Oval room for a home theater? No thanks. A parabola or an ellipse will focus acoustic energy... This is a very bad idea for a home theater. There's a big difference between a room designed for natural acoustics and a room designed for amplified sound. In terms of eliminating standing waves before room treatment, you do want to avoid parallel surfaces. If you really need a symmetrical space, a fan-shaped room will work, but it also requires creating some unusable space. However, a larger rectangular room with "proper" room treatment will work just fine.
OdinGOW, I would suggest that you consider answering Andrew's questions above. That will allow for more accurate advice to be given.
Last edited by Yubbie; 10-06-2014 at 11:19 PM.