Does the shape of the enclosure matter if the volume stays the same and the distance between the driver and panel are the same also? This would be for a sealed enclosure.
Actually... I'd say for a subwoofer, it matters more (technically).
Standing waves are your enemy, and parallel surfaces (walls of your enclosure) help to create standing waves. The perfect enclosure would have 0 parallel lines.
Is this getting extreme? Yes somewhat... but I've definately noticed differences in my testing over the years.
For true sub reproducing 80Hz and below the wavelength is so large that the enclosure shape will not have any effect, a cube is fine. Now for car subs, that's a different story most go up well above 80Hz. The enclosure shape is most effective in the midrange area, and not just the outside but the inside is equally important as any acoustic energy reflected back to the cone with enough amplitude will distort the drivers movements. Standing waves are easily delt with with batting/polyfill or similer wall lining.
Ok so it's determined that standing waves are not an issue for subs - so why then does more stuffing in a sealed sub effectively increase an enclosures Q? I thought it was because they broke up standing waves?
No, it dissapates some of the energy. As the pressure waves inside the box moves the stuffing strands around it generates some heat, hence energy is dissapated. This reduces the higher frequency output and results in a lower Q alignment.