Thanks Sean and Bob. Yes, this project is important to me. The designer has been very kind to me, and I know he'd get a kick out of having one of his first production designs restored in this manner. And yes Sean, this is an origional pair, and I'm just rebuilding them. The material that was inside the cabinet looks to be fiberglass batting R-19, but it had almost completly disintegrated, so besides the material type, and the fact that it was one piece of batting, it's hard for me to tell what was really there. I'm sure the designer will tweak the system, but I'd like them to sound good when we first fire them up. Either way, I'll take what seems like wise advice from both of you, and try to fine tune the system by ear this weekend. Thanks again. Robert.
Damping material for infinite baffle?
I'm restoring a pair loudspeakers that use a sealed box for the bass driver, and an open baffle for the mid and trebble drivers. I've already changed all the drivers (with factory parts) and repaired the crossovers. But now I'm stuck. What is the theory behind using damping material inside the sealed box? Should it be placed against the inside of the speaker walls to try and absorb the rear wave? Of should it "fill" the cabinet? It is my understanding that the former is the way to do it, the idea being to "fool" the speaker into behaving like it is in a larger box than it actually is. And how much should you use? And what material and thickness works best? (I think that the design calls for fiberglass batting R-19)....I am planing to present these speakers to the designer as a gift, so I don't want to consult with him about the correct way to do it! Too bad I have no idea what I'm doing! Help!.....Robert.