SUB wire?

[dmatk315]

What is the SUB wire used for? I bought an aftermarket stereo, it has a FL/FR and RL/RR RCA output for and SUB wire. I am running 2 amps, 1 for my sub and the other for my speakers. I am using the FL/FR and RL/RR RCAs, there is no RCA for a SUB, just a SUB wire.

 

[JonSnell Electronic]

If you are talking about a car radio then the 'sub wire' powers on the sub amp upon request.

 

[Etocynned]

Hmm...never see that on a deck. Need more info