Hey which sounds better?

 

rca

 

RCA is supposed to give you the cleaner sound.

 

Okay. Do you get higher output with the speaker level inputs, though? Is that the reason you get more distortion? I guess I should tell you I had a Kenwood KAC-207S Receiver hooked up with the RCA's and I think I was still getting distortion on some stuff, it just seemed that it was less noticeable and it went away when I turned the bass down, but I guess it would seem to go away as I turn the bass down cause it becomes harder to hear it at all, then. Also, when I had the amp (Kenwood KAC-719) hooked up with its speaker level inputs, the distortion was not constant. It was certain music, like string bass in jazz and also string bass in classical music. When it's supposed to go bum bum bum it'll go bu-thunk bu-thunk or something or other. Sorry about the poor onomatopaeia.

 

THIS MAY ANSWER SOME OF YOUR QUESTIONS. http://www2.carib-link.net/~ilaurenc/goodamp.htm

 

RCA whenever and wherever possible!!

 

The problem with speaker level outputs is this:

You start with a pre-amp signal that goes to some amp (either an external Bose amp or an amp in the HU).
Then, you amplify that signal in the amp so that it becomes powerful enough to drive your speakers.
But, instead of running this amplified signal to the speakers, you run it into a speaker level line output converter (LOC) box.
The speaker level LOC now cuts the signal strength way down to pre-amp levels again.
Now you run this pre-amp level output from the LOC into your aftermarket amp.
Then you run speaker level outputs from your aftermarket amp to your aftermarket speakers.

Bottom line, this setup yields lots of distortion because of all the amplification and signal reduction stages. Do a search on LOC or Line Output Converters and you will find some links to devices that can adapt your OEM Bose HU to an aftermarket amp! Good luck!