Any suggestions would be greatly appreciated. I have an Infinity PS12 sub, and a Yamaha RX-V2500 receiver. Basically, I've had a very hard time getting my sub to produce bass. I'm not really sure what the problem is. There are times when the sub doesn't seem to be generating any bass whatsoever, even when it should be. There are times when I hear a strange beep/chirp sound come from it. I run the YPAO auto setup program on the receiver, and when it sends the test signals to the speakers, the sub barely makes any sound whatsoever. Two or three times during these setup tests, it's produced more sound, but usually it's a rather weak sound. There are times when I'm playing a movie that I go to check the sub and the red "standby" light is on, as though the sub isn't getting a signal from the receiver. The instructions for the sub say that if the receiver has a LFE connection, then you're supposed to set the receiver to "LFE", and that in this mode the crossover dial has no effect. I've experimented with room placement, it doesn't seem to make any difference. I've tried playing CD's that have a lot of bass, and it just sits there doing nothing. I've wondered whether my expectations were off - I was expecting a ton of window-rattling bass. But the performance of this sub has been underwhelming to say the least. I've considered that it's a problem with the receiver calibration. I've tried running the auto YPAO setup program, and also tried setting up the speakers manually. It doesn't seem to make a difference. I'd hate for the sub to be defective, but from the day I bought it I've never thought that it's produced the kind of sound I thought it would. Could the connections on the sub be loose, or not connecting properly in some way? Does anyone have any thoughts?