Not really, but believe what you will.$2000.00 Amp through a $20.00 Chinese knockoff speaker.
It's not a matter of belief, but experience.Not really, but believe what you will.
Most likely it's worn tubes. My Matchless can get a little rubber down there, they tend to put out a lot o flows, perhaps too much for a 1x12. Dial back the bas so it just turns on and adjust everything else so it's not too bright.