Sounds like room acoustics. I can promise that the first time you play with an SPL meter and some graph paper you will be horrified at the terrible, lumpy response you are getting from your nice accurate speakers.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8