I have found some good information from this community, so first a thanks! (I posted in A-L Users Community first - but this is where the "Altec" action is, apparently.)

I have (2) Altec 421-8H drivers that came in an unsatisfactory enclosure. My interest is to install in appropriate enclosures for bass guitar and LF for theremin, and miscellaneous LF instrument support.

The box they came in rattles and hums badly. It sounds best with the back removed. My goal was to make an 816, or 817. Then, I found a couple of vintage Carvin combination enclosures for 15" speakers. They are rough, no drivers, handles or terminals, but can be obtained more easily than making new. Dims (outside): 28" w x 31.5" t x 24" d

As close as they are to the Altec combination designs (825, 816) I'm thinking they should be worth trying. Any comments are much appreciated.

Thanks, David