An open corner is usually a "good thing" because it avoids the focusing and reflecting that happens at low frequencies. Of course, what's beyond the openings is a factor too.
Symmetry is also important, so you'll want the loudspeakers at the end where the walls are the same on both sides. Then treat the first reflection points on the side walls and ceiling, and add bass traps in as many remaining corners as you can manage, and you'll be way ahead of 99 percent of audiophiles.
--Ethan