recently moved house and when I put the hifi back together I noticed that the tweeters in my Quad Q11Ls had gone very quiet and tinny sounding. Bought new speakers and same thing! It would appear to be my amp that is at fault but is it the tweeters or crossovers that are damaged? as I said, you can hear the music but it's horrible.....any advice appreciated (the bottom end is fine by the way...)