How important is it to have a relatively square shaped encolsure? I know ideally the walls should not be parallel for reflection purposes, but does an oddly(think bubbly fiberglassed) shaped box lose any sound quality, compared to a box with straight, but not parallel walls?

 

rigidity is more important than standing waves and enclosure diffraction with a sub box, those problems are more a concern with bookshelf and floor standing home speaker enclosures