I have 2 sub25's less than 3 years old, and both bottom out now. I am using an older pioneer receiver, vsx-01txh. I watch movies at -20db, sub output set to -4, and sub25 less than half way and it clanks on every movie when low bass hits. I am sending one in now, hopefully will still be under warranty. Paradigm is very slow at fixing things, it's been 3 weeks and still no answer, just beware of that if u buy there products, very hard to get fixed. I will then send my other sub in when and if I ever get it back. My dealer thinks it is the amplifier, but had him send both the amplifier plate and subwoofer in. The woofer does have a slight crack forming around the speaker about 6 inches long. They told my dealer that they don't make those woofers anymore and would probably have to recone the woofer, price is $650, if not covered by warranty, that sucks. I think they should have the woofers in stock, it's not even that old, what kind of company is this? Has anyone had these problems like I have. I am not to happy with paradigm products at the moment. So anyone buying one of these used, just be careful and know that there are problems with these subwoofers. I hope I can get mine fixed. Please tell me if anyone has experienced these problems.