I have had a CSi5 paired with RTi8's for about 2 years and have loved them. Recently, I bought a blu ray and started noticing a that voices seemed to be sounding a little muffled. I recalibrated and noticed that during the test tones the CSi5 sounded a little different than the RTi8's. I am a little paranoid about the tweeters since I blew one on my old Monitor 60's so I put my ear to each tweeter. The CSi5's tweeter is definately working but is much quiter than the RTi8's. There is no crackling or anything like that just lower volume. I swapped the wires and the speakers sounded the same reversed. I thought the tweeter was gone so I had Polk send me a new one (great customer service :)). After installing the new tweeter it sounded exactly the same as the old one. I am wondering if the CSi5 is supposed to sound different than the RTi8 or if there is maybe a problem with the crossover. I have checked the binding posts and they are secure.