This used to be a 'monitor' wedge. I think it was originally made by Squier/Fender. It consisted of a driver and a horn piezo junk tweeter. The hole for the driver appears to be ~10.75".
Do you think I could drop a bass woofer in there, seal the tweeter hole and use it for a practice bass cab? I don't need it to sound awesome, just usable for band rehearsal.
Any other info you want? I can get inner volume, but it'll take a bit of time/math.