There are some problems that cannot be corrected through room correction EQ, namely the Speaker Boundary Interference Effect, which happens when the reflection from a wall is out-of-phase with the signal that you want to hear, and produces a deep valley in the frequency response.

You could try boosting at the frequency that the valley is at, but that makes both the signal _and the reflection_ equally as loud. Therefore, they cancel out in almost the same manner for basically no net gain.