Digital Room Correction For Speakers

1) Treatment, which you already have.  
  
2) Mutliple subs, either through Geddes’ approach or the standard symmetrical one. 
 
3) EQ. If wanting to use it also as your DAC/pre-amp, the MiniDSP SHD with DIRAC is high enough in quality where it can be considered audibly transparent. 
 
You should always take multiple measurements, but 90% should be around the main listening position, with some spurious measurements in other seating areas (which aren’t close to a side/rear wall).

Some more experience here:

https://www.whatsbestforum.com/threads/dspeaker-anti-mode-x4.26851/

Thanks for the great review. I need to look into this system.

There´s also Trinnov in that price range.

One thing I believe is that active room correction actually means different speakers can compete in the same room on a more even basis. You hear that the difference between speakers after correction is actually less than before, which means the room interaction on different speaker accounts for the main difference in sound. You can now concentrate on dynamics, resolution, tonal qualities, edgeness etc that is left.