Need help with new head unit for '98 Maxima with Bose
 

Hey all, I found a time capsule '98 Maxima SE with 56k miles last year for my daughter to drive and now that she's bought herself a Cube, I'm driving the Maxima for a couple of years until my middle boy hits driving age. I cannot survive with a factory CD deck with no AUX input so I purchased a Sony double-DIN CarPlay unit from Crutchfield along with a Scosche CNN03 wiring interface that's supposed to bridge the gap between the onboard amp in the Sony and the amps in the Bose speakers. If you're not familiar with the Scosche adapter, it has 4 adjustable pots to tweak the output levels between deck amp and speaker amp. BUT...I've found it impossible to find an adjustment point where I get sufficient volume out of the system without serious distortion.

I called Scosche and they suggested I try connecting directly from the deck to the speakers. My assumption was that was impossible (deck amp vs speaker amps), thus the adapters they sell. Has anyone tried this approach?

Another alternative is an adapter that goes from the RCA pre-outs on the deck to the factory speaker harness (both Scosche and Metra make such an adapter). Has anyone tried this approach with any success?

I don't want to sink a bunch of money into a high-schooler's car and tear out the factory Bose speakers and wiring. I'm really hoping there's a way to get acceptable sound quality between the aftermarket head unit and the factory speaker system.

Any help appreciated.