anyone here using the ICBM with a SVS sub?

I just received my ICBM and and working thru the learning curve.

I am using it between my 3802 and amps. The rear centers are powered by the receiver.

I cant really hear a difference between the normal or special xovers. I have been going back and forth. Which should I use with a pair of 20-39's.

System info is:

Mains-Klipsch KG 5.2's
Center-Klipsch 2.2v
Surrounds-KG 4.2's
RC-KSB 3.1's

Thanks in advance

Earle