Same as everyone else said, try swapping cables, instrument or speaker, with known good ones, try another bass if you can.
Always check the cheap stuff first!
If that doesn't work, make sure bass is passive, no battery.
If you're still getting it, either get another head or speaker, or both, and try different combinations. The bad stuff should move with the damaged component, if the head's good, it'll sound good with the borrowed speaker. If the speakers good, it'll sound good with the borrowed amp.
Assuming that head puts out more wattage than the cab can handle, at the ohms rating of the speaker, that's usually fine, the extra power lets you handle transients, SHORT bursts without clipping the amp, and the speaker will tolerate more power for a short while, as long as the average power is within the cab limits. You have to turn down when you hear signs of strain on the speakers, or clipping on the amp, do that, and you're fine.
Having said that, if you're running the amp into clipping consistently, its putting out more than the cab can handle long term, it'll burn out eventually.
If you're running a lot of bottom end, you also may have pushed your speakers into overexcursion, and popped the voice coils out of the gap, torn something, and damaged the speaker mechanically. If you gently push on the speaker, and it grinds, that's what happened.
If you hear distortion, something is being pushed beyond its limits, you have to turn down. You either don't have enough cabinet or enough power for the volume you want.
Probably more likely to have damaged the speaker, a 410 is good for most gigging situations, but if you guys are screaming loud, another cab could be needed.
Good luck, hopefully its a cable or something cheap/simple to fix.
Randy
Thank you all for being on TB!
