How to wire amp, with stock head unit

[Shawn323iC]

I'm adding an amp to my stock setup, to run a sub. I was going to take the signal from the rear speakers, but have some questions:

Should I take it before or after the amp? Which works better?

If before, I use RCAs and then hook up to the low level of the amp, right? Does the + go to the male part of the RCA, and the - to the "sheath" part of the RCA? Thanks!:

[jayhudson]

You must take it after the factory amp. The input to the factory amp is not a true line level signal. Be sure you have an amp with speaker level inputs. Jay

[Shawn323iC]

Can I splice the rear speaker lines after the amp, so that I can still have rears? Thanks!

[jayhudson]

Yes, that's exactly how to do it. Jay

[Seedster]

Originally posted by LUNI2NZ
Be sure you have an amp with speaker level inputs. Jay

not necessary...a lot of people (me being one of em) use line converters...10-20 dollar piece that converts from the signal wires (speaker level inputs) into RCAs....and yep....just spice em off of the rears (make sure to take it off the woofer and not the tweet)

[Shawn323iC]

Which will end up sounding better?

1) going from rear speaker outs -> line converters -> low level in on amp

OR

2) 1) going from rear speaker outs -> high level in on amp

I know Seedster know's what he's doing, so that's probably the setup I'll take...

[jayhudson]

Don't put anything in the signal path that you don't have to. Unless you have a real cheesy amp, the converters in the amp are superior to the external line converters. The conversion process has to happen somewhere. Either in the amp or before the amp. Jay

[Shawn323iC]

Sounds like a pretty good point to me. Cheaper too.

[PMPNX5]

I know this is an old thread, but I'm looking to do the same thing, and have NO IDEA what I'm doing. Does anyone have any pics to show me where to hook the converter into the rears? Thanks.