I'm bummed because my walls are prewired with two pair speaker wire for my subwoofer and now I can't use the line-level input to my SVS 20-39.

The Denon 3805 manual doesn't even mention speaker-level input, so I need help.

Should I route from the Denon to the sub using one pair in the wall and then route back the rest of the signal using the other pair?

Should I use the r/l front outputs or is there a better choice from the back of the 3805?

Most importantly, what will this do to performance? I can't remember what two pair wire is in the wall -- if it's decent 16/4 vs. 14/4 will that make a difference?

The rest of my set is Axiom 60 fronts, vp150 center, and QS8 surrounds.

Thanks so much,
Rob