Plugging a guitar amp into a bass cabinet: is this wise?

are you going to be amping up a guitar or bass? i use a guitar head in my bass rig occasionally and it works fantastic.

for guitar im not sure but id say try it.

or go for a slightly cheaper guitar head

 

Guitar through a bass speaker should be fine. I don't know how it'll sound though... it's likely to be a bit too clean. Guitar speakers are usually designed with a small X-max but large X-mech... in English they're designed to run out of suspension travel (and therefore distort) pretty early, but they can run at these suspension limits without being physically damaged. You will often hear guitarists talking about the sound and characteristics of their speaker break-up. You probably won't get any of that through a bass cab. And the horn might even make thing sound too bright. And it won't be as loud as a guitar cab for various reasons. But in terms of damage, you shouldn't have any problems. Just don't go crazy with volume.