Best way to feed a rear sub?

I'd like to install a rear sub on my HT setup. Currently using two Citation 7.4 passive subs on the front powered by a Citation 5.1 preamp and a couple of Marantz monobricks. I want to setup a sub using the same (Citation 7.4) sub and monobrick about 30ft away from my preamp on the rear sub output of my preamp. Since this is a passive sub, and I'm powering it with a monobrick amp, what is the suggested way to feed my sub? Should I use decent RCA interconnects and place the monobrick with the sub, or should I have the monobrick with a short interconnect near my preamp and use 8 gauge speakercable to feed it?

I use the built in 80hz active crossover in the preamp to feed my subs, but don't know if you lose more low fequency response with line-level or amplified level cables when feeding 30ft of cable.

It's probably better to opt for a long run of speaker cable as opposed to a long interconnect. Monster does sell long single runs of their M351 subwoofer interconnect for subs with built-in amps. But since you have an outboard amp and crossover you should probably keep the monobrick closer to the pre/pro.

I've also read that placing a sub in the back run from the LFE output of the pre/pro doesn't always work well. I forgot why, but that's something you might want to look into. And that if you place the sub in the back it should be getting it's signal from the rear surround output. So I guess you would set the rear surrounds to "large" and use a crossover to split the signal between the rear surrounds and their subs.

I'm sure other more informed forum members can expound on the few points I bring up, or even rebutt them. I recall reading about this subject in Widescreen Review, Sound & Vision, and in this forum.
i respectfully disagree with gunbei. it's almost always better to use short cables and long interconnects, particularly if you can utilize xlr ic's between fully-balanced components.

BTW, what is a "monobrick"? half a monoblock? whatever, i like your word; can you imagine pink floyd singing about "just another block in the wall"? -kelly
Cornfedboy makes a good point. Reputable manufacturers such as REL utilize built-in amps and crossovers. Depending on installation limitations, the sub may have to be a quite some distance from the source. The only choice would be to run a long interconnect.

I think the monobrick reference may be to the Marantz MA500 and MA700 mono amps which ressemble big, long bricks.

I stand corrected. :)