Yeah, that was me. I can say that reducing the A/V receiver's channel gain and increasing the SubMersive's amplifier gain did wonders for me. But I have a very old A/V receiver from the DVD days (Harman Kardon AVR 8500) and don't know how this would translate to the newer/current A/V receivers and pre-amps.
I have the original Klipsch RF-7, RC-7, and RS-7 that were bought new in 2003 and are alive and still kicking. I did have to replace one of the drivers/woofers on the RC-7 recently but I have been driving them extremely hard their whole life.
Thanks for the replies. It was just a general question but it is quite impressive that in order to get close to the Catalyst 12C from "big name" brands, you basically have to pay multiplies of the price of the 12C.