I've installed an updated system in my 84 project car (OK - it's an Indy).
I wanted a stock look and much better sound without building an all-out system like I have in my 87 GT.

One of the first things to do is gut the interior and install soundproofing of some type.
This will quiet the car from road noise and greatly improve the acoustics and efficiency of your stereo system.
There's various products around like Dynamat and it's competitors and some people also use peel 'n stick roofing materials with success.
Don't forget to cover the back of your door panels.





I'm using Infinity component speakers in the front dash and Clearwater Audio Headrest Speaker sets in the seat headrests.
The in-dash 2000+ Pontiac Monsoon CD player will power all the speakers.
For the subwoofer, I'll be using a very small Xtant 1.1i 100 watt mono amp to drive a subwoofer in a stock Fiero sub-housing.
I'm using the TANG BAND W5-1138SM 5-1/4" Neodymium Subwoofer from Parts Express in the housing.


FRONT DASH SPEAKERS
I wanted a high quality component set in the dash and chose the Infinity 50.7CS component set.
The woofers have the compact high efficiency neodymium magnets with heat sinks.
The Infinity set comes with passive crossovers (2 wires in, 4 wires out), 2 to the woofer, 2 to the tweeter.
With the set's very high 94db efficiency rating, it works very well with factory deck power.


http://www.infinitysystems....ountry=US&Region=USA
This is how the Infinity components fit into the 4"x10" dash opening.
5.25" woofer and 1" tweeter on a speaker plate made from 3/16" hardboard.





I've done up a template that can be used to cut out dash plates. The hardboard can be pretty fragile,
especially around the 5.25" cutout, so alternative materials such as 1/4" ABS plastic would be better.



This file is in MS Word format and will print in proper scale on regular letter sized paper.
There's a Bar Scale in the left corner. If it matches up to a ruler, it has printed properly.
DOWNLOAD the file from here: http://www.fierosound.com/speaker%20plate.doc


HEADREST SPEAKERS
Many have replaced their stock headrest speakers with aftermarket 4ohm speakers.
Looking at the Fiero manual wiring diagram, the headrest speakers are clearly wired in parallel.
This will create a very low 2ohm load using 4ohm aftermarket speakers
(stock were 10ohm creating a safe 5ohm load) and could eventually damage your factory deck's amplifier.

I replaced the seat?s headrest speakers in my 84 project car with a set of
Clearwater Audio Miata headrest speakers. http://www.clearwateraudio.com/product.html

Clearwater Audio now has a Fiero headrest speaker set (they can be bought on eBay as well).
They created a new part number CWC-3F (F for Fiero) and added the correct connectors so it's just a plug and play installation (once you get the seat apart).
They are 3-1/2" 2-way speakers with the correct power rating for a stock deck (10-25 watts) and 7-8 ohms each.
These will work with the stock wiring with no changes other than an inline bass cap (optional) and it won't overload the amplifier.

When your order the Clearwater Audio headrest speakers, here's what you can expect.

What you get in the box - 4 high quality speakers, well packed.



The speakers already have a pigtail with the correct connector to plug into the existing harness in the seat.



The connector makes installing the speaker a simple "plug 'n play". I checked, and the polarity is correct.



Here's how the Clearwater Audio speakers compare to the stock Delco headrest speakers.



Here they are pressed into the foam of the headrests. It works, but GM could have found a better way to install these.



For anyone who's never had their seats apart, here's how to do it. http://www.mrmikes.com/fierospeakers.htm


SUBWOOFER SYSTEM http://www.fiero.nl/forum/Forum3/HTML/000079.html

The Fiero Store sub-housing just bolts into the Fiero since it's a factory duplicate.
If you have an 86 or newer, your heater box should already have the correct support bracket that supports the Convenience Center
(chime box, flasher etc) as well as the sub-housing. I had a Dickman sub at first, but saw this thread and decided to try the Parts Express
sub as mentioned by Bigfieroman. http://www.fiero.nl/forum/A...090219-2-076432.html

BIG improvement, especially since I am running 100 watts vs the stock amp's 20-25 watts.

This picture shows how the Fiero subwoofer box is mounted. I was using it without the tube and with a Dickman sub at the time, but later changed that.
Because the tube is tuned for the stock speaker, it needs to be modified to match the new speaker's specs. Cut off 2 inches from the end.
The housing is slightly undersize, so loosely stuff it and the tube with poly fiberfill (cheap at Walmart) to make it work better. This is how the stock subbox sits behind the dash.



I purchased the TANG BAND W5-1138SM 5-1/4" Neodymium Subwoofer from Parts Express
http://www.partsexpress.com...?&Partnumber=264-831

Here's a comparison of the Rodney's replacement sub to the larger Tang Band subwoofer



Don't let the small magent fool you. It's a Neodymium magnet - more efficient, more powerful and can therefore be smaller but producing
the same power as the large regular iron core magnets. Not sure why more manufacturers aren't using the Neodymium magnets.
Probably because the BIG magnets are not only cheaper, but more impressive looking to the unknowing buyer who thinks "bigger is better"???



I made a mounting ring from 3/4" MFD. The edges were coated with silicone (to seal)
before slipping it in and attaching it through the sides with screws. Pre-drill the holes or the MDF will split.



The subwoofer attaches to the front. The stock grill will no longer fit, so I used the mounting ring and grill from the
Infinity speaker (sanded and painted Satin Black) to protect the subwoofer.





Not my car - found this video on YouTube - recorded with a cell phone I think.
Unfortunately, a YouTube video doesn't give you the "in the car" sound and feel.




DECK, ADAPTERS AND SUBWOOFER AMPLIFIER
A 2000+ Pontiac Monsoon CD player replaces the stock radio/cassette unit.
I'll be using an Xtant 1.1i 100 watt mono amp to drive a subwoofer in the stock housing.
The Xtant amp is 6.5" x 5.7" x 1.6" high which will fit under the passenger seat out of the way.
This tiny amp really delivers and is perfect for the job.
Amp specs http://www.xtant.com/archiv...oducts/xtant1.1i.cfm



Comparison of the amp size to the deck.



I purchased a Delco radio adapter harness (simplifies A LOT) to connect the new Delco to the Fiero?s wiring harness.
I made all my new connections in this harness so as not to modify any of the car?s wiring.
The NE-7V adaptor taps the signals from the front speaker wires and provides 2 RCA level outputs (left/right) that will run the subwoofer.
These will connect to the adjustable PFMOD LP-1 Low Pass crossover (set to 133Hz) which sends a mono signal to the Xtant subwoofer amp which then powers the subwoofer.
I also soldered the bass caps for the headrest speakers in the adaptor harness as well.

Amp with Low Pass filter and line output adapter wired to the radio adapter harness



NE-7V adapter http://www.davidnavone.com/adaptor_products.htm
PFMOD LP-1 crossover http://store.hlabs.com/pk4/...e.pl?view_product=26



I have the thing working - the sound quality of the Delco radio tuner could be better.! I was starting to think this whole setup was a waste until I played some CDs and connected my MP3 player. I ripped my MP3s at 256Kbps which is pretty close to original CD quality (320Kbps is better yet, but the files get REALLY big). Awesome sound playing CDs and MP3s through the system. Not as great as the setup in my GT, but still impressive for something that looks all stock. The MP3 is connected with a Peripheral Integrated Electronics (P.I.E.) GM9-AUX auxiliary input interface. This allows connection of any MP3 player through the CD Changer Aux. port on the back of the Delco player. There is also an iPod specific interface available from P.I.E. http://www.peripheralelectronics.com



I was experimenting with the settings on the PFMOD LP-1 Low Pass Crossover for the subwoofer. I tried it at 89Hz but found that 133Hz worked better, allowing the sub to produce more midbass. I had installed Bass Blockers (capacitors) inline to all the speakers to cut the lower frequencies.

When you have a subwoofer in your system, you usually want to decrease the amount of bass going to your mid-range speakers (tweeter will already be crossed-over). This will give your speakers better mid-range and high end sound and increase their power handling while reducing distortion by rolling off the bass before it gets to your mid-range speakers.

To do this, you use a "bass blocker" (high pass filter), a capacitor placed in series with the speaker input. It blocks the lower frequencies, and allows the higher frequencies to pass through. Bass blockers are installed in series, one end connected with the positive lead from your amplifier and the other end connected to the positive lead of each of your speakers. Bass blocker capacitors are available at any Radio Shack, eBay, Crutchfield etc. or parts supply house. You could also use an electronic crossover to filter the signal, but using capacitors keeps it simple.



I used capacitors inline before the 2-way crossovers to the front speakers which block frequencies below 50Hz. At present this seems to be a good crossover point for the Infinity component set with the subwoofer. For the headrest speakers, I used caps which block frequencies below 100Hz. I installed these inline behind the radio in the adapter harness rather than at the harness connecting to the seats.

Use 50-100 Volt Capacitors - Values for 2/4/8 ohm speakers.
Polarized or non-polarized will work, but be sure to install polarized capacitors in right direction.




HOW DOES ALL THIS SOUND?
Since my subwoofer setup gets its signal off the front channels, switching the fader completely to REAR headrest speakers only, eliminates the front speakers and all subwoofer output, so there is no mid-bass or bass at all. Playing the headrest speakers only, with a cutoff at 120Hz (with the bass blockers) you are only playing midrange and higher. The speakers reproduce this very clearly and can produce quite a bit of volume without distortion. BUT, you?d never be listening to the system with this setting except for testing purposes.

By nudging the fader toward the front very slightly, I got the subwoofer to come in and a very low volume from the front speakers. In fact I had to lean up to the dash to hear them at all. At this setting I was basically listening to the headrest speakers and bass/mid-bass from the subwoofer. This immediately "fills out" the sound immeasurably - and oddly enough, it "sounds" like the mid-bass is coming from the headrest speakers!

With the fader set "dead center" I found that the front/rear balance is exactly correct when sitting normally. I listened to all kinds of music for almost an hour, including Big Band, drum solos, country, heavy metal, and rock and roll. The front sound stage is full, wide and complete without the ?center hole? of the stock system. At first you think the headrest speakers aren't working at all, but as soon as your turn your head slightly, you'll hear that headrest speaker right away. While looking straight ahead (as you normally would), the overall ?concert hall? effect is excellent.

I would recommend both the Infinity component set and the Clearwater Audio headrest speakers. The Parts Express subwoofer is a big improvement over a stock subwoofer, and I would recommend this easy upgrade for people wanting more bass without building trunk or firewall subs. The newer Delco CD decks fit and look great and will connect and play MP3s with the appropriate adapters, which makes large bulky CD Changers pretty much obsolete.

Bottom line ? I'm VERY happy with the results, and that's saying a lot, because I'm comparing it to my "other system" in my 87 GT. Total cost for everything was about $1100 - but it sounds like MUCH more.


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My World of Wheels Winners (Click on links below)

3.4L Supercharged 87 GT and Super Duty 4 Indy #163

[This message has been edited by fierosound (edited 08-09-2020).]

quote Originally posted by F-I-E-R-O: I can't tell you how much I appreciate your posting this! A + for you and a stick in the eye of who ever gave you a neg- I see a sliver of red... on the other hand, without it you'd probably just be a robot.

Thanks. I've posted all this information in different threads before. I just pulled everything together into one place so it's easier to get a sense of the whole system.

[This message has been edited by fierosound (edited 04-05-2007).]

[This message has been edited by fierosound (edited 04-11-2007).]

Great right-up Soundman, good info

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