I`ve been known to use a friends guitar amp while giging as a bass player..the amp was mic`ed at the venue so i never really had to turn it up very loud..although I have cranked it a bit during practices, but as mentioned above, as long as you do not bounce the cone too far out, your good..LOL
been so long ago now, I really do not even remember what the amp was? I`m thinking it might have been an old fender reverd? can`t remember for sure though..
either way, i never did blow it up while playing my bass through it..but I did put a bit of a hurt`in on it, when it slipped out of my hands and tumbled down a flight of stairs while leaving a gig, ..ouch..LOL
Was at a bar/club in pontiac michigan, thank god no one was on the stairs comming up or down when it happen..LOL
Was a TALL set of stairs let me tell ya!!
EDIT:...just to add..i often record my bass using my ole Crate amp head and a 4X12 guitar/speaker cab...lately I`ve been using my newly aquired GLS ES57 mic, and it does`nt sound half bad with a bit of EQ`ing..