Diaganol Speaker Placement for Small Room

In your case it might actualy be a good idea. Usually I would discourage it. Worth a try.

I have had great results in a slightely smaller room with a diagonal setup. I'm not sure if diagonal setup would ever be a bad thing, maybe if yours speakers put out huge bass. Imaging and bass quality improved dramatically. Highly recommended!
-Vik

i have done a set-up w/ listener facing into a corner and speakers on either side of the corner. this set had positives:
-no early reflections from side walls
-fit the needs of this room
there was one major problem------the corner placement over emphsized the mid and low bass --throwing the balance out of wack. i solved the bass problem throght trial and error
with stacks of rolls of fiberglass 22" in diameter. a stack 8' high in the corner between the speakers did the trick. i made a cover for this huge bass trap so that it almost looked decent.

this set-up created the widest sound stage i ever acheveived with the b&w 802 serIII speakers wich i owned at the time.
i was impossible to maximized the depth of the sound stage w/ this corner set-up. i tried many variations and none worked as well as a symetrical set up alond a long wall for
a deep sound stage.

everythiong in lfe involes trade-offs!!!!!!!

best of luck thinking out of the box.
bob