I bought an Ampeg 810e cab two years ago, and it has played amazing for me . Tonight at practice, we noticed a strange noise coming from my cab. It is a crackling , almost dirty pot sounding noise. It doesn’t sound like a farted out speaker . I was playing decently loud, using a Hartke LH1000 in mono. it was just under 3 on the volume . we checked the cables, checked with another bass, and checked with another 810 cab, and determined the noise was , in fact, coming from the 810. it seems to come from the center left speaker , but it’s more in that area than from the speaker for sure . We removed the grille, visually inspected each speaker while playing , everything looked okay. We gently and evenly touched the cones and the outer edges of the speakers to see if we could isolate it, the sound never went away . None of the dust caps look bad, and it looks entirely sealed up. I wasn’t able to dive in and try a bunch of stuff, but I did check all of the screws around each one of the speakers, they were all good and tight. I tried moving the cab and my head to see if it changed anything, it did not . We tried pushing on the wooden cross brace to see if it would stop then noise , and it didn’t . I’m unsure of what to do. I’ve read a lot of threads here, and I have a general idea that it may be a voice coil or cab rattle. any and all help identifying or fixing this is greatly appreciated .