Has anyone added a small subwoofer to 2 channel and been thrilled with the result?


The subwoofer can of worms.
I’d like to add some bass to my otherwise fine 2 speaker setup and have limited space so perhaps a single 10in?
After a few weeks of research the only conclusion I can come up with is - everyone agrees they have to be setup properly. Every brand and technology has their own following and most recommend using 2 (which I don’t want due to space concerns). My room is 12 x 13 ft with box raised ceiling.
After much research, these are the subwoofers I’m trying to pick from, for various reasons:
Rythmik FM8  - lots of hifi fans
JL audio e110 - fantastic support
REL T/9i - sort of a gold standard
KEF R400b - interesting technology, makes me grin. 

I've never heard any of these.
System:
Hegel H160
SF Concerto speakers on stands.
Ben
casteeb
I have a 2nd system in a smallish room (10x18) with WharfeDale Denton 80th's (5 inch drivers).

Space and aesthetics were constraints for adding a sub in this room, but I ended up buying a small sealed sub by Cambridge Audio - the Minx X301 (8").

Like others here, the small sub really helped improve the sound.  I'm not a base-head - just needed a more weight, and the little Minx did that.

I had two Minx subs in this system for a short while and that was indeed better.  I have a MiniDSP and will probably play with that in this system at some point.


It may take a few passes – or even a few days – to get things just right. You might even upset a few neighbors or roommates along the way. But that glorious moment when your subwoofer is delivering the kind of bass that makes your spine tingle is worth any associated work and grief. Have fun! => https://goo.gl/VgHZ6R
@casteeb 

I am a firm believer in subs regardless if its a two channel system or not. There is no sense in missing the information in the lower octaves simply because it's a two channel system. I guess Im just not that much of a purist. So if adding a sub gives you the bass response you want then sure as long as its done right I say yes. My amp does not have a sub output so the sub I use in that room is connected inline with the speakers, and I use the crossover on the sub to make it disappear. Sounds amazing. In my larger room I use two subs to balance out the room and it works well. I say get that bass. 
If using an active crossover that also has capability to connect a sub(s) and vary crossover points for the main speakers and the sub(s), my understanding is to set the crossover on the sub to it's highest value and then use the crossover to set the actual sub crossover point.
Am I wrong about that?