ok im running two L7's and a kx1200.1 amp, but on my old kenwood HU that i removed there were 2 places that i can plug in the RCA's and they were labeled "woofer" but on this, theres only one rca cable labeled woofer, the one next to it is labeled center, so would i plug my RCA's from my amp into center and woofer? heres the stats on the HU
also it says # 1-Subwoofer RCA pre-amp output (Variable)
# 1-Center Channel RCA pre-amp output (Variable)
what does "variable" mean?