NSX after market w/ stock head issue-help

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20 May 2002
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262
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maumee,oh,usa
I have an aftermarket amps, speakers, sub, etc. (Bostom accostics) - anyway with the aftermarket stereo it worked fine. I wanted the stock look so I put the stock head unit back in. It sounds great when I turn it up half way but if I turn it up anymore than that it just gets distorted. Do I need to boost the signal? Any help would be great! Thanks.
 
the best way to reduce the distortion is to increase the size of the Amp. Most radio's are designed to perform well up to 1/2 volume. after that the level of distortion produced by the pre-amp increases...

At first glance I would say you need more power at the Amp....that way 1/2 volume is loud enough for you.
 
The distortion only comes out of the drivers side but not so much out of the passenger side. Not sure what that is all about.

It sounded fine with the after market head unit.

Thanks!
 
As someone who re-did his sound system last year and wrote about it for the NSXDriver magazine last year, my best advice is that before you go messing around, make sure you understand your current setup. I don't know how well you know the OEM system but the head unit basically has no amps and the outputs are at pre-out levels. That signal goes to the doors where the BOSE amps provide the power to the speakers. So you need to understand whether the previous owner's 'head unit' is just a 'head unit' with no amps or whether you also have an amp (other than a sub amp) and they removed the door units (combo amp and speaker) and replaced them with just speakers. If you still have the OEM BOSE amps in the doors, they are probably in need of repair .. which is a common problem as the capacitors in the amps degrade over time.

If you just changed the head unit but ran the output through an aftermarket amplifier before going to the BOSE amps in the door, then you're probably getting distortion from trying to amplify it twice.
 
Hey Glow,
Could be a few different things. How is the OEM stereo connected to the amp? You could have a phase problem if the boston stereo hooked up a different way then the OEM. In other words, you need to find out if they switched the leads to make the aftermarket stereo work. Also most amps have a gain that can be adjusted. Maybe the OEM stereo needs more gain on the amp then the aftermarket one did.

Mike
 
Hey Glow,
Could be a few different things. How is the OEM stereo connected to the amp?

Yes, answer this question first.

Each combination of headunit to amp requires a different wiring setup to make it sound right.
You'd need swap between these two to get it right. Note the RCA plugs when using a factory headunit to aftermarket amps. Did you connect the factory headunit using RCA cables?
factoryhead-after.jpg

after-after.jpg
 
Last edited:
Yes, answer this question first.

Each combination of headunit to amp requires a different wiring setup to make it sound right.
You'd need swap between these two to get it right. Note the RCA plugs when using a factory headunit to aftermarket amps. Did you connect the factory headunit using RCA cables?
factoryhead-after.jpg

after-after.jpg


With this set up are you saving that you can connect a after market headunit to the stock speakers? My system sends a lot of static and popping at low volume:confused:
 
With this set up are you saving that you can connect a after market headunit to the stock speakers? My system sends a lot of static and popping at low volume:confused:

With an aftermarket stereo, there are two ways to wire them to the NSX Speakers. One way is correct and the other way will cause the speakers to be overloaded (possibly causing static and popping).

The correct way to connect an aftermarket headunit to factory speakers is to use this plug:
afterhead-factoryamp.jpg


The white plastic harness portion connects to the NSX's factory plug. The lose wires are then connected (soldered or crimped) to the headunit's wiring. The RCA plugs will connect to the back of the aftermarket headunit. It is VERY IMPORTANT that the OEM speakers are receiving their signal from the RCA plugs and NOT from the headunit's internal amp. The correct installation of an aftermarket headunit to OEM speakers will bypass the headunit's internal amp and only get the signal from the "PreOut" cables in the back.

The "incorrect" method is if you have the headunit connected to the OEM speakers via the standard +/- wiring, then you are double amplifying the signal (once by the Headunit and once by the OEM speakers internal amps). This could be the source of your popping & static.
 
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