Vehicle: 2003 Infinity G35 Coupe with Bose sound system
Radio: Pioneer AVH-P3400BH (DVD receiver)

I have searched the forums for info, and have found some info in this post, post, and other posts. Unfortunately these posts don't completely answer my question on a technical level. I am a newbie and don't yet fully understand the audio technicalities. I was hoping someone could provide me with some technical info on the following question, please:

When should one use the RCA connectors versus the speaker output wires on the back of a head unit/radio?
If I researched this correctly, the RCA outputs are low level (NOT amplified) sound outputs and the HU's speaker output WIRES are amplified sound output. Correct?
So, if I am using a radio without an amplifier then I use the standard speaker output wires (high level), but if I am using an amplifier then I use the RCA outputs (low level) to an amplifier -- correct?

If I am keeping the Bose amplifier (most likely), should I use the head unit's RCA connectors or the speaker output wires?

If I am plan on replacing the Bose amplifier (at a later stage), should I use the head unit's RCA connectors or the speaker output wires?

I have purchased all of the following connectors: PAC ROEM-NIS2, Metra 70-7551 which includes the RCA connectors (low level), Metra 70-7550 which includes speaker wires for HU's amplified sound signal.

Currently I have my Pioneer radio connected via the HU's speaker output wires (not the RCA's) to the PAC ROEM-NIS2 harness adapter -- I connected them to the PAC ROEM-NIS high level speaker wires (not the low level). Is this correct? Or should I connect the HU's RCA outputs to the PAC ROEM-NIS2's low level sound inputs instead? Which works best? (Again -- I am keeping the Bose amplifier for now)

Thank you,

Cameron

 

Use the ROEM-NIS2 with the speaker-level outputs from the new headunit. That sounds like what you've got going on now.

Since you have everything out, spend a few bucks on RCA cables and connect them to the headunit and run them to the trunk so you dont' have to remove everything when you do get a real amplifier.