Welcome!
What's your room/setup like? The listening environment is the second most important "component" of a in-room listening system IMO and by far the most neglected. A good room isn't small, isn't squarish, is well insulated, and dedicated. Suggest reading Floyd Toole's "Sound Reproduction" 3rd edition, the consummate audiophile primer for learning how speakers/subwoofers behave in-room. In the book you'll also learn that all residentially sized rooms have huge bass peaks/dips and how to best address the issue, via the use of carefully placed multiple subwoofers. The second best way to address room issues is via effective absorption panels (see GIK here at Audio Circle).
A cheaper room fix, that should only be used after subs and panels is DSP room correction like Dirac or REW (Room Eq Wizard) which is more flexible, harder to learn, but free). Consider DSP room correction only as the "icing on the cake." I have a dedicated 8ft x 13ft x 21ft basement room (no windows, concrete slab floor, well insulated - including ductwork and door), 3 subs, 10 panels, 3 tall randomly filled bookcases to act as casual diffusers. Setup is mid-field and use <500 Hz version of Dirac. "Special" ductwork is lined fiberglass, can barely hear the furnace 25ft away. "Special" door is an insulated exterior fiberglass door with weather seal.
Do you suffer from power aberrations (the proper term for noisy/dirty power)? Old wiring, appliances, distribution system, and substations are all possible causes. I've only heard it once, in an old light industrial neighborhood, could tell when the nearby factories shut down after 11PM. Never heard it at home. Previous place was 50 years old that after several owners had a rat's nest of wiring where a fancy power regenerator made almost no difference. Current home is in near ideal shape. If your Richard Grey unit makes no differences sell it.
