My 62K mile, garage kept '86 GT has the factory Performance Sound system. It all seemed to "work" but not well. The tape deck didn't play and the sub surround is likely in bad shape. The sub played with the stock stereo unit and it was audibly controlled by the slide on the overhead control. However, there was too much distortion to use it. I kept the slide slid to min and lowered the bass end of the equalizer. That kept the noise down.
I decided to swap my Monsoon stereo from my non-Performance Sound '87 Fiero. I got the Monsoon from ReplacementRadios.com and it came with the adaptors. I had no trouble hooking the stereo up to the GT's factory wiring since the connectors were the same as on my other car. It sounds fine from the front and rear speakers but the subwoofer is even worse now.
It caused a pulsing distortion to be played through the sub. Attempting to adjust the sub's slide didn't help. Setting it to min and adjusting the EQ didn't help. The only way to stop it was to either turn the whole stereo off or to unplug the subwoofer. I chose to disconnect the two-wire plug near the subwoofer enclosure.
From my search, I found that I need to swap some wires somewhere because the sub's amplifier isn't getting enough power now because of the internal differences between the two stereos. I found this thread. I would have added to it but it is archived.
Can someone explain the process more clearly? Pics are always appreciated, too!
Thanks,
------------------ Jonathan 62K mile '86 GT daily driver 23K mile '85 notchie - Still under construction https://www.fiero.nl/forum/Forum2/HTML/121056.html Power tends to corrupt, and absolute power corrupts absolutely - Lord Acton Those who hammer their guns into plows will plow for those who do not - Thomas Jefferson The tree of liberty must be refreshed from time to time, with the blood of patriots and tyrants - Thomas Jefferson
The performance sound option has its own amplifier as well as the sub box and speaker. The amplifier is located on the right side of the fuel tank tunnel under the carpet, located by where the passenger's left foot would be when sitting in the passenger seat. it could be the amp is damaged. The speaker for the sub is most likely toasted, you can check that first and then proceed to the amp if it doesn't solve the problem. Try just unplugging it and plugging in a full range speaker for a bit to see if the distortion stops. Rodney dickman has a good replacement for the stock sub.
Power for the amp is normally changed to switched 12v source on most aftermarket stereo installations.
[This message has been edited by The Aura (edited 01-14-2013).]
I believe you need to take the pink wire to the amp and splice it to the the yellow coming into the radio. if it is a gm factory monsoon it shouldn't need to be switched over however, I'd try the speaker and amp test 1st.
The problem with not enough power, if i recall correctly, has to do with aftermarket radios and how conversion harness would utilize the power antenna circuit to power the amp.
To test if the speaker is blown just plug a full range speaker into where the sub speaker is plugged in the box. It will let you know if your amp is fried.
I got the replacement radio setup on my Monsoon--you need to cut the blue wire from the connector side and splice into the red wire--that is how it sends low voltage to the amp--your sub cone surround is probably gone--same with dash speakers too--I found the pieces of mine when I swapped out my dash--
------------------ Pat Jones
[This message has been edited by 88FieroGT TTops (edited 01-14-2013).]
In newer GM radios the power antenna wire is a signal not a power line, it oscillates up and down. In the Fiero, since it's a power line it was used to power the sub.
So I need to cut the blue wire, strip some insulation from the end that leads to the car, strip some insulation from the red wire without cutting it and connect the blue wire like a "T" and solder it together?
yes, with the end that goes to the harness...not back into the radio
Thanks guys, for the confirmation and the pic with instructions. I have new speakers coming so I'll be doing this probably tomorrow. I'll post my components, cost, source, and my review of them.
Until then, EVERYONE gets a (+) from me! Thanks for the help and participation!
I got my wires cut and spliced. I also took my sub box out. I removed my sub speaker and found that the surround was completely gone.
I also started work on making a mounting ring for my new 5 1/4 sub speaker. After three of them made out of 3/4" MDF split from the pressure of putting screws in, I decided to go with hardwood.
I got the component speakers from Amazon. Polk Audio AA5252-A MM5251 5.25-Inch System Component System (Mobile Monitors). These might be a discontinued item. They had the smaller magnets and didn't require modification of the heater duct under the driver's side.
They sound really good. I think I have a sensitive ear but I don't know much of the audio terminology so I can't really describe their performance in a way that would be useful to an audiophile. Anyway, I think this price was a bargan and they were definately worth the money.
I used the Tang Band 5.25 subwoofer just like in the thread linked above. I used 1" oak to make the mounting ring and some thin foam rubber to stuff between the wood and the sides of the plastic box. I also made a ring out of it and used that between the speaker and wooden mounting ring. That eliminated the buzzing I had prior to adding it.
Let me say that this was not an easy mod. I'm glad someone did all the work that they did and recommended the speakers but they made it sound much easier than it was. This took me several days to get right and I'm not sure if I'll leave it alone or try to make it even better. It DOES sound really good though, so until then, I will enjoy it the way it is.
.... cut the blue wire and splice it into the red ... problem solved.
