Subwoofers - crazy upgrade!

Subs were the last component I put into my system, last year....why didn’t I do it to sooner. None of my upgrades made such an improvement as adding subs = nuance, soundstage, depth, presence. 

I was listening to an interview by Magico's Peter Mackay on their new S-Sub which are way out of my price point. He made a statement in the interview that caught my eye... "Not ever speaker needs a sub, but every audio room does!" I went to my local dealer...did a session with subs and without in the same system...that was that.
Worked with REL to match my speakers - my goal was for the subs not to overwhelm my speakers (Horns), but to be the background, and to make the room better...it did significantly. As mentioned - matching is critical; also DSP/Crossover simplifies everything. 
 

This thread discusses ways to enhance your bass, including using multiple subwoofers.
https://forum.audiogon.com/discussions/all-about-that-bass

I am using the (4) JL F-113 subs because they have an in-room microphone calibration set up. Each sub has been calibrated based on its room placement to my sitting position. I find the corners to be the best in overall deep bass response.

My main speakers go pretty low by themselves, so I have the subs set at 40-45hz. and are at a low volume level to add something that the main speakers may not have.

ozzy

https://www.youtube.com/watch?v=SCWL-zusyqw

Dr. Earl Geddes knows his stuff when it comes to the interaction of loudspeakers in rooms

I have a question for this thread.  I just moved into a new house and a smaller listening space.  It's a worse-sounding room than my last, so I am currently adding lots of treatment.  In small rooms, does everyone still recommend subs with full-range speakers?