Has anybody installed a 4 ch amp and replaced the speakers? I want to know what kind of low input converter was used. When i installed my sub, i couldn't use the preamp lines to get a signal, I had to use the lines coming out of the stock amp.

 

Do a search, but I believe the concensus is, the lines going into the factory amp, is low level, so if you want to wire in some RCA's to them, and go directly into your amp (if it has adjustable gains) you should be good to go.

 

if it didn't work on the sub line, i don't know why it would work on the speaker lines

 

It should have worked on the sub line. Are you taking the lines from the input to the factory amp? again, these would be low level, not speaker level, so they would go into your amp in the RCA low level inputs, then adjust your gains accordingly. That is if your amp's input gain is adjustable.

 

yes i took it from the lines before the factory amp.. tried 4 different converters.. nothing...

 

You shouldn't need a converter really, just wire in RCA plugs.