I have a carpeted living room, and my speakers have always sounded a bit muddy.
This weekend I went to Home Depot and bought 2 16x16 ceramic tiles for a grand total of $4 dollars. I put them under the speakers and the difference is truely amazing! It's a far better upgrade than the $100 interconnect or the $200 speaker cables I bought.
I can't believe i didnt try this a couple of years ago!