Rooms that are the most problematic are ones with the dimensions the same, or easily divisible into each other:

10 x 10 x 10 (terrible scenario)
20 x 10 x 10 (not much better)
12 x 15 x 27 ( much better)

The remedy is treatments (bass traps/accoustic panels), multiple subs, followed by EQ as a last resort.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85