Sub with Avalon Ascendant?

Just curious if anyone is using a single sub with their Avalons and if there would be any integration problems?
I'm using one James EMB-1200 with my Avalon Avatars.
I have another, but I need dedicated lines before I install the second sub.
Both the James & my Avatars are sealed, they mate very well..

I have been down the sub route (not with my Ascendants) but with my JM Labs speakers. I was using a REL Stadium III and could never get it blend to my satisfaction for all content. It seemed like I was adjusting it depending on the content more than I would have liked. Perhaps it was due to the fact that I didn't have dual subs or it was a room problem. I have since moved my system to a dedicated room and have paid particular attention to the bass to eliminate any standing wave issues. I wont't be going back to a sub.
I had the opportunity to trial a REL G1 sub with my Avalon Eidolon Diamonds. This may sound strange to Avalon Eidolon owners but in my upstairs room, for some reason I get a significant drop off in bass response below 40 Hz with only a slight increase between 20-25Hz. I used one REL G1 and hooked it up directly off the speaker terminals on the amp using the Neutrick cable. I set my slope on the sub at 30Hz and set the volume at 20 (the G1 comes with a great remote that you can dial in the bass response from the listening chair). It mated seemlessly and its driver is equally as fast as the woofers on the Eidolons.

I would not hesitate to try a sub with full range speakers. It can open up the soundstage even more and improve low level detail and imaging. Plus it can give that visceral bass response some may crave. One caveat though is that to get a great response like I experienced, I'm betting you have to spend $$ for the sub. The REL G1 ain't cheap, but it can potentially change the sound of a system dramatically for the money spent.

Thanks for your help. Integration with fast speakers has always been a challenge but I'll use what I have since my choice of music has little or no bass (classical).
Even though I have full range speakers, I found by adding a quality sub ( Taylon )
I was able to enjoy the low end that Classical does have. I was able to cross this sub over at 70hz and with proper placement integration was not a problem.
It seemed to add just enough weight to the music. Jazz and other forms of music were also more enjoyable.
> my choice of music has little or no bass (classical)

Now I've heard it all... Unbelievable.
Now I've heard it all... Unbelievable

Actually, a lot of violin/cello with good mid-bass but not the bass I associate with jazz.

How about the JL Audio F112?