Last attempt before ditching it all.

[Jett]

I need some input regarding the Bose system in my NSX. So far I have had both door speakers and the floor sub replaced, and it is still doing the same thing, ie, static, popping, cutting out. I took it to a stereo shop and the tech there said that there is a bad amplifier that he says he found behind the factory head unit down in the console somewhere? I have never seen this component listed in any of the stereo discussions on NSXPrime. Is there such a component? Maybe someone knowledgable could post a list of oem components? If I don't get this straightened out this time I am going to remove the entire system and replace it with a simplified aftermarket system.

 

[steveny]

Mine does the same thing until it has warmed up for 5 to 15 minutes. I have replaced both door amps and still have the problem. If you find out what is up with yours please PM me.

 

[autobody tech]

does it have static only when driving, going over rough road, etc....?

 

[D'Ecosse]

I took it to a stereo shop and the tech there said that there is a bad amplifier that he says he found behind the factory head unit down in the console somewhere?

He's either B/S'ing you or found something that doesn't belong. There is no amplifier down in the console anywhere!
Your problem sure sounds like common Bose amplifier(s) problem - can you isolate it to one or other door, or to the sub or center?
Try adjusting your balance full left or right when you get the problem & see how that affects things. Where did you get the replacement amps? If from the tech that said it was "bad amp down in the console" you were definitely sold a bill of goods!

 

[Briank]

There is a relay that supplies power the speakers. If that is not working properly and is intermittently interrupting the power to the speakers you would get popping and other problems. I will look up where that relay is located let you guys know.

The relay is located in sub-relay box B which is under the hood by the right front headlight. The relay is the left rear one

 

[D'Ecosse]

Sounds like an excellent suggestion - hope that's it!

 

[Jett]

Follow-up

I didn't think there was such a component. The tech pulled the console plate and claimed there was some sort of amp which he tapped on and was able to get the stereo to play intermittently. I had sent out the doors and floor sub for repair and then reinstalled them myself. I still felt the floor sub was bad so I purchased another one which had been rebuilt, but that didn't improve things either. The tech claimed that the speakers and sub seemed to be okay, but that the problem was with this mystery amp. I think maybe he was tapping on something inside the console and was able to get intermittent play out of the stereo, so he thought the component he was tapping on was an amp, when it was probably some other relay of some sort. The stereo cuts in and out, is static-y, or just doesn't play at all. It never plays well, even for a short time.
I will check the relay that was mentioned; thanks for the suggestion. Any other input has been and will be appreciated.
I also installed an aftermarket antenna, which I write about in another post...

 

[D'Ecosse]

Maybe the connector plug at the rear of the head is not properly engaged, making partial, intermittant contact? There is nothing else to do with the radio in that vicinity.

 

[Jett]

More

I will check the relay and connector, although it would seem that if the tech had the console apart that it would have been properly reconnected. In the meantime, if I replaced the head unit with another head unit, is all the amplification taken care of at the sub or door speaker level? Does the head unit have any built-in amplification, or is it a "pre-amp" unit? I have considered obtaining a newer double-din type head unit w/ 6-cd changer, similar to an Acura TL or a Subaru WRX head unit and trimming the faceplace somehow.

 

[D'Ecosse]

Re: More

I will check the relay and connector, although it would seem that if the tech had the console apart that it would have been properly reconnected.

I would have thought if the tech had the console apart he could have identified & fixed whatever part he was tapping on rather than just putting it back together again & calling that "fixed"

In the meantime, if I replaced the head unit with another head unit, is all the amplification taken care of at the sub or door speaker level?

All amplification for the Bose speaker modules is done within the modules themselves - if you get a pre-amp only Head unit (or one that has both amplified & pre-out connections), that will work directly with the appropriate wiring-only connections.
If you buy a head unit with only amplified outputs, you will need a peripheral device to attenuate the signals to pre-amp levels to match the amplifier inputs in the doors & footwell speakers.

Does the head unit have any built-in amplification, or is it a "pre-amp" unit?

Pre-amp only.

 

[Briank]

Went through my electricial trouble shooting Manual looking for any thing that could be what the tech was talking about. I did think he was talking about the junction conector C471 that splits the power from the relay to each of the speakers but it is located on the right kick panel. I hope he was smart enough to read the label on the SRS control box.

 

[Hugh]

Bose Pre-amp outputs

Pre-amp only.

I haven't seen the back of the Bose head unit, does it have standard RCA jacks for the 3 pre-amp outputs or is there a proprietary harness that goes to the 3 amps with shielded cables?

Am I correct in assuming that it sends a full frequency response signal to the subwoofer amp and then a passive crossover splits the signal between the sub and the center channel speaker?
Anyone know the crossover frequency?

Thanks,
Hugh

 

[D'Ecosse]

Re: Bose Pre-amp outputs

I haven't seen the back of the Bose head unit, does it have standard RCA jacks for the 3 pre-amp outputs or is there a proprietary harness that goes to the 3 amps with shielded cables?

If only it were - unfortunately it's not so convenient. You will need to make up a harness that will plug between the head & the stock NSX harness - you can find details of how-to & where to find the parts Here

Am I correct in assuming that it sends a full frequency response signal to the subwoofer amp and then a passive crossover splits the signal between the sub and the center channel speaker?
Anyone know the crossover frequency?

I'm not exactly sure what it does - it is probably safer (& frankly easier) to just use the front channels (as wired per the link above), run an RCA pair to the amp then split via Y connectors just before the amp to give you the sub channel inputs; then just use the amp filters to control your frequency response as desired.

 

[Briank]

There are no RCA conectors on the head unit. There are 4 signals that come out of the unit, left, right, center and Sub. The left and right go each to the left and right door speakers and the center and sub are combined at the subwoofer amp. The single output of the subwoofer amp goes the the sub speaker and the center speaker which has a cap. that I assume filters or blocks the low feq.

 

[Hugh]

Since these are line level (pre-amp) outputs that run from the head unit, I assume they are shielded wires that can have female RCA jacks attached to them. Is this a correct assumption?

 

[D'Ecosse]

Since these are line level (pre-amp) outputs that run from the head unit, I assume they are shielded wires that can have female RCA jacks attached to them. Is this a correct assumption?

They are not - I recommend you see the reference thread from my post above & do it that way - you will preserve the integrity of the original wiring harness & also end up with a clean job.