room setup suggesion needed

Square rooms are tougher, acoustically. Consider the possibility of working a corner as the "center" of a stereo pair (as well as moving the speakers out from the "front" wall). Because you’ve referred to "rehearsal" space several times, I’m assuming you are playing instruments in the room with or without the hi-fi accompanying.

Jim Smith’s book isn’t a bad place to start. Measurements are good but only as a starting point.

I’ve had the same core components for a while, moved across the country, different room, different layout. Huge difference in sound (the current room sounds better than the old one).

I don’t use a ton of acoustic treatment, mainly bass traps. Sonics are good, not only at the "sweet spot" but in seating pretty close to the back wall (which is filled with LPs).

I’m no guru, just a longtime hobbyist.

PS: I DSP'd my subwoofers, which do not run through the same circuit as my main loudspeakers (horn type, which solves some issues and creates other issues). 

@grislybutter budget has nothing to do with the acoustics, its simple rules of proportions. Either you have it or not. How much you paid for it or how old it is, is irrelevant.

It is very simple, every concert hall has specific size shape and proportions, stage to audience, for instance full set philharmonic orchestras can fill room in ratio 3/1 where 3 is audience and 1 is orchestra. Now if you take quartet or duo they can do ratio 20/1 but in order to keep those proportions the adjusting size of the rehearsal room. 

@mijostyn - I decline to play with you anymore. I’ve shared my beliefs based on measurements and hands on experience, which I believe is all backed up by research which you are best left to your own devices to find.

@ssg308 got it. Always learning.

@whart  point taken,  I'm planing to do some new arrangements in the room over the weekend I wonder where it will get me.  I need to move point of impact of 38Hz wave about 2ft forward, the only thing I can't do anything about is ceiling height. 

I build great sounding rooms before but never for speakers that size.