After reading old posts here, I've read a lot of conflicting info.
Is it true that the 03 G35's Bose and non-Bose stereos use the same exact HU?
Is it also true that this HU has both low and speaker level outputs?
If so, it is possible to hook up different front door speakers directly to the HU's speaker-level outputs, bypassing the Bose amp?
Can someone explain to me how the HU's low level signal is balanced using only 2 wires whereas true balanced connections require 3 wires (2 hot and 1 ground)?

 

Can someone explain to me how the HU's low level signal is balanced using only 2 wires whereas true balanced connections require 3 wires (2 hot and 1 ground)????????????????????? WHAT? Where did you hear this? This makes no sense to me
The only difference between the bose and the non bose is the amp in the trunk
head unit only has high level out and amp translates the signal to the speakers.
you should be able to swap in new speakers without much of an issue. people have been doing it on here quite a bit, but refrain from trying to pump up the bass and treble settings

 

Are you saying you never heard that the HU had balanced low-level outs or that balanced requires 3 wires (1 positive phase, 1 negative phase and 1 ground)?
If its true that the HU's are the same, does the non-Bose stereo have an amp somewhere or does the HU power the speakers? How many watts is it?

 

the three wires thing - never heard of that except on common ground systems
Head unit powers the speakers. It's likely the same as every other factory deck 7-12 watts rms - aftermarket decks will output 15-22 watts rms

 

There is a difference between the Bose and non-Bose HUs. the Bose HU outputs a low level signal to the Bose amp which amplifies it and sends the signal to the speakers.. The non-Bose HU outputs a speaker level output from the HU that is sent directly to the speakers.

Whether the low level signal is balanced or not, I don't know for sure. But you can feed the low level Bose HU output directly into the RCA input of an aftermarket amp just by splicing an RCA end onto the Bose HU output wires before they enter the Bose amp.

 

Yep, this confused me too. All I know is that I used the existing low level wires and spliced RCA plugs on them but it induced alot of noise. I ended up running new RCA cables instead...much better, no noise at all. Keep in mind that I also had changed out my headunit to an aftermarket one. It may or may not induced any noise using the original factory headunit.

 

The schematic for the bose system does show a 3rd wire for the shield connected to the HU's ground. This is on my 04X anyway. Page AV-14 is the factory service manual. The base system (Page AV-11) does not have this.

You can also get a balanced system with two wires if the reference is grounded internally to the amp. Even if you don't call this "true" balanced, it can still be differential and give you the same benefits of common mode noise rejection.