What you noticed are the effects of psychacoustics, and nothing more! In other words your "I noticed a big difference because I said so" has no merit without scientific evidence to back it up.
RTA proof?
AC or Termlab before and after?
Those are just rhetorical questions because I already know your answer is "NO!"
QFT!
Hell, I once played a trick on a friend of mine. I made him wait in my house while I was changing out his amp to let him use one of mine. He got back in his car and said "Man this sounds so much better and hits so much harder!" The look on his face was priceless when I showed him that he was running his SAME amplifier.//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif