kyaloz said:
Can someone please show me a pic or drawing of what this looks like. I can understand most of the specs i just don't know the shape of the vent and where the driver goes?
Greets!
I don't do drawings. This is your project, not mine, so I expect you to make whatever notes/sketches is required to fab them. This one is a little more complex than a typical BR, but not much. Visualize a ~84.15" i.d. long rectangular pipe with a smaller rectangular hole in the bottom (the speaker cab) with another ~55" long open ended rectangular pipe attached to it (its vent). Place the driver ~26.55" down from the larger pipe's closed end. Now fold it all up as required to suit your space limitations (if any).
Since this is a sub, ideally you want the driver and vent to be at floor level and perpendicular to it for max boundary gain. Any voids should be filled with something massive so there's no cavity resonances. I prefer kitty litter, but others prefer sterilized sand, Portland cement, fine gravel, etc.. I also recommend using 19mm (min) no-void ply such as 13 ply Baltic Birch, Appleply, or marine grade (if your local supplier has some that's actually void free) to ensure that the cab is rigid enough for its Fs to be well above its intended BW.
Between the CSA's being relatively small and the folding's stiffening effect, no additional bracing is required.
GM