If you don't have any room correction equipment, then I would say +/-5dB, since that is what I shot for.
I find that the biggest improvements (without electronic or digital correction) are from a combination of speaker and chair placement. Often we as audiophile put both (chair and speakers) too close to room boundaries.
I find that the biggest improvements (without electronic or digital correction) are from a combination of speaker and chair placement. Often we as audiophile put both (chair and speakers) too close to room boundaries.