<font color='#000000'>I'd move the rears towards the center of the walls the couch contacts, so that everyone on the couch is between them.
Ideally move the couch a bit forward each way so folks can walk behind it, that will allow for the speakers to be more towards the back than to the sides, giving a slightly better positioning.
As far as the fronts, experiment a bit. I bet you can get decent results with a bit of trial and error.
Not sure how well it would work, but maybe also doing your listening from the inside corner of the couch might be a good idea, at the last it's probably the most comfortable spot
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