Yeah,I know, humor me. I saw these at Home depot this morning, and they're made of a thick foam material, about 3/4" thick. The one I saw tapered from 26" at the top down to about 16" or so,21" high. It stated the volume as 88 quarts (I assume "dry", making it about 96 liters), which would be enough for a Shiva using the "Adire" reflex alignment from the Shiva paper. I though that the non-resonant material and the tapered cylinder shape might make for something interesting. Would the properties of a cylinder be preserved when tapered like this? Might it make it more resistant to standing waves? Is there a better 12" to maximise extension in a small bass-reflex?