Angled walls of benefit?

[randix]

I found room dimensions for my track room that fit in my space and have what looks really good to me on the Helmholtz graph. (I used one found at http://bobgolds.com/)

(You can see the dimensions in my floor drawing - Not perfect scale but close.)

What do you think about angling the left TR wall (pink highlight) to 20 degrees?
I retain the same cubic space...
If I also angle the ceiling, I would only have two parallel surfaces (front and back walls).

Would I benefit from this move or do you think I should stay with the basic rectangle? (The Helmholtz curve looks so good, will making the walls angle mess this up?)

Thank you for your thoughts.

Randy