You can use a 2x4 HD from miniDSP. You can route the full frequency range to your amp, and then only do 80 yards and below with a low pass filter to correct your subs. If you're concerned about that unit affecting the quality of your audio, you could also put it in line between the subs and the...
Glad you are enjoying it John. If you're ever up for it, we could ship each other our amps for kicks. I'll ship you my M3a-3000S and you ship me the emotiva. We can compare notes!