Martin Logan 13A's with Rel subs? A match?

My experience with stats is that they always sound more coherent without a sub. At that price point, I would hope the 13A's aren't failing in that regard. If so, you have my sympathies for buying Martin Logan. Move on.

@mikepaul   To your question of one or two subs, I think the answer lies in the amp you are using.  If you have a single stereo amp, the REL connection will capture all the bass.  However, if you are running monoblocks, you absolutely require two subs.  I run a pair of REL S/812s and I'm very happy with them.  As noted above, the wiring of a REL sub is very dependent on whether or not the amp is truly balanced.  You'll know right away if you get it wrong as your speakers will be trying to jump out of their enclosures.  🤣   Cheers.

middlemass what is your experience with stats?

I am confused, am I correct in thinking the Logan 13A has room correction in their powered subs and go down to 24hz? I bet they go as low or lower than most of the rels minutes top few models. 

james633 yes they do and it works well. The speakers are exceptional.

But that won't prevent me to contemplate building up my system.

I'm still on the fence regarding subs. They might muddy up the sound or take it to another level.  That's the gamble. And an expensive gamble.