Okay... i've got a 92 SC3 with pioneer stock system...

installing a JL 10IB4 sub with a JBL BP600.1 amp...

I'm wondering if it would be best to use the LLC-RCA converter and use RCA cables to go to my amp... or if i should use the speaker-level inputs on my JBL amp?

I'm going for SQ... any suggestions?

 

Great question.
Try the speaker-level inputs on your amp first. The amp has internal circuitry that will convert the high-level signal to a lower-level to be used by the next internal buffer amp stage. This is generally preferable to using external passive circuitry to knock the signal level down, and should result in lower noise susceptibility.

 

thank you!

1 more question... after doing some research on my JBL BP600.1 amp.... someone suggested using splitters to connect to all the inputs (there's front-left/right and a rear-left/right) to improve performance...

should i connect to just 1 side from the sub-line output? or connect it from the rear deck speakers?

 

You only need to connect to inputs where you'll be using their corresponding outputs. If your sub is DVC, you'll need both L/R, if only SVC, then you only need one channel, and this can be a bridged output. Check your amp's manual.
If you were to connect to all inputs with splitters, in other words, run the same signal to front/rear left, and other to front/rear right, you'd need to combine the front/rear outputs to realize any benefit. Most amps are not set up to just parallel the outputs this way - the alternative is the internal bridging that you can do with most amps.