I have a 970 and a 7500 and a pair of Monitor Audio Speakers. I was listening loud one night and I lost one speaker. I thought that was the problem. I got a new crossover and it made no difference because the other channel went out. So I listened to the middle channel. Now it has gone out.

Is it the preamp or the amp. I don't want to pay shipping for the wrong one.

You may have already done this, but I'd suggest the following tests.

Let's say the left speaker is out. I'd try a couple of tests. First, I'd connect that speaker to a different channel on the amp (left surround channel, for example). Make sure the channel in question is hooked up and turned on at the 970, then play something (a test tone will do) that uses that channel. If you get sound from the speaker when it's on the left surround channel, I'd move the left pre-amp output from the amp's left channel to the left surround channel (which the speaker is still connected to) and try playing something again. That will test all of your variables: pre-amp output, amp channel, and speaker.

Also, take a good close look at your speaker wiring - make sure no strands have gotten loose and you're not shorting the positive and negative leads together at either the amp or the speaker.

Thanks, but I tried that. It's the strangest thing. It's like amps or channels are just fading away.

Prodman,

That is an interesting dilemma!

The obvious test are:

Speakers:
1) Swapping dead speaker to alternate channel to see if works?
2) Swapping working speaker to dead channel to see if works?

Pre-amp:
1) Swapping dead pre out to alternate amp channel to see if works?
2) Swapping working pre out to dead amp channel to see if it works?

Have you tried all? Results?

As for the speakers, you mention the swapping of crossover . . . I build speakers as a hobby and unless there is a MAJOR design flaw with the speakers, or really really cheap parts, the crossovers should not blow. Possibly drivers will go from a clipping amp (most common cause). A simple 1st order crossover design might use 3 crossover components (inductor on woofer, capacitor / resistor on tweeter). A second order will use minimum 5 Components (inductor/capacitor on woofer, capacitor/inductor/ resistor on tweeter). As the design gets more complicated, the parts list goes up . . . usually a dead crossover component results in either the loss of the tweeter or mid woofer. If your speaker went completely dead, it is most likely a fuse they built into speaker cutting off all power. When you repaired the first speaker, did Monitor Audio confirm the fault? BTW: Is your center channel a different brand / Model?

The symptoms tend to lean towards a faulty amp. It is not likely to blow three speakers . . . unless you play so loud that the 7500 has hit its natural clipping point. If so you’re going to go deaf soon anyway and your speakers dying is probably a good thing (haha).

We were playing awfully load........but the center channel is a different brand (Klipsch).

We'll try your suggestions.

Sorry meant loud.