Re: Lowering subwoofer volume
you may want to try a minidsp 2x4 HD.
alternately, a Henry Engineering TrueMatch may work (or something similar)..I bought mine through Markertek (they may also have another suggestion for you).
not sure what your interconnects are (eg RCA, XLR, combination of)
* LG OLED65E6P, BenqHT2050A
* Anthem AVM90, Rogue ST100, VTV Pascal 7 ch
* Sierra Towers/Horizon (all ELX RAAL), S2EXv2 surrounds, HTM200SEx4 heights, Rythmik E15HPx2
* VPI Classic 1+ (VTA & Fatboy Gimbal), PE Eagle/RR, VAS NOVA, Soundsmith Paua, Manley Chinook, Bob's Devices SUT, SugarCube 1 mini
* Oppo 203 & 103D, EverSolo DMP-A6
* miniDSP Flex, Audiosensibility & Blue Jeans cables, Symposium & Isoacoustics, GIK
* For RDJ: Anthem MRX720, Sierra LX, Luna Duo v2 center, CXNv2, TBD