Adding multiple subs, bass traps, and first reflection panels, has improved the response across all seating locations. If you calibrate using REW or the SMS-1, etc. from the primary seat, your only benefiting that location.

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