iboost

Yup. The audio pilot/auto-adjusting volume still works. I wish that "feature" had an option where we can disable it, but alas we're stuck with what we got: MUCH less bass and a system that automatically adjusts sounds relative to cabin noise...

-iboost

jelledge

Yeah, I would say that after the amp replacement my audio pilot barely does anything now. I notice it a little more with two people in the car and the radio is playing - the volume seems to change more drastically for whatever reason.

It was that way before the amp replacement only worse. The radio was so bad with two people in the car I could not even listen to it due to the boomy bass. Now I got no bass

I have filed my complaints with Nissan and Bose. I guess we will just need to keep beating on them until something is done - right.

znetuser

Jason,

Thanks for the pics. It's nice to have a visual record of those components and locations. It's unfortunate that the experimentation didn't yield more favorable results. At least we tried to effect a fix.

About the Bose amp pics:

The absence of massive semiconductors and huge heat sinks is not cause for alarm relative to their power output capability. In all probability these are pulse width modulated switching or Class D amps. Switching amplifiers are very efficient. They can produce large amounts of power into low impedances while dissipating very little heat themselves. Bose has been known to use switching power amplifiers in their auto sound systems. The speakers that Bose has used with car switching amps tend to be lower than normal impedance, on the order of 1 ohm as opposed to a typical 4 ohms. The advantage is that much higher power can be delivered into the lower impedance, (resistance), with lower voltage swings. (Power into a resistor is: watts = (RMS Volts squared)/Resistance). So you can see that if these speaker drivers are replaced with typical after market 4 ohm drivers, (although higher quality), that the power delivered by the amps will by only approx. 25% or -6DB relative to the OEM Bose 1 ohm drivers.

I'm going to live with the, (non-TSB'd), Bose for now. Actually even FM is not that bad, particularly at higher levels and the CD is better yet. It would take thou$and$ for the car to sound anywhere near my in home audio. I'll avoid details but, (house), I have over 1600 watts of power amps for a 5 channel system where my main L&R front speaker systems are VMPS Super Tower Rs with cabinets weighing 160 lbs. each, about 10 cu. ft., with two 15" and one 12" woofer, two 5.5" ferro fluid mid ranges, two 1" dome 200 Watt ferro fluid tweeters, a dual element ribbon super-tweeter and an upward fired .75" pezio on top of the cabinet. Not a whole lot'a cars can sound like this in house system can. I can play at over 110 DB SPL while keeping the power amps out of clipping!

qirex

dude...you seem to have a fair amount of knowledge regarding amps. Since you also have *reasonable* expectations of what the car can/will sound like w/o dumping $$$$$$ (and it IS dumping) into it I URGE you to get "the fix" done. If you think its *okay* for what it is now, you'll love it after the fix. Big deal if you cant put the bass up to +5 and hear the amps clipping.

SunsetZ

Where is the main amp located, is it in the trunk as well?

onecoolee

Ok, since any previous testing has not really resulted in any concrete fixes...has anyone tried to prevent the mic from picking up any road noise (what it was designed for)? Since the Audio Pilot technology used in the Z is not something we can turn off, what if we just cover the mic up ? You cannot disconnect it, as it is a condenser type mic and essentially is providing constant feedback to the amp (according to the FSM, the mic connects directly to the main amp). I assume that the mic is essentially its own circuit, probably comprised of a cap and resistor (RC circuit with changing impedance), like most condenser type microphones. If the sound entering the mic never changes, it shouldn't have any effect on the system...right ? It will still be connected, so the amp will still be receiving the proper loading at the mic input, but the effect of the mic should be very minimal, as long as its protected from any changes in sound level (road noise, etc). I can't think of any reason why keeping the Audio Pilot mic connected, but actually keep it from "hearing" anything would not improve our boomy bass and automatic frequency level adjustment problems. I know its not safe to disconnect it altogehter, and Nissan should have had a means of defeating the mic, but while we wait until 2004 for Nissan to come up with a fix, we need to figure something out. My Vin is in the TSB range, but I don't want to lose all of my bass or especially the controls over my bass and treble.

Is anyone willing to try this fix who already has easy access to the Audio Pilot mic (IE steering wheel ripped apart) ? I would suggest putting a piece of foam or several layers of tape over the mic input to muffle the sound enough where it has no effect on the system. I honestly feel the best fix is new speakers, 2 new amps, and a new sub, but maybe this will get most of us by until we can stockpile the cash for something nice.

If anyone is willing to give this a shot, please post any results here, and if I happened to miss a post where this was tried already...sorry.

Have a happy new year...

tbob

Check out the following thread:

https://my350z.com/forum/showthread....threadid=11681

A lot of the experiments you suggested have been tried. Most of the stuff is further down than the opening posts though.