check ur eq result.preferred not touching peak of positive or negative db.
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can use large for front L--R. so that it give better bass matching  instead of sub only. becos u are mixing few kind of british and japan brands.

bass setting from avr leave 120hz until u have finish tune everything. then can adjust according to room create more kick. 80hz too low probably killed all the intended boom from action movies. unless your main usage is music.

boston xs 3" can go 120-150hz. too high crossover feel unnatural + less clean bass fron subwoofer becos it will mix all small channels together.

audyssey function should be boost bass at low volume, while reduce bass as u go louder. like mine can go from normal -43db (37%) all the way up 0db  (80%) while the bass boom is under controlled. no need touch behind the sub at all. reference offset is the boost target. lower =less treble and bass.
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your case is rear spk crossover 200hz make a lot mid bass signal being sent into subwoofer. result is very boom. run the staircase test like that surely shake whole room

recommended to adjust rear spk level yourself as audyssey often miss compensate after multi seat eq calibration.

by the way, have fun