Speaker amps or head unit bad?

[chado]

Well I believe my speaker amps might have finally gone bad..cracking, then pop, then silence. Ive been in communication with BrianK and will be sending them this week for repair, however I have one question.
How can I be sure its not the head unit as no sound will play at all after the crack/pop? I would have thought a single bad speaker amp would only cause distortion from the single speaker.. That just my non-electrical intuition though. Anybody? Is there a way to test the head unit itself as well? It does still power on.

 

[NSX2398]

Based on my observations on Prime over the last 13 years, the probability that it is the head unit is very low compared to it being the amps. There's really no easy way to be sure in advance. Since there's an amp in each door and one for the sub, the poor mans approach would be to use the L/R control to see if one of the two door amps is more functional than the other .. or crank on the bass and see if the sub has any output. If this doesn't help with the diagnosis, then it gets tougher and more expensive.

The next 'easiest' way I can think of would be to buy the SOS factory head unit to aftermarket amp adapter cable for $30 (http://www.scienceofspeed.com/produ...d/ProFormance_Audiophile/stereo_wire_harness/) then dismantle the console to the point where you could unplug the factory harness from the head unit and then plug the SOS one in. Then use the RCA connectors on the SOS harness to feed the pre-amp signals to your favorite input device (RCA L/R to phone plug might be needed) and see if you get good quality audio. If you don't, then it's most likely the head unit. If you do, then it's the amps.
Removing the console isn't as difficult as it might seem .. but I can't seem to find the Wiki link at the moment.

 

[JLCoolman]

When I first got my NSX, it was having stereo issues. After looking on Prime, first thought was the amps had gone bad. I took them out (and interestingly enough, all three amps came from different year cars; can't remember if one was even from my model year) and sent them to BrianK for repair. Got them back and was still having issues. So I diagnosed by swapping left and right speaker assemblies that there was a problem with the head unit's output. Picked up a used head unit from another member. Finally got around to swapping it out a year later and things were better. But lo and behold there were different issues with the newer head unit or it was starting to act like the old one. My issues have ranged from poor output on a left channel when in CD mode but decent output on the left channel and no output on the right channel when in Radio/Cassette mode to other types of sound distortion.

So I've had two head units start to slowly go bad on me.
And I think we're at a point where the cars are just that old and head units are starting to have more issues than when it was mostly amp issues. Especially considering the head unit is something that is normally used quite often/day-in and day-out.

Just wanted to add my input.

As far as diagnosing, if possible try swapping the speaker enclosures, but then again if you have no sound at all then it's either all three amps went bad at the same time/close enough or the head unit is going bad.

Good luck.

 

[Rally Monkey]

There is a relay that converts the 5 volt head unit speaker output to 12 volt speaker/amp input. The symptoms are that the speakers will cut out intermittently especially on high volume. Two shops, AER Technologies in Brea, CA and Video Comtech in Anaheim, CA, first diagnosed the problem as the head unit's volume control being bad so it was replaced, but the problem persisted. Next, each shop bench tested the door speaker/amps and finally the footwall speaker/amp but they were fine. AER gave up and refunded my money. Finally, the second shop tested the in car wiring and diagnosed the voltage problem, i.e. the relay. The new part was only $16 from Acura and once installed the radio/stereo worked liked new. Save yourself time and money and replace the relay before tearing your car apart to remove and test the components. If it is not the relay, you are only out $16. By the way, if you have to remove the components, there are separate You Tube videos showing how to remove the head unit, door speaker/amps, and the footwell speaker/amp.

 

[N-Wing]

You need BrianK. He fixes anything to do with the radio or climate control for very reasonable rates.