Hi all, I'm REALLY hoping someone can help me...this is driving me crazy. I feel like I'm SO close...I have an '08 Chevy Tahoe with XM. I use the aux input on the front of the HU for my mp3 player, and I needed another input for my pnp Sirius unit. I read this post
about how you can hijack the audio signal from your XM module to your car's HU and use it like another Aux input. In that thread, the author says the sound is great, but he has an older car and there were only three audio wires out from the XM unit; left, right, and common. My car has four; left positive & negative, and right positive & negative.
I hooked it up to this 1/8" jack
with the two positives as left and right, and the two negatives combined to the common. It works, but it doesn't sound nearly as good as the aux port on the front of my radio. It's quieter and it kinda sounds mono-ish, like when you pull a headophone jack out half-way. I'm thinking the key lies in the fact that I have 4 wires compared to his 3.
I'm thinking (praying) I just need something like a "line-level adapter", or a "line-out converter" or something. Is there any way to tell what kind of signal the XM unit is sending to the HU; speaker-level, line-level, or something else? Am I on the right track, or should I bail on this project? I HATE doing that...