Eh hem!...Subwoofers... What do ya know?

I have 20.7 Maggie’s running full range with two stereo Kinergetics sub towers of 5x10” subs and two SVS 16 Ultras. When I hooked up the Ultras to complete my sub array I scared the s**t out of myself and literally jumped off the couch as my stomach flipped, water rippled in a glass on the table, wife jumped out of the shower and yelled about the thunder that was shaking the house to turn off the stereo due to the storm. That was out of control bass and what I suspect is the issue for a lot of people with integration.

I have a fully active set up with a Mini DSP, used REW with an Earthworks +-30k to measure the speakers and room. I followed the tutorial and used my own data in MSO and made 12 biquad filters per channel (8 of them) to optimize the room and have reached sub bliss. It is absolutely perfect and there are no modes.

I had a friend over for an extended listening session and they asked to take the subs offline because the 20.1’s are full range. They couldn’t believe the difference as they couldn’t “hear” the subs but not being on made a world of difference. No room for the subs as I read above? Make them into end tables like I did. Very WAF friendly with a 1” thick piece of glass on them. Guests have no idea they are speakers. 
If you can take the time to do it right with a sub array (four is the minimum in my opinion) you won’t regret it. 

Hi m-db,

      I wish I could speak to it but I didn’t take advantage of the SVS DSP. I didn’t think it could really compare to the processing power of REW and MSO. Using those programs with the Earthworks Mic I could see what was happening in the room and angle, move, shift the speakers for an optimum result. As others have noted, placing four 150lb subs in the room can be challenging. I also was integrating two subs that don’t have the DSP built in so I opted for one total solution rather than mixing them. It’s pretty exciting to see the hot spots and what MSO does to combat them using time delay, inversion and some wild looking slopes. I also time aligned my mains to the listening position at the same time. It’s easier than you think once you try. It’s just a path that isn’t well tread and it took me a lot of reading and trial and error to get it all to work. I’m a firm believer that the two most important parts of the system are first your speakers then the room. 
I bought the SVS because of their quality 1,500W MOSFET amps and massive driver motors and bracing they have internally. They can keep up with the Kinergetics driven by my Pass amp very well. I will also say that the SoundPath feet offered by SVS are a huge bargain. I had nasty vibration induced distortion in the room till I bought those and put them on all the subs. The rubber durometer is perfect and totally isolated the subs from the floor and the bass became so much clearer. I also have everything connected via balanced cables, it’s dead quiet. You can hear a pin drop and the ‘lovely’ tape hiss on older recordings. 
The OP asked when we learned about Subs and I knew how important it was playing in an orchestra as a kid. There are vibrations from a live performance that can’t be “heard” but are essential to the experience. That’s when I started reading about music reproduction and the physics behind it. . . Love how accessible sound is. The highest sound we can hear is 1” long the deepest is 50’ long. It’s amazing. And once you know the science it makes sense why a sub array is such an effective tool to counteract the physics of the room. You’d need 50’ of dampening material to absorb the wave and prevent a back wave from reverberating in the room which simply isn’t possible and why one sub is usually so hard to integrate properly even with DSP as the other speaker waves are truly the vehicle for DSP to be effective. What a great hobby. . .