Open Floor Plan Listening Room

This is all extremely invaluable information.  Wow this forum is impressive.  I'm processing all this info; a lot of what you say makes a lot of sense to me.  I think I will have to play with it a bit alternating between high input and low inputs.  I do know that REL absolutely recommends using the high inputs to push the same signal forward through all the equipment, but I have the luxury of trying the low input as well due to my preamp and extra cable I have lying around.  Thanks guys.

Integrating two subs seamlessly with the main speakers is a substantial challenge. The cabling part is easy compared to figuring out the cross-over points. It’s not something that’s done in one afternoon. If you don’t have a measurement software program, it can take a few months. Your ear needs to acclimate to the new low frequency source. My experience with phase is that it definitely needs to be dialed in for optimal integration. It’s a two person job. One person in the listening chair with the other adjusting the knob.

Good to know and I suspect you’re right with regards to finding the correct overlap point in frequencies with the full range speakers.  I do have an audiophile friend nearby who can help with this.  I also plan to purchase the appropriate measuring components to make it easier.  I may have a local company who specializes in this come out for a consultation as well.

I have two recommendations to make. The first is to go for at least two smaller subwoofers instead of one big sub. In most situations that produces a far more even response. See here for some reading: http://www.acousticfrontiers.com/20101029using-multiple-subwoofers-to-improve-bass-the-welti-devanti...
The second suggestion is to invest in a DSpeaker Antimode 8033 room equalization unit as well. This tightens the response significantly in both the frequency and time domain. With two subs this is even more effective because the equalization will be effective over a larger listening area. Subs have a bad reputation in audiophile circles, but this is largely due to the problem of the room modes that they excite. These not only produce peaks and dips, but they also linger on. People speak of slow subs, but it is not the subs that are slow, but the lingering room modes.

Excellent, thank you.  Funny you should mention Acoustic Frontiers.  That’s who I reached out to for a quote in order to handle the work of calibrating and positioning my subs and speakers.  They are local to me so if the consultation price is right that’ll work out really well.