Yep, turns out I was a dumbass. I was getting everything setup to test and call Ron and eyeballed my MiniDSP. I had recently taken my bumpbox out of the signal chain to see if my receiver could output a high enough signal to fully drive my EP4000 and never reinstalled it. I had also maxed out the subwoofer trim level when I did that. My MiniDSP was clipping the signal. I took it out of the signal chain and all is well.
While I feel like the world's biggest idiot, I'm happy it now works as it should. And now I can't wait to get the crossovers and see how the fullrange sound is!
Thanks again Ron and Wayne for your willingness to help out!