>>107092479
EQ is an invaluable tool in certain scenarios but it is not an audio panacea.
It does not change the properties of the transducers, if you fix the on-axis response, you will mess up the off-axis and vice-versa, so a reasonably good flat speaker with sufficiently flat vertical and horizontal radiation patterns is needed.
Fixing a dip or a peak caused by the room modes at one position will make it much worse at the other. Also it does not change the room itself - while reducing the volume of the problematic frequency helps, it does not necessarily help enough - I have tried EQing out mode peaks in a bad room with 0.9 sec decay at this region but it only got down to 0.6 sec, which is still too much for me.