The ATCs are positioned > 1 m from walls...
What I meant was even ignoring sighted bias, if the speakers are not placed at near identical location the room mode can play a big effect, say if your location of atc is resulting in a lot of cancellations at mid to upper bass region levelling the overall SPL using music can result in a very v shaped FR, or if the 8030 is put into A bass null and you level it with a 1khz tone can result in same subjective impression.
So as I said those a wild guess of your observed impression with the data of speaker. Of course it can be the sealed vs ported issue at play but from non EQ in room measurements I’ve seen the room modes are creating a much much larger difference so putting them at different spots can already have a huge effect especially on bass where it radiates 360 degrees