@sameyers1 Interesting advice. Chuck really enjoys taking Erik and many others to task for recommending acoustic treatments, maybe you just haven’t read enough of his posts…yet. You must be aware of what he thinks of Levinson gear…Your post was clear, lucid and not rude to the OP. Your post is also cognizant that maybe not everyone wants a forest of subwoofers and wire strung across the back fourty…
No doubt you understand that classical symphonic bass is not mono. Maybe below 100 ish hz it is..but you probably also understand the rich vibrant and loud harmonics of a scaling standup bass…way above 100 hz. A swarm is but one answer, with some texture , imaging and harmonic downsides. Flat frequency response is an upside. I know a certain Strad owner with great high passed main speakers with integral subs with 11 bands of analog EQ below 120 hz. No swarm desired or needed. High passing the main amp for magic midrange is crucial. I complimented your ability to detect clipping in your great system.
@lemonhaze is correct, RT60 is an excellent tool for working the room. Some of us have achieved near perfect control room RT60 numbers using modern measurement tools, a variety of room treatments , natural furnishings AND listening . We bring in peers to help. Fun.
Finally rock is not a good audiophile sub test, a Fender Precision or Kick drum just don’t go very low, so it’s more about mid bass slam and freeing up the mains and main amp to reproduce those IMD free as @rauliruegas so astutely noted.
:-) enjoy the music
Jim