Or go the UMIK-1 and REW path. The UMIK is good down to 20hz +/- 1dB. Still more expensive than RS but better performance.
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975/7075/SMS-1
Aperion Verus Grand Towers & Bookshelves, Verus Forte Center, Infinity Surrounds, Ultra-X12
Oppo BDP-203, XBOX360, Xbox One
LG 65" OLED
RR2150 w/Klipsch SCR-2