Alright, i wasn't clear again in my second message i noticed. Basically, i want to put a bass speaker in my guitar amp. Its an old Peavey Encore 65 tube dealy.
Didn't see your earlier post, but right off the top of my head: 1. It will be underpowered to drive bass frequencies. 2. The cabinet isn't designed and tuned for a bass speaker OR bass frequencies, you will likely have overtones all over the place. 3. The EQ controls on the amp are centered on guitar frequencies, they are not voiced for frequencies required of a bass guitar. 4. Don't throw money at it with a new speaker, its a waste, IMO.