Hello All. I have an old Acoustic 370 bass power head. I don't know how old it is. When I hook it up to an Avatar CB115H and turn the power on, you can see the speaker flex, and hear a "whoomp" sound. Then at any volume over 3, the speaker sounds like it's going to blow apart. The cab sounds great hooked up to the Peavey TNT 115, so I believe it's the 370's fault. Does anyone know of anywhere that will redo this amp? I'd like to get it in good working order and keep as a backup if nothing else. Plus it should be pretty loud when it's working right. I would need to send it off thru UPS or FedEx, as there isn't a local repair shop in my area. Or I could drive to the San Fran bay area. Does anyone know of an honest shop that could troubleshoot and fix this thing? Thanks much.