I wonder if anybody here realizes that simple and proper room acoustic treatment will work far better than any electronic "correction". Electronic means can only attempt to _cover up_ room problems - it cannot cure the source of the problem. The problem will still be there, and the acoustic resonances will still be there.
Acoustic treatment cures the room problems at their source. Especially for critical music listening, actual, and real acoustic treatment is going to yield a far more natural sound field than any electronic "correction" can ever hope to achieve.
And those studios who supposedly "use" this electronic correction...the acoustics are designed by some of the best acousticians in the world. They do not need to use this device. There is nothing to "correct".
Information about the basics of acoustic treatment, in addition to other subjects can be found
here.