Originally posted by Technodigifreak
cubes, have real problems with resonation and the creation of standing waves, both are BAD if you have a loose trunk with rattleing problems
While it's true that the ideal speaker enclosure has no parallel sides - you generally are not going to see standing waves in car audio in a subwoofer enclosure.
Originally posted by JL Audio
Enclosure Shape
While it is always a pretty good idea to stay away from perfect cubes, they don't necessarily have to be avoided like The Plague. Due to the very small dimensions of most mobile subwoofer enclosures, there is little chance of generating standing waves in the enclosure (standing waves cause nasty response fluctuations). For a standing wave to exist, the distance between parallel boundaries must be 1/2 the wavelength of the frequency at which the standing wave exists. Considering that sub-bass waves vary from 56.4 feet (20 Hz) to 11.28 feet (100 Hz), the generation of a standing wave is going to be impossible....after all, the enclosures we're speaking of have to fit in the average sedan or hatchback!
Besides that point, your car is going to rattle no matter what enclosure shape you have....either a sphere or a cube...doesn't matter.