Balance knob ..

So I'd say I've been a budget audiophile for 40+ years. Used to sell audio at Audio Warehouse in Cincinnati in the '80s. Currently I have a pretty big room with 12' ceilings, but different open areas behind each of the Maggie 1.7is and the Emotiva BASX 10" subs behind each. All driven by an Emotiva XPA-2 Gen3 and old CJ PV-10AL preamp. Listening mostly through a Bluesound Node 2i. CD player is a Panasonic Aventage BD1060 disc player. I have the sound, honestly, pretty damn great. But I am realizing a bit of bias to the left speaker. I think this is because that speaker has a lot space behind and to the side whilst the right has less and more complicated space behind and a closer side wall. 

I have always been told - and believed - that you shouldn't ever mess with the balance knob. But if the sound is a bit UNbalanced isn't that what it's for? Just to "balance" the output? But then I think with more signal going to the channel that the knob is turned to - which will screw-up imaging, soundstage, depth, etc., no? 

I am kinda stuck cuz I can't move the speakers or have a dedicated listening room. 

@noromance Fair enough. I didn't mean to derail the thread by responding to those that think a balance control is the Devil's work.

I've done a lot of experimenting with positioning and sound treatments in my main system. I think my preamp has a balance control, but I've never used it.  I have some spaces limitations there also but have been able to get really good imaging. 
Eliot, Sorry, I have NO idea what you were talking about WRT that line conditioner. That whole thread just completely went over my head. 
The Chase Unit. Did you look at it's features? Not understand it?

Line CONTROLLER (not conditioner). Volume, Balance, Treble, Bass, Input switching. Noise free 105dn S/N

I am suggesting in your situation, asymetrical speaker locations, asymetrical reflecting surfaces: in addition to Balance, you might benefit from Tone Controls.

thus the linked Tone Control thread.

I am a big proponent of remote Balance, even in a perfectly symetrical space with perfectly matched speakers, to adjust for individual tracks with slight balance issues.

LOUDNESS Contour, Low Volume Bass Boost: I can understand young people not being aware of it, and many young and old pre-disposed to simple signal paths, However, you owe yourself some Bass Boost at low volume, especially if getting into Jazz.
Newbie, bad idea. There are two factors that determine center stage. Volume and phase. They both have to be right on for the best image. By just moving over you change relative volume but you leave phase behind and blur the image. With a balance control you change the volume without changing the phase relationships. 
With the best systems a balance control is vital. The balance of many recordings varies 1 to 2 db which is very significant. I frequently have to adjust the balance a little to get the right image even on digital recordings. If you do not hear the variation in balance between recordings you have work to do. 
jk, use that balance control as much as you need.