Subwoofers are a superlative room treatment

Several months ago I posted about how KT 170 tubes improved my overall sound and in particular improved the boomy bass I was experiencing with KT 150 tubes.  During the discussion @Mijostyn suggested that my Swarm subwoofer system was likely inadequate for my S7 Magico speakers which each have 3 10" woofers and adding more subs would make a big improvement in my sound.    The swarm has 4 10" passive speaker cones.  @Mulveling opined that I likely had more than enough bass with the S7s alone.  I had spoken with Mike at Suncoast Audio who also brought up adding more subs to the system.  My low end was much better with the new tubes and it seemed counterintuitive to add more subs to tame the sound, but Mike has never been wrong regarding my system.  So I took the plunge.  He recommended 4 B&W DB1B subs with 2 active 12" drivers with DSP.  I bought two and he let me test drive an additional two.  These subs are staggered in the room, similar to a Geddes set up, but none are behind the listening position.  I wasn't really sure how my sound would end up and was actually a little nervous that the bass would overwhelm the overall sonic presentation.  My fears were unfounded.  The bass was definitely better than before-more focused and rich.  But the big surprise was that the overall sound was vastly improved.  The sound stage expanded with more air between instruments.  The tone improved as well.  My wife (with hearing aids) and daughter who are very familiar with the system each said the same thing within 10 seconds of listening.  "It sounds so clear".  This "upgrade" has had by far the largest impact on sound in my system-more so than upgrading to the VAC Master Preamp.  So reflecting on why it is so much better than my previous sub array- its clear there must be a ratio of subwoofer square area and woofer square area that is optimum.  Or the DSP aspect set to the listening spot for each sub, or a combo of the two.  @mijostyn had alluded to the ratio in my last post as being important.  The set up is straight forward and there is no connection with the speaker crossovers.  The crossover on the subs was set to 70.  I post this so others may be encouraged to consider a similar approach.  These subs improved the low end, but the most impressive aspect is that they act like a whole room sonic filter of the highest order-without altering the sound from the mains.  Incredible. My room has had acoustic treatments consisting of corner bass traps with diffusion, first reflective point dispersion/absorption, quadratic diffusers, ceiling absorption and HFT's that have been in place for years.  The subs are king of them all.