I am a devotee of high quality DSP room correction. I have done some room treatment, heavy curtains behind the speakers, overstuffed furniture, etc., but my system didn't come into focus until I had programmed my DEQX DSP room correction and reprogrammed and reprogrammed it. Right off the bat I decided to sacrifice seven or eight dB of woofer sensitivity to enable equalizing the bass by pulling down peaks instead of attempting to boost dips. This was possible because I had all kinds of headroom in the bass, 104 dB/w/m sensitivity woofers coupled with a 300 watt amplifier for the four ohm load of the woofer.
Programming the DEQX room correction was a monumental task for me, but I kept refining it until my fully horn loaded, triamplified, DIY speakers sounded quite good to me. Then I read about company approved DEQXperts one could engage to give the DEQX DSP a truly professional programming by means of connecting PCs and holding a Skype call to get the work done. I hired DEQXpert, Larry Owens. He turned out to be brilliant at the task. After performing speaker calibration, speaker correction, time and phase correction and finally room correction My DIY speakers sounded absolutely splendid to my ears. Larry hit it out of the park. This was 2017, and I have had no need to change anything with the DEQX. The system has a smooth frequency response from the low 20s up to 20 kHz. It is properly time and phase aligned and the crossovers at 200Hz and 8 kHz (16th order) are inaudible to me.
I have some experience with automatic DSP room correction with my Marantz AV pre/pro in my HT system, and while it wrought some improvement it is in no way comparable to the results that can be achieved with a high end DSP like the DEQX.