First Bi Amping Experience

@melbay - With the jumpers removed on the speakers, I assume the subwoofer outputs (or preamp outputs?) from your Coda integrated are running the Crown which then is wired to the bass speaker inputs on the Signature SE's.  Then I also assume the integrated amp's speaker outputs are wired to the Treble speaker inputs on the Signatures.

With the extra gain knobs (and gain stage) on the Crown, you can affectively increase (or decrease) bass response (below the crossover point of 180 hertz) by driving the two 10's in your speakers to a higher level than when your Coda integrated amp was running the whole cabinet.  That may be why you are finding the need to get rid of the REL and hearing more information in the low frequency output of your speakers.

Also, (only my opinion) having the two 10's on each side in the same plane (now driven by their own amp) and using the internal crossovers may integrate better than having the single REL subwoofer.  There could have been some phase cancelation or other issues with the REL placement / integration as the Signature's 10-inch drivers did (or tried to do) the same work as the REL sub, but in different locations in the room.

I am NOT criticizing in any way and have done this same type of thinking myself in other systems (and currently bi-amp my main system).  Crown's have good damping factors and can sound pretty good in home audio in certain situations.  Enjoy!!

@Carlsbad2; True as to a couple of watts. However it's the transients in demanding recordings that eat the daylights out of watts. Particularly low frequencies. It take a LOT of current to move woofers at high SPLs with difficult tracks. That's where the reserve or "margin" that big subwoofer wattage comes in handy. 

In my system I added a pair of Bryston 700Bs to drive my 6 woofers (tube amp for the mid/tweets) and the difference in bass and musicality was substantial. 

Regarding wattage and for what it's worth,  I normally don't use more than a few watts per channel, but DO use every bit of my available 7200 watts at @8 ohms in one of my rooms when I want my fix, and before someone makes some condescending comment,  I do it because I want to, because I can, and I am not a kid playing club music with the bass playing louder than recorded.  I am a 57-year-old woman who listens to music, just like it sounded at the last live concert that I attended, the way the artist intended, and I love every minute of it when I do it, and before some know-it all tells me that I they value their hearing, so do I! By the way I used to teach a hearing conservation class and I can tell you that it's not all about sound pressure levels, it also has to do with duration of exposure and the frequencies one is exposed to.  My hearing is perfect, as per my annual audiograms and those around me often wonder how it is that I can hear things that they cannot. So, enjoy your music "your way"!