So tried a sub crawl again and on the right side of the couch; there's nothing. No 30-40hz. it's a null. I can't move it forwards or backwards so I'm sadly stuck with this position

So here's an image after a lot of tinkering.

Red is trueplay off, and brown is on.
It seems that trueplay also causes a huge dip in the 30hz range. Is this to be expected? Otherwise it looks pretty good.

I don’t use Sonos TV products, but I have found that Trueplay tuning is both necessary and close to fool proof where a Sub is in the mix for music play; that said, I do need to bump up the Sub level to +2 after tuning. 

One attempt you could make is to run the Trueplay tuning again with more time doing the phone waving things from where you listen to the audio, and see if that improves things.

And trueplay is also a Sonos opinion on how things should sound and you may not agree with that. In which case, turn it off and see if better results can be obtained by playing with the Sub audio levels and the EQ sliders.

True play is way better, since it also balances surrounds and left right levels. Which is something I can’t do manually.  About the sub; even if I put it at plus 15 the 30hz gets pulled down just as much as the 0 setting when trueplay is enabled. Disabled it does increase with the setting. 

My issue is that on the couch the right side is fine and has all the bass. But the left is in a null that can’t be increased without making the surrounding area uncomfortable. So I’m back to sub crawling and taking measurements. Found a few okay spots, but each had nulls in different shots like 50, 90 and 110 hz. And also a spot where the bass just didn’t exist. 

Sorry about the physics.

In my college apartment I discovered a monster peak and placed a chair on the peak. Bass exploded  from within the listener’s body. This was a favorite spot for male listeners. If I moved the chair a few inches the peak was gone.

Move SUB away from the wall. This will reduce the peak magnitudes somewhat. Also, try placing SUB under the couch if possible. This will place SUB close to your listening position and tend to over power the room modes.

So under the couch removes ALL the bass somehow. Away from the wall also removes a lot of bass. At least for the person on the left side of the couch. The right side is always, well, right.

Wouldn't want to sit on the floor just in front of the couch though. Around the couch is a 10db increase on the 30-40hz, so it destroys your ears when you get up from the couch. But ON the couch it's now pretty good.

My room isn't rectangular, so it's a doozy anyhow. But I put the sub left of the tv between the cabinet and a small wall that comes towards us for around 5ft then opens up into the kitchen. It seems to be the best spot even though the kitchen sucks some frequencies away.

Red is on the right side of the couch
Blue on the left side. Seems quite balanced.
This is a 2ft difference in seating positions, changing the sub 2ft changes nothing.

Trueplay brings the 30hz down to 65 though, probably because of the surrounding area.

A cubic room would have the most pronounced modes, square would be next.

This is the room, living and kitchen are one open space.
I've got the sub set up at position 3, and took the sweeps from the previous post from there as well.

I'm going to try trueplaying in the "weak" spot on the couch to see if it doesn't bring the 30-40hz range way down and maybe that'll get the best results.
With sub crawl on the weak position there is NO better spot to be found anywhere, so I guess this is as good as it's gonna get. And to be fair; it's a good deal better than no sub.

You have two #3s in the drawing, behind the chair and in the corner.

Expensive but adding a second sub and keeping both out of the corners might give you more even sound. I’d lean to behind the chair and between the table and Ikea.

I put it at position three on the left side of the map.
I sat down on the left (weak) side of the couch and ran trueplay again and got a pretty nice EQ. Happy with the results.

Purple/brown was without trueplay, green/blue is with trueplay. Got rid of most nasty dips.