Alpine INA-W910 AUX Problems

[alanwu07]

Hi,

I purchased my 2010 Touring used with an Alpine INA-W910 installed. The AUX seems to have some issues as when I put any sort of music through it, it sounds terrible. Not the alternator whine or static kind of bad but completely missing the bass and muffled vocals and barely audible high-end. I'm not sure if this has something to do with any grounds but the audio is perfect when I play music through the USB or radio.

I recently purchased a ground loop isolator and it has gotten rid of most of the problem, but the audio is still noticeably worse than USB even though I'm playing both through my Nexus 5 (USB and AUX-in, same MP3 songs, all in 320kbps if that makes a difference).

The audio after the ground loop isolator is better in that it has bass and you can hear the vocals clearly, but there is still a bit of noise. Anyone have any idea what this could be? I've done a bit of research and it may be just the ground? I'd like a second opinion on this before I take it into a shop for them to check it out. Thanks!

[Fountainhead]

Hi Alan,
could be your 3.5mm cable isn't right for the pinout of your Nexus 5 output jack. Just a WAG not knowing anything else about the Alpine Aux input pinout. Since your Nexus is not grounded to anything you shouldn't need a ground isolator? If you have it plugged into a charger try removing that then plugging into the Aux input.
I know iPhones have a 4 pin headphone output, 1 is mic, 1 is ground reference *not chassis ground but a null reference point, and then L & R signals referenced to that null point, which is a ground reference to the L, R, and Microphone input but not to the chassis.
Your Nexus I know has a similar output configuration with the mic and ground reference pins swapped ( in relation to the iPhone pinout). I would google that and see what cable you need. I know on most of them the typical L, R, Gnd 3 pin configuration type 3.5 mm cable usually works.
good A-B test is to try another phone, any of them should work with a L, R, Gnd, Ring tip sleeve cable.