My experience with room correction involves two different correction systems. The first DSP/RC was part of Sanders 10 speaker system. Roger Sanders programmed and included a dbx VENU360 DSP/digital crossover with the system purchase of his 10 series electrostatic speakers. I bought a dbx from Sanders to use with Innersound EROS speakers. The EROS speakers are the predecessors to his Sanders 10 speakers. The crossover portion of the dbx is necessary for use with Sanders or Innersound speakers. The DSP/RC RTA (real time analyzer) in the dbx is set up using a microphone. Full set up process is easy to do and gives the music the right weight and resolves room and bass resonances. In other words, the music sounds really good! Check the Sanders web site for more information.
My current RC system is a Lyngdorf TDAI 2170. While this unit is an 80 watt integrated amp with Room Perfect room correction, I don't use the amp portion of the 2170. The 2170 is very flexible and I can use it as just a preamp with Room Correction, which I do. Room Perfect allows me to set the crossover point for the high pass and low pass filters so I send the high pass to a Sanders Magtech amp which drives Magnepan 3.7i speakers. The low pass is sent to a Dayton Audio sub amp driving four AudioKinesis subs. Room Perfect room corrects by analyzing, via a microphone, various test tones and sweeps taken from random microphone placements (usually seven or eight locations) in the room. The correction produces a sound without the negative influences of the room. The bass is clean and articulate (though I believe the four sub system from AudioKinesis has a lot to do with that). Soundstage, depth and detail are outstanding. The sound I hear makes my toes tap and when my toes are tapping I know the sound is good. Hit the Lyngdorf website for more information.