Amp output drops at high volumes

[Loper23]

I have 2 Pioneer GM-8601 amps paired with 2 Pioneer TS-W3002D2 subs, both wired down to 1 ohm. I am using them in a single chamber ported enclosure tuned at 33hz. I tuned both amps with a DMM to match them exactly. The amps are daisy-chained together.

They have worked great for about 7 months. A few days ago, I was driving back from my friend's house when one sub stopped playing. I had blown the fuse for the power wire running the amp. I got a new fuse. When I installed the new fuse, it started playing again, but cut in and out when I turned the volume up. Sometimes it cut out entirely, sometimes it just had really weak output. It played entirely normal (matched the second amp) as long as I kept the volume low. It's not going into protect mode. The power light stays blue the entire time. Voltage isn't dropping too low.

I have checked all fuses, wires, connections, etc. I have connected the RCA's directly to this amp, as opposed to running this one off the output RCA's of my other amp. Same effect. The other amp still plays normal even when ran off the "bad" amp's output. I have turned the subwoofer output level down on the radio (Pioneer) from +6 to -6 and it still cuts off around the same volume (~37). I just finished disassembling and reassembling the amp. I didn't see any visibly damaged components on the inside. I'm gonna try hooking it up again tomorrow in a different setup.

Anybody have any suggestions as to what I could try??

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[Jepalan]

There is a reason the fuse blew in the first place. It is likely because one of the sub's is failing (voice coil burning out). Get a DMM, disconnect the suspect sub and measure the resistance of the voice coil(s). Post your results here.

 

[Loper23]

I wasn't able to check it with my DMM. For some reason my DMM cuts off when I turn it to the 2 lowest ohm settings. ?? It works fine on everything else. Anyways, the sub was bad. I wasn't able to tell it was rattling until I removed it and played it free-air at low volume. Plus it smelled of burned voice coil. A took the sub apart, and sure enough, the voice coil was roasted. I believe the amp is fine, though I haven't had a chance to test it.

Thanks for the help.