Dual Subs set up advice


Can anyone give me some advice on best practice to run dual subs? I have two Martin Logan Descent i subs for a strictly two channel system with ML Prodigy mains.

My options are:
Speaker level in
RCA in (sub has both left and right in for single sub use)
Balanced XLR (LFE)in (only one XLR in)

I am running the Sonic Frontiers Line 3 which has both balanced and SE outputs.

As of now, I am running them from the 2nd post on my Krell 300M amps but was wondering if it would be just as well to run SE (rca) left out from preamp to left sub in and vice versa for the right. Or, go balanced #2 outs (balanced #1s used for amps) to the single (XLR) LFE in on the subs.

Thoughts opinions?

NAK8
nak8
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I'm running a pair of ML Descenti's with SoundLab U1-PX's and for me the best feed connection has been to piggy back onto the main speaker terminal posts and feed that back into the RCA in on the sub.
another comment unrelated to the hook up method. Have you ever tried running the subs at different locations? I was at a friends house, he was running ML CLS mains and had two subs. One sub was in one of the front corners of the room. The second sub was placed all the way in the back of the room - middle/center. The depth of the sound stage was amazing. If your cables are long enough, give it a shot and see what you think.
You had better have a large room if you want to try ML Descenti subs in different locations, not to mention moving them around.
I have only one word which can describe moving SoundLabs once they are spiked - HERNIA!