gcinfl

Z461 said "High level outputs were tapped into from the head unit (The wires were in the rear hatch near the stock sub amp)." IOW, the rear amp drives the sub. The one under the glovebox apparently drives the two door and two behind-seat mid-ranges. The tweeters in the front pillars, according to the Clarion repair outfit (that I'm assuming had a wiring diagram) are driven directly out of the head unit.

I did some experimentation, knowing all of the above. When you turn the fader all the way to the front speakers, the sub is quieted. This tells me that the sub amp is only getting rear speaker inputs (both stereo channels of course). That means that if you want the front/rear fader to work on the head unit, I think you need to use the inputs to the other amp (under the glovebox), which does have front/rear, left/right, assuming the info from the Clarion repair depot is accurate.

Assuming all this to be true, it seems likely that the inputs to both Bose amps might be so-called hi-level outputs and that is why they had to use the level converter to feed the aftermarket amp.

I would think that the way the Bose is added in is that it merely accepts the four speaker outputs from the head unit and drives the four 6" speakers with the addition of the auto-EQ. Then I would assume the Bose sub amp located in the rear just looks at the same left and right rear channel speaker outputs from the head unit to drive the 10" sub. If so, the inputs to the sub amp lack the fading to drive a five-channel amp.

Hope this helps. Played with the "secret" power-up buttons a little more and still haven't figured out how to make it do anything once you get it into the "MA" or "CHG" modes. Need help!!

I bet the suspicious small wire goes to the hidden microphone. Someone please cut it and see if the auto-eq stops. Since it's an input to the auto-eq section, it should be grounded to avoid injecting noise into the auto-eq (although it probably wouldn't be any worse than it is with the mic hooked up).

gcinfl

The glovebox amp only powers mid-range speakers. It could do the dynamic-eq on just the mid-range frequencies. The sub amp could do the dynamic-eq on just the low (bass) freqs. It could be one mic or two. It is also possible that one amp does the dynamic-eq for both mid-range and bass freqs. Tracing the wires down from the amp(s) or finding a wiring diagram or schematic is the only way we're going to know.

I'm going to go to the garage right now and see how easy it is to remove that false bottom in the glove box and take a look at what's there. Will report back.

gcinfl

While I was playing with mine tonight, I was listening to FM in my garage. When I would adjust the TREBLE up, the BOSE SUB would jump up in volume in response!

I'm on a mission in my garage now. I just came back in to look at the photos again. I was expecting to find an amp under the glovebox. I didn't. After re-reading the post I see that it is "behind" the glovebox.

It's looking like I have to take off all the plastic from the seats back to uncover both these amps. The rear one is under styrofoam that appears to be held in by the strut brace cover and the side plastic/felt in the cargo area. I'm working on it.

gcinfl

I got to the rear amp and pulled one connector. It has 20 conductors! When you pull off this connector, which presumably connects this Bose amp to the head unit, none of the 7 speakers operate. This leads me to believe that this Bose contraption just controls the EQ and volume through the head unit.

I think the other connector has power-in and the sub-out because they are heavier gauge. I didn't disconnect them to see what happens.

Wouldn't it be a surprise to find out that all Bose adds is a 10" speaker, this amp to drive it, and the auto-eq function which just remotely controls the volume and EQ of the head unit?

Somebody needs to get their hands on a schematic or wiring diagram. Reverse-engineering these 20 signal conductors will definitely be the hard way to figure out how to disable the auto-EQ/vol.

gcinfl

Don't cut that suspicious wire--it's the antenna wire!

gcinfl

This shows the Bose amp still connected to its mounting bracket and turned upside down. You can barely see the blue connector, which is the 20-conductor (24-pin connector). The other connector uses 5 conductors. I'm guessing they are power, sub output and perhaps microphone?? I say this because those are the signals that would be unique to this Bose nightmare. I suspect the 20-conductor bundle is a standard set of signals to/from the head unit.

At the bottom left-hand corner of the photo you can see the small RF amp made by Clarion at the base of the antenna. There are two wires going to it, I presume a power and a very thin coax with the signal. These are the wires I said not to cut that are routed outside the harness bundles.

If I knew what the wire color codes were for the wires going to all the speakers, the head unit and the other amp, I might be able to start figuring out where these 20 wires go, from which I could make educated guesses as to what they are. Unfortunately I don't even have my multimeter with me, much less a scope to look at the signals. But I'll find one.

I do believe that harness could also supply all the signals a remote changer would need. I'm thinking Nissan will offer an MP3-capable changer to go in the extra slot behind the seat, like the one where the DVD drive goes for the nav system.

It would be nice to see if this 20-conductor connector is both present and disconnected in the non-Bose installations. Since the head unit doesn't put out any sound when this connector is disconnected, it makes me wonder what they do when the Bose option is not present.

gcinfl

If I just knew which one of these to cut.....