Re: Bass through guitar tube amp?
So it seems most people think it would be ok except for the speakers?
Well, sure...the general concensus is that for the short-term you're unlikely to do damage by using it at a lower volume.
However, it sounding like a sack of smashed *******s is something entirely different.
The thing I always envision when folks ask about these things is having to explain to a repair tech exactly what the amp was being used for when it just "stopped working." Especially if you're looking at things like a warranty.
For a few hunded bucks you can get something like a used Peavey Mark IV head; there's a slew of headroom on them and they get loud...VERY loud. There's also a GK 800RB: 400 watts and it'll swamp any drummer thinking he needs to flex his muscles.
Find a decent cab, something that's dependable and used. If you say Behrininger then I'll know you're not being serious. Look at some of the odler Hartke stuff that the purists poo-poo. It is what it is, but it will also do a fantastic job of holding up and working forever. I've seen SWR 4 x 12's for a few bills, Trace Elliot as well.
If you're serious about doing this then get the right tool for the job or don't bother doing the job at all. You'll just look like a clown showing up with a guitar amp for it.