Single vs. Dual Subs

Just for the record, I do this regularly with a single sub, traps and careful use of an EQ.

I guess the advantage to doing it this way is that there is less trial and error involved. If we ignore the EQ for a minute then room treatment only attenuates reflections but it happens over a wide range of frequencies. The only limit is how much space you're willing to give up to absorbers e.g. to treat a problem at 80Hz you're looking for 1m depth of treatment... 1.5m at 60Hz etc. With EQ I think the only compromise is that you are getting a flatter response at the listening position but probably making other places in the room worse.

Theoretically with multiple subs you should be able to cover multiple frequencies but it could easily turn into a game of 'whack a mole' where you treat one node only to reinforce another one. I guess some of you EQ each sub individually to get around this.

Personally low frequency room response is somewhere I'm willing to compromise... treat the worst modes and live with the rest. Each room has imperfections which are part of its character if you're willing to think of it that way.

Don't forget that ours ears are not the only way we experience the music we're listening to.  There are pressure sensing structures  called Pacinian corpuscules distributed over the entire surface of our skin that contribute to our perception of lower frequencies.  

I'm not sure whether these sensors are wired to our brains in a manner that allows source localization, but it would make sense if they were.  

It's a fact that having appropriately distributed multiple subs (more than 2) improves the bass.  I wonder if anyone has looked into whether it makes a perceptual difference if you try to keep the channels separated from left to right when you place them.

Recently blew a sub in the living room where I run a two sub system for video.  Decided to move the matching sub from my listening room there and replace the listening room sub with something newer.  New Martin Logan 800 X (10" sub) to augment the 8" woofers in my classic Acoustats is working beautifully.  Everything adjusts from a phone app at your listening position and it has Anthem Room Correction built in as well.  Sub is tucked away behind the couch wood arm at the far right.  It's gets lots of reinforcement coming out of that couch  "baffled" corner.   https://www.martindareff.com/Other/HDR-Treated-Images/i-3ZfL6Gq/A

Using a Dual Rel T7i subs make my soundstage become wider and deeper, comparing to one subs only. Also, the bass goes deeper and smoother. I am not a scientist, so I don't know how to explain it, I can only report what I observe. Also, placing the dual subs right next to the speakers closer to the side wall makes the soundstage wider, comparing to closer toward the center .

I ran a single powered sub (15" driver) for awhile in my main listening room and then added a second.  The second made a considerable difference to the sound.