Over time, there have been many threads about the NSX sound system; why isn't it working?; how can I fix it?; how can I upgrade it; etc. There is some content in the Wiki about it but some of it is dated and doesn't deal with some of the things that are available today so I had intended to write an updated Wiki article about it. However, since the Wiki is currently locked down, I thought I'd use the same approach as Yinzer did recently on his "buyer information" thread, and create a thread dedicated to the Stereo System. At least, that way I can add to it over time and point to other related threads. Disclaimer: I'm not a guru stereo installer but I did graduate as an electronics engineer a few decades ago; have gone through the amp refurb route; and relatively recently converted to an aftermarket setup, so I have some practical knowledge which I wrote about and which appeared in an issue of NSX Driver.
All comments welcome.
How It’s Designed
The NSX OEM stereo system was designed by BOSE and follows their standard design of a central head unit (which has no amplifier functions) and a number of individual speaker enclosures (which consist of a speaker and integrated amp). BOSE claims that the benefit of this design is that they can individually tune each speaker/amp combination to its location and the individual acoustics of the vehicle. The downside is that it is more difficult to enhance or replace with aftermarket components.
In the NSX, there are 3 speaker/amp enclosures and they are located in each door, and one in the passenger footwell where it is part of the subwoofer enclosure. There is actually a fourth speaker which centrally mounted between the seats near the armrest which serves as the only ‘rear’ speaker. It does not have an integrated amp but is driven by the amp in the subwoofer enclosure.
Note that the NSX stereo system only has two channels (L and R) and the amp in the subwoofer enclosure merges the two channels and sends the lower frequencies to the sub and the higher frequencies to the center channel. The speakers only have a single low impedance (one or two ohm) speaker (no separate tweeter/midrange) and it is presumed that any crossover circuitry is built into the associated amp. Because the speaker wiring only has to carry low level ‘line out’ signals, it is not large diameter and may not be capable of carrying the heavier currents in upgraded systems where the wiring must not only carry the larger voltages of speaker outputs but also the higher wattage levels of newer aftermarket amps. The BOSE design also means that the amps in the speaker enclosures need +12V/Gnd wiring (part of the NSX wiring harness) that isn’t required for centralized amp designs.
My Sound System Sounds Like Crap – What’s Wrong
In 90%+ of the cases, the problem is with some of the electronic components in the amps called capacitors which fail due to heat or other factors. If you were to open up an amp, there are many of these capacitors and failed ones typically bulge and/or leak out onto the circuit boards. The result is that they are no longer able to perform their electronic function and there is typically a loss of certain frequencies (maybe most) and/or a hissing noise or lack of volume. Note that in nearly all cases, the bad sound is due to the amps and not the speakers which rarely need replacing.
The good news is that there are a number of companies (including NSXPrime user BrianK) who can refurbish the amps by replacing the defective capacitors for about $100 each. This should restore the system to the same level of quality as it left the factory with. For some people this is sufficient but others feel the original sound volume/quality is inadequate by today’s standards and insist on upgrading or replacing it.
In a very, very small number of cases, the head unit can be the cause of problems and it can be rebuilt as well (it has circuits with capacitors too). Unfortunately, there is no reliable way of telling if the problems are with the head unit but from past history, you’re better off to first fix the door and sub amps first before sending the head unit out. You can use the head controls to throw all the audio to the left or right door to see if there’s a difference but after a while, we have all faced this problem and if you’re doing one amp, you might as well do them all. If there is absolutely no sound from the center speaker, the sub amp is probably toast. If you have issues with AM but not FM (or vice-versa), it’s probably an issue with the power antenna. If you have an OEM CD changer in the trunk but you can’t get any CD’s to play, that’s a whole other topic for discussion.
If you do plan to send out the amps for refurbishing, there are good instructions on how to do this in the NSX Wiki at: http://nsxprime.com/wiki/Bose_RR
What Are My Upgrade Options?
This depends on why you’re wanting to upgrade. The reasons are typically as follows:
1. Keep the stock head unit but add an iPod/MP3 player interface
2. Keep the stock head unit but migrate to a better, more reliable amp
3. Replace the head unit with a double DIN one with video/GPS/etc and integrated amp
1. Keep the stock head unit but add an iPod/MP3 player interface
If you have an existing OEM CD changer in your trunk, this is a great solution whether it is still working or not. The original changer did not support CDs with MP3 on them so a number of people successfully upgraded to Alpine S634 models which served the purpose for the times but moving to an iPod/iPhone/MP3 player interface is the way to go today. Science of Speed sells one that plugs into the existing CD changer wiring and provides a connector that you can install in the armrest, ashtray location, or wherever. This unit allows some minor control via the head unit but playlists, folder display, etc has to be done by the iPod/iPhone/MP3 Player.
2. Keep the stock head unit but migrate to a better, more reliable amp
This option is going to cost more (probably $500+) and will require more DIY effort because you need to replace the distributed amp BOSE design with a central amp. In addition to the cost, there is the issue of where to put the amp, and the associated issues of how to provide sufficient power to it; how/where to best run audio and speaker cabling; etc.
Although people have installed amps in the glove compartment (loss of storage space and heat issues) and in the trunk (more difficult and longer audio cable and speaker wire runs but close to power and ground connections), the easiest place is probably behind the drivers seat if you can stand to lose a bit of legroom. Behind the passenger seat might also be a location but the passenger legroom is already somewhat compromised because of the sub in the footwell. With the introduction of much smaller Class D amps, people have also suggested locating them under the seats but this space is extremely limited and I’m not aware of anyone actually doing this.
One of the benefits of locating the amp behind the drives seat is that it is not very difficult to run the amp power cable through a grommet in the firewall behind the driver’s left shoulder and into the engine compartment where it can be easily connected to the electrical block where you would also jump start the car. There are also a number of convenient locations to ground the amp on the inside of the firewall where most of the cars other electrical components are installed. This results in very short runs for both the power and ground connections as well as all of the amp audio connections which are easily run through the center console to the head unit and to the speakers.
Note that Science of Speed also sells wiring harnesses for both OEM and non-OEM applications which can simplify the wiring. This allows you to access the Left and Right channel line-out connections from the head unit and use them as line-in inputs to the new amp. The new amp speaker outputs can then be sent back to the wiring harness where they would travel over OEM wiring to the doors. However, because these are speaker-level, not line-level, you have to open up the door enclosures, bypass the BOSE amps, and connect directly to the speakers which is relatively easy to do. Alternatively, you can just replace the existing speakers with newer better ones. SOS sells replacement mounting kits which can be substituted for the OEM enclosures.
Re-working the sub can be a similar process. You could keep the existing BOSE amp/sub combo but most people will want to have the new amp drive it as well. Although the sub is small, it generates decent base if driven by a good amp try it before spending money on a replacement. You can always replace it easily later if you use the new amp to drive it now. In order to do so, you will need an amp with more than just the 2 channels for the doors but you can easily find 4 and 5 channel models where the extra channel(s) can be bridged or directly drive a sub. Ideally, they will also allow the option to internally bridge the L/R inputs to the extra amps but that’s not difficult to do if they don’t. As with the door enclosures, you’ll need to bypass the BOSE amp.
One issue with this approach is that, as was mentioned earlier, the OEM wiring to the doors is limited in it’s power handling capabilities so don’t try to put a gazillion watts through them. Also, if you do use the existing BOSE speakers, remember that they are very low impedence so turn the amp volume WAY down before testing them otherwise you may be replacing them soon. I also used the OEM sub but instead of using the factory wiring, I ran heavier speaker cable to the amp in case I choose to replace the sub in the future.
3. Replace the head unit with a double DIN one with video/GPS/etc and integrated amp
If you choose to go this way, the electronics piece may be simpler if the new head unit contains an integrated amplifier function. You’ll have the problem of where to get adequate power but you won’t have worry about where to put it and the cable runs will be much shorter. However, you will still need to bypass the BOSE amps in the doors and at the sub and have some of the same issues as in #2. The other more significant issue is in getting an acceptable double DIN replacement for the center console and getting the installation to look good and not have a lot of glare. Also, have a close look at the existing console design which narrows as it goes back so something you think may work on the face of the console may not have enough clearance for the deeper part of the unit.
Other Considerations
This is the first version of this thread and doesn’t yet include some other issues people may have with the existing OEM sound system such as:
• Options to connect various phones/players
Here's the 'condensed version' (but still huge thread) on iPod/iPad adapters: http://www.nsxprime.com/forum/showt...for-your-oem-NSX-Stereo-the-condensed-version
Here's one for Android: http://www.nsxprime.com/forum/showthread.php/164577-Android-Phone-to-OEM-Stereo
Here's one for Bluetooth: http://www.nsxprime.com/forum/showt...uetooth-audio-gadget-for-those-with-mp3-jacks
Here's one for AUX input: http://www.nsxprime.com/forum/showthread.php/142287-AUX-Input-for-OEM-Acura-Bose-Radio
• Ability to add equalizer and/or crossovers
• Sub upgrade options
• Other sound system issues such as:
o Display orange tint/brightness issues
o Antenna issues
o Loose/worn head unit knobs
• Soundproofing - try this thread on Dynamat: http://www.nsxprime.com/forum/showthread.php/151989-please-share-dynamat-door-install-pics
• OEM head unit connectors
Here's probably the original "Double Din" thread - lots of pages: http://www.nsxprime.com/forum/showthread.php/64651-Double-DIN-video-head-unit-thread
Builds/Inspiration:
1. http://www.nsxprime.com/forum/showthread.php/161234-check-out-this-center-dash
2. http://www.nsxprime.com/forum/showthread.php/161990-Pioneer-in-dash-double-dins
3. http://www.nsxprime.com/forum/showt...tion-amp-Double-Din-Modification-Lots-of-pics!
Center Console Replacement Options (not exhaustive - just some links I've squirrelled away):
1. http://www.nsxprime.com/forum/showthread.php/173522-Carbon-Fiber-Center-Console
2. http://www.nsxprime.com/forum/showthread.php/177941-Just-a-tease-Full-carbon-console-double-din
All comments welcome.
How It’s Designed
The NSX OEM stereo system was designed by BOSE and follows their standard design of a central head unit (which has no amplifier functions) and a number of individual speaker enclosures (which consist of a speaker and integrated amp). BOSE claims that the benefit of this design is that they can individually tune each speaker/amp combination to its location and the individual acoustics of the vehicle. The downside is that it is more difficult to enhance or replace with aftermarket components.
In the NSX, there are 3 speaker/amp enclosures and they are located in each door, and one in the passenger footwell where it is part of the subwoofer enclosure. There is actually a fourth speaker which centrally mounted between the seats near the armrest which serves as the only ‘rear’ speaker. It does not have an integrated amp but is driven by the amp in the subwoofer enclosure.
Note that the NSX stereo system only has two channels (L and R) and the amp in the subwoofer enclosure merges the two channels and sends the lower frequencies to the sub and the higher frequencies to the center channel. The speakers only have a single low impedance (one or two ohm) speaker (no separate tweeter/midrange) and it is presumed that any crossover circuitry is built into the associated amp. Because the speaker wiring only has to carry low level ‘line out’ signals, it is not large diameter and may not be capable of carrying the heavier currents in upgraded systems where the wiring must not only carry the larger voltages of speaker outputs but also the higher wattage levels of newer aftermarket amps. The BOSE design also means that the amps in the speaker enclosures need +12V/Gnd wiring (part of the NSX wiring harness) that isn’t required for centralized amp designs.
My Sound System Sounds Like Crap – What’s Wrong
In 90%+ of the cases, the problem is with some of the electronic components in the amps called capacitors which fail due to heat or other factors. If you were to open up an amp, there are many of these capacitors and failed ones typically bulge and/or leak out onto the circuit boards. The result is that they are no longer able to perform their electronic function and there is typically a loss of certain frequencies (maybe most) and/or a hissing noise or lack of volume. Note that in nearly all cases, the bad sound is due to the amps and not the speakers which rarely need replacing.
The good news is that there are a number of companies (including NSXPrime user BrianK) who can refurbish the amps by replacing the defective capacitors for about $100 each. This should restore the system to the same level of quality as it left the factory with. For some people this is sufficient but others feel the original sound volume/quality is inadequate by today’s standards and insist on upgrading or replacing it.
In a very, very small number of cases, the head unit can be the cause of problems and it can be rebuilt as well (it has circuits with capacitors too). Unfortunately, there is no reliable way of telling if the problems are with the head unit but from past history, you’re better off to first fix the door and sub amps first before sending the head unit out. You can use the head controls to throw all the audio to the left or right door to see if there’s a difference but after a while, we have all faced this problem and if you’re doing one amp, you might as well do them all. If there is absolutely no sound from the center speaker, the sub amp is probably toast. If you have issues with AM but not FM (or vice-versa), it’s probably an issue with the power antenna. If you have an OEM CD changer in the trunk but you can’t get any CD’s to play, that’s a whole other topic for discussion.
If you do plan to send out the amps for refurbishing, there are good instructions on how to do this in the NSX Wiki at: http://nsxprime.com/wiki/Bose_RR
What Are My Upgrade Options?
This depends on why you’re wanting to upgrade. The reasons are typically as follows:
1. Keep the stock head unit but add an iPod/MP3 player interface
2. Keep the stock head unit but migrate to a better, more reliable amp
3. Replace the head unit with a double DIN one with video/GPS/etc and integrated amp
1. Keep the stock head unit but add an iPod/MP3 player interface
If you have an existing OEM CD changer in your trunk, this is a great solution whether it is still working or not. The original changer did not support CDs with MP3 on them so a number of people successfully upgraded to Alpine S634 models which served the purpose for the times but moving to an iPod/iPhone/MP3 player interface is the way to go today. Science of Speed sells one that plugs into the existing CD changer wiring and provides a connector that you can install in the armrest, ashtray location, or wherever. This unit allows some minor control via the head unit but playlists, folder display, etc has to be done by the iPod/iPhone/MP3 Player.
2. Keep the stock head unit but migrate to a better, more reliable amp
This option is going to cost more (probably $500+) and will require more DIY effort because you need to replace the distributed amp BOSE design with a central amp. In addition to the cost, there is the issue of where to put the amp, and the associated issues of how to provide sufficient power to it; how/where to best run audio and speaker cabling; etc.
Although people have installed amps in the glove compartment (loss of storage space and heat issues) and in the trunk (more difficult and longer audio cable and speaker wire runs but close to power and ground connections), the easiest place is probably behind the drivers seat if you can stand to lose a bit of legroom. Behind the passenger seat might also be a location but the passenger legroom is already somewhat compromised because of the sub in the footwell. With the introduction of much smaller Class D amps, people have also suggested locating them under the seats but this space is extremely limited and I’m not aware of anyone actually doing this.
One of the benefits of locating the amp behind the drives seat is that it is not very difficult to run the amp power cable through a grommet in the firewall behind the driver’s left shoulder and into the engine compartment where it can be easily connected to the electrical block where you would also jump start the car. There are also a number of convenient locations to ground the amp on the inside of the firewall where most of the cars other electrical components are installed. This results in very short runs for both the power and ground connections as well as all of the amp audio connections which are easily run through the center console to the head unit and to the speakers.
Note that Science of Speed also sells wiring harnesses for both OEM and non-OEM applications which can simplify the wiring. This allows you to access the Left and Right channel line-out connections from the head unit and use them as line-in inputs to the new amp. The new amp speaker outputs can then be sent back to the wiring harness where they would travel over OEM wiring to the doors. However, because these are speaker-level, not line-level, you have to open up the door enclosures, bypass the BOSE amps, and connect directly to the speakers which is relatively easy to do. Alternatively, you can just replace the existing speakers with newer better ones. SOS sells replacement mounting kits which can be substituted for the OEM enclosures.
Re-working the sub can be a similar process. You could keep the existing BOSE amp/sub combo but most people will want to have the new amp drive it as well. Although the sub is small, it generates decent base if driven by a good amp try it before spending money on a replacement. You can always replace it easily later if you use the new amp to drive it now. In order to do so, you will need an amp with more than just the 2 channels for the doors but you can easily find 4 and 5 channel models where the extra channel(s) can be bridged or directly drive a sub. Ideally, they will also allow the option to internally bridge the L/R inputs to the extra amps but that’s not difficult to do if they don’t. As with the door enclosures, you’ll need to bypass the BOSE amp.
One issue with this approach is that, as was mentioned earlier, the OEM wiring to the doors is limited in it’s power handling capabilities so don’t try to put a gazillion watts through them. Also, if you do use the existing BOSE speakers, remember that they are very low impedence so turn the amp volume WAY down before testing them otherwise you may be replacing them soon. I also used the OEM sub but instead of using the factory wiring, I ran heavier speaker cable to the amp in case I choose to replace the sub in the future.
3. Replace the head unit with a double DIN one with video/GPS/etc and integrated amp
If you choose to go this way, the electronics piece may be simpler if the new head unit contains an integrated amplifier function. You’ll have the problem of where to get adequate power but you won’t have worry about where to put it and the cable runs will be much shorter. However, you will still need to bypass the BOSE amps in the doors and at the sub and have some of the same issues as in #2. The other more significant issue is in getting an acceptable double DIN replacement for the center console and getting the installation to look good and not have a lot of glare. Also, have a close look at the existing console design which narrows as it goes back so something you think may work on the face of the console may not have enough clearance for the deeper part of the unit.
Other Considerations
This is the first version of this thread and doesn’t yet include some other issues people may have with the existing OEM sound system such as:
• Options to connect various phones/players
Here's the 'condensed version' (but still huge thread) on iPod/iPad adapters: http://www.nsxprime.com/forum/showt...for-your-oem-NSX-Stereo-the-condensed-version
Here's one for Android: http://www.nsxprime.com/forum/showthread.php/164577-Android-Phone-to-OEM-Stereo
Here's one for Bluetooth: http://www.nsxprime.com/forum/showt...uetooth-audio-gadget-for-those-with-mp3-jacks
Here's one for AUX input: http://www.nsxprime.com/forum/showthread.php/142287-AUX-Input-for-OEM-Acura-Bose-Radio
• Ability to add equalizer and/or crossovers
• Sub upgrade options
• Other sound system issues such as:
o Display orange tint/brightness issues
o Antenna issues
o Loose/worn head unit knobs
• Soundproofing - try this thread on Dynamat: http://www.nsxprime.com/forum/showthread.php/151989-please-share-dynamat-door-install-pics
• OEM head unit connectors
Here's probably the original "Double Din" thread - lots of pages: http://www.nsxprime.com/forum/showthread.php/64651-Double-DIN-video-head-unit-thread
Builds/Inspiration:
1. http://www.nsxprime.com/forum/showthread.php/161234-check-out-this-center-dash
2. http://www.nsxprime.com/forum/showthread.php/161990-Pioneer-in-dash-double-dins
3. http://www.nsxprime.com/forum/showt...tion-amp-Double-Din-Modification-Lots-of-pics!
Center Console Replacement Options (not exhaustive - just some links I've squirrelled away):
1. http://www.nsxprime.com/forum/showthread.php/173522-Carbon-Fiber-Center-Console
2. http://www.nsxprime.com/forum/showthread.php/177941-Just-a-tease-Full-carbon-console-double-din
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