Anyone built a subwoofer into their stage? I've often read of folks filling the interior of their stage/proscenium with sand and then placing their subwoofer on the stage. The sand used to kill any resonance. I'm strongly considering building a DIY Subwoofer into my proscenium (and NOT filling it with sand ) The Fed-Ex guy just delivered a new Ascendant Audio Avalanche 18" driver and my wife had asked when I initally ordered it if I could build it into our stage/proscenium. I said "sure, but the stage will have to be a bit bigger to accomodate it" New Avalanche 18" Driver The approximate external dimensions of the new proscenium-sub will be 15" high, 96" wide, and 36" deep at its center tapering to 28" deep at the ends. This gives me quite a large amount of internal volume to work with. I plan on a lot of internal bracing so I'm planning on building it as two halves. I'll bolt the two halves together once it is in place in the theater. (It would be too heavy to handle myself otherwise) I was originally thinking of a ported sub tuned to 12Hz, but in doing the following rendering, I think it might be easier to make it a sealed sub and use two drivers. I'll make the final decision later. Fortunatly, the same volume enclosure would work in both a "single driver ported" or "dual driver sealed" alignments according to the samples shown on the Ascendant Audio web-site. I use a BFD equalizer, so I can handle just about any resulting frequency response. I'm a beginner at 3D rendering, but this should give you an idea of what I'm planning. The drivers will be mounted downfiring attached to sloped baffles. Ideas, comments, suggestions anyone? (as I get started) I'm off to buy some plywood and MDF. Joe L.