I have asked several times if the outputs from the BOSE HU (head unit) are speaker level (i.e. higher current) or line level and have received several answers stating yes and no using several different terms.

I want to get to the bottom of this.

G35 factory manual shows stock HU wired directly to speakers and the BOSE HU wired to the BOSE amp in the trunk, then to speakers.

There are several possibilities.

1) Stock and BOSE HU are identical except for minor features, etc and output a "speaker level" signal. In stock it goes to speakers, in BOSE it goes to amp, where is most likely signals across a high load, either in a single ended or differential configuration.

2) Stock HU outputs "speaker level" to speakers and Bose HU outputs a line level to BOSE amp in a single ended or differential.

Has anyone hooked up a multimeter to each positive and negative of a BOSE HU output channel?

With a test cd and a sine wave track the positive and negative should have the same abs. value but with different signs when the multimeter is in AC mode with respect to ground if it is a differential signal.

One of the wires will be approx, 0V if single ended.

Hook a brother up in any way if you can!

 

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