Balance adjustment?

I've been plenty happy with a system (Parasound components/Ascend Towers) I've had for a few years now but always kind of bothered with the asymmetrical room.  There's no way I can set up the system without having one speaker close to a wall and the other with next to an opening.

I never tried handling this with the balance controls before but decided to play around with this strategy this week.  At first, I nudged it just a bit, and I didn't notice any real difference, but then I moved it almost a quarter turn.  All of a sudden the images seem sharper, but even more so, the timbre of the instruments feel more realistic.  At the same time, the bottom end dropped out a little.  

Anyone want to chime in on whether you think this is placebo effect, or if this really made such a difference?  Or how to keep the new-found clarity without losing the punch of the bass (turn the sub up a bit?)

Any advice would be appreciated.  Thanks, Andrew.
Ed5c0887 072e 4987 a9d7 6dc044a988cczwartitude
Interesting experiment.  Have you tried adding room treatment on the short side to "kill" early reflections?
My guess (not technical analysis) on the bass is that by adjusting the balance you do actually lose some of the low end output (balance adjustiment attenuates the signal on one channel), hence a reduction in bass.
Moving speakers back toward the rear wall usually helps bass...
As I posted on another thread, sometimes moving speakers in ways that are 'non traditional' can make the difference between good and great.
I can see the use of the balance control making this, too.
Perhaps try to angle the speaker with no reflecting wall towards your listening position and back off the balance? 
But, if it works, why change?
At the same time, the bottom end dropped out a little.
That's curious.

Check the phase- invert the phase on one channel only (reverse the speaker connections on one speaker only) and see what happens.

If the bass gets better, you may also notice the center-fill got better too.
I take it that you balanced the sound towards the speaker by the opening and away from the speaker close to the wall. Therefore the reduction is bass. Probably will have to reposition volume on sub, and possibly the sub itself.