No... now I realize that I should have.
I don't think it will make much difference. Those Klipsch sub amps are total junk and worthless. You are about the fourth report here of this, so I have spent considerable time researching it. It seems the failure rate of all Klipsch sub amps is 10% within the warranty period, and even higher shortly after. There are quite a few reports of replacement amps failing within months. So it is a waste of time even talking to Klipsch and replacing the amp, which they probably won't as they try and get out of honoring their warranty whenever possible.
I did manage to dig up the circuit for your amp and its garbage. Switching power supplies in sub amps are trouble devices as a class. This one is cynical. The whole concept is designed to hide the fact that they are actually trying to get away with a low powered device without it seeming like it.
Basically the power supply continuously varies voltage to input demand as the output devices won't take power for long. There is heavy use of a gated compressor/limiter, to control dynamic range and peaks, and I suspect this is more output stage protection, and an attempt to protect what is not actually a not very well made or robust driver.
I would say under the circumstances you have these options.
1). Drop it off at the recycling center. Then purchase a much higher quality sub, or better build one.
2). Leave the current amp in place and buy an external amp. This will require connecting the sub driver directly to a set of terminals you mount on the back.
3) Buy a higher quality plate amp and modify the box to take it. You must seal it well.
For option 2 and 3 you will need to be careful how much you put the pedal to the metal so to speak. This is because there will no longer be the gated compressor limiter, and so the driver might wilt.
It seems like option 2 is what most people choose to do who want to salvage the sub, with 3 close behind.
It seems these problems have surfaced relatively recently. My suspicion would be that it is connected to Klipsch being bought by the junk brand Audiovox.
