Subwoofer help needed

I am looking for a sub (or pair of subs) to go with my recently purchased ATC SCM7 v3 speakers.
My total budget is around $1000 right now.
My room is 11’ by 20’.
I have done some research and will be either purchasing or building some bass traps.
I tried out the system with a pro audio sub I use for performing that is just physically far too big for the room and it sounded great although I am sure a sub intended for home/Hi-Fi use would be much better.
This little experiment taught me my room is very “live” and some treatment will be necessary, which is fine.
Do subs with room correction negate the need for room treatment or just flatten the frequency response of the speaker?
I am ok with buying used although used isn’t always a cost effective option with a sub when you factor in shipping.....
I have been looking at Rel, Syzygy and SVS as well as Martin Logan (Dynamo 700 closeout at $399 each?), Kef and Elac.
Thank for reading and any suggestions you may have!
The key to great bass is more to do with the number of subs than anything else. The quality of bass that can be had from 4 or 5 subs for a total cost of around $3k is such that it is the one thing you can do and be happy for life and yes on that budget if you do it right. 

You can do it either with individually powered subs or multiple subs powered by an amp or a combination of both. I have both. It is awesome. Best bass I ever heard. By far. Not even close. 

So get whichever ones you want. Just plan on getting to four, at least. Then your main decision is do you want great bass now with 4 moderately priced subs or would you rather get 1 or 2 now and add more later?

I’ve had Rel for years. They do much more than just augment bass. They make the main speakers image much larger than they do without the sub. This is why I chose 2 Sumiko S-10 which is a Rel clone of the S-5. Sumiko was the distributor of Rel for many years. Thus they knew the design and how to clone it. You may be able to find an s-5 or S-9 on closeout somewhere since they are no longer made.

Here’s an S-5. Two may work or look for S-9.  BTW I have no affiliation with either company
Hey kids! Don't fight! New Rel is a dessert topping AND a floor polish!
Used RELs are out there for cheap...I own 2 and they're amazingly good subs that change everything in your rig for the better. Mine are class A/B 150 and 100 watt that blend superbly, and cost 200 bucks each.