I just went through what you are going through and if you check out my post you will read a lot of different things. As you, I received the first the day before the 2nd and got it integrated pretty easily. Adding the second proved challenging for me. I was able to talk to customer service with REL and he assured me that when it comes to phase once you have one set correctly the other sub will be set the same. Get one tuned in, unhook the Speakon and hook up the other and get it dialed in. Don't try to limit yourself then it comes to setting crossover and gains and they may not necessarily be the same; one subs placement may require a little more gain. I have one side of the front wall that opens into another room so it's not ideal. My subs are placed asymmetrically as one is placed in a corner angled as REL suggest and the other is placed inside my right channel bookshelf over a foot from the wall facing straight out. It's very listenable now and I know with some minor adjustments I'll get there. I'll help any way I can if you want to PM me.
