Which subwoofer?


I have a small room (10’x14’) and am wondering if a subwoofer would help. If so, which one?

I have Martin Logan electrostatic speakers with  8” powered 200 watt woofers and 8” passive radiators.  The bass is articulate, but not very deep. I am wondering if I could get more bass volume and depth without loosing detail with an additional subwoofer?
I have tried an 8” Velodyne, but could never integrate it with the Martin Logans so I sold it. 

The Martin Logans are powered by a 200 watt McIntosh receiver. 
Any thoughts?


kenrus
I am using the ML Dynamo 800X with my ML ESLs and with the built in Anthem Room Correction and numerous settings for low pass filter, type, phase, volume, listening modes, 20-30Hz level, etc.  It is a sealed sub woofer and should blend well with any ML ESL speaker.  They make larger in the 1100X and 1600X but in your small room 2 of any such as the 600X or 800X should work well.
Take a look at HSU research subs.  They are of fantastic performance for the money. 
Thank you all for your thoughts. 
I’m really liking the idea of the RELs. There are multiple dealers in my area that will allow me to get a listen. 
I’m not one to mess with two subs, especially in a smaller room. Bass, below 100-120 Hz appears non-directional. I did not say non-directional dogmatically. The mid-bass and midrange give the sense of directionality, so two subs for this purpose are not required. And with placement, integration, crossover, volume and phase, one is quite lovely. 
The key is proper room pressurization. 
I have a Rel T9/I and a medium room - exquisite.
look up the new T9 and check the extension very nice and very low for its size.  
I`m using 2  12" HGS Velodynes with my 3.6 Maggies the integration is outrageous, I also suggest looking into a integrated amp or tube preamp & SS Power amp combination in the near future.