I use 2 RELs and adjusted them with test tones to match the main speakers...the tests tones really were a starting point to let me know where the main speakers drop off and my trusty ears do the rest of the evaluation. I did put "chicken head" knobs of both subs to more easily adjust the levels, but some recordings demand a little nudge in the bass...in either direction...I also have a Schiit Loki which I rarely employ (it's transparent when switched in or out of the system) but I'm glad it's there when I seem to need it...highly recommended.
Different subwoofer settings for different albums?
So a dealer I know told me that he doesn’t use subwoofers and doesn’t know anyone who does (!) because he finds that every record has different levels of bass and would require a new subwoofer crossover point to properly blend with the main speakers. Anyone else have this experience?