sense that the music was slightly harsh, too bright. Having the afternoon free, I pulled out my SPL meter and test tone CD and started working on some measurements and small adjustments (tone controls, speaker placement, etc). The problem is, the more adjustments I made, the worse things sounded. Eventually I just gave up and put everything back the way it was. But now it doesn't sound right at all! Now it feels like there's something missing, mostly in the high frequency end. Before all this I had been thinking that the high end was too harsh and now it sounds too restrained. There seems to be an overall lack of presence and diminished stereo imaging that was there before. Even DD and DTS soundtracks sound "thinner". Again, I put everything back the way it was but it doesn't sound the same. But I'm not sure. The difference may be subtle enough that I'm just not remembering the original sound. Can test tones damage speakers? I never went over 75dB on the SPL meter while using them. Was it just from tweaking so much, hearing so many different sounds, that now I can't remember what the original sound was, and nothing sounds right? This is really bugging me. Anyone out there have any experiences like this? Is it just my confused ears or is something really wrong?