Dash Speakers: All model Fieros used the same dash speakers, 10 Ohm 4" x 10" Delco units. As far as we can determine, the vehicles below used the same speakers somewhere in the vehicle. Note that Fieros which had "Premium Sound" (sub woofer option) had different speakers than other Fieros. A minimal amount of data on the "premium sound" speakers is shown below. ("Premium Sound" is the option which includes a separate amplifier and subwoofer system.)
Buick Skyhawk '85-89 Cadillac Eldorado '84-85 Chevy Blazer '88-94 Chevy Cavalier '85-94 Chevy Cavalier RS '86-90 Chevy Cavalier Z24 '85-87 Chevy Citation II '85 Chevy El Camino '85-88 Chevy Monte Carlo '78-88 Chevy Pickup EL '85-88 Chevy Pickup S10 '86-95 Chevy Suburban '92-95 Chevy Suburban '92-95 GM Caballero '85-88 GM Jimmy '88 GM Sonoma '93-95 GM Yukon '92-94 GMC Pickup '91-95 GMC Pickup Cab '85 GMC Pickup S15 '86-93 Olds 98 '84 Olds Custom Cruiser '90 Olds Cutlass '84-88 Olds Regal '78-87 Olds Riviera '84-85 Pontiac Bonneville '85-86 Pontiac Grand Prix '86-87 Pontiac Sunbird '84-88 Saab 900 '86-93
The original Fiero speakers are 10 ohm impedance. For optimum life on the factory radio/amplifier you should use 10 ohm replacements. Use of 8 ohm speakers or worse, 4 ohm speakers, will cause the amplifier to run hotter for the equivalent sound level as a 10 ohm speaker. If you do not run your radio/stereo at full volume, use of speakers which are not 10 ohm impedance should not make much difference.
We have read that the '98 and newer Chevy Tahoe and Chevy Suburban have 4 x 10 rear speakers which will transfer easily to the Fiero and work well. We do not have personal experience with this swap.
A same-size inexpensive replacement for the dash speaker is available under the brand name "Linear Research", Stock Number LR410S. This is a Chinese-made speaker which is advertised as 75 Watts nominal, dual cone, for 4-8 Ohm systems. This has been used successfully even though the OEM speakers are 10 Ohm impedance. We suggest the Linear Research speakers are not a good choice with high-power amplifiers but they do work with standard Fiero radio/tape players and would be a reasonable choice when repairing a car for purposes of sale. We have seen these speakers available at Pep Boys for around $15. The distributor is Recoton Company, 1090 Emma Oaks Trail, Lake Mary, FL 32746, (800) 732-6866.
There are many good quality aftermarket speakers such as Kenwood KFC-451C, Pioneer TSA-4103/4105 and AutoBahn AS41Q at about $100 a pair. The "Eclipse" brand is also reputed to be a good choice as are the Polk MOMO line, although the Polk units were discontinued in 2007 and may only be found on places like eBay. The Pyle PLG41.3 4"x10" Triaxial Speaker Pair is reportedly a very good replacement at around $33/pair plus shipping. Speakers are available at most audio shops and via the Internet at sites such as crutchfield.com and cardiscountstereos.com. Some speakers will come with plugs requiring an adapter or will need the wiring soldered or mechanically spliced. See the heading "Speaker Connections" below in this regard.
If you have the "premium sound option", the speakers are two-way units and provide better sound quality than the conventional OEM speaker. As of April 2005, replacement two-way dash speakers are available from GM Parts Direct for $27.44 each; the part number is 16042082. Unfortunately we do not have the part number for the companion sail panel speakers.
If a new speaker is desired, JL Audio makes one but we don't have the part number. Radio Shack makes a 5.25" Woofer (#40-1032) for about $20. Its wattage is 30 RMS, 60 peak, effective range 80-8,000 Hz, but we do not know the impedance and it may not be a good match for the amplifier. You will need to use some spacing material at the four mounting screws if this speaker is used. Sub woofer speakers can also be obtained at rodneydickman.com for about $35-40.
Speaker Connections: If you are working on speakers, note that the terminals labeled "A" and "B" on Delco speakers are - and +, respectively.
When using aftermarket speakers you may want adapters to connect the new speakers without resorting to cutting, splicing, or soldering. If so, you will need plug-in adapters to match the new speaker connections with the Fiero connector. In December of 2008 the following adapters were found using a web search. We have not verified these personally and you should check carefully to make sure they match both the old connector and new speakers:
From Circuitcity.com, Item number MET DW4500SH, $12.99/pair From Crutchfield.com, Item number 12071009, $9.99/pair From GDIElectronics.com, Metra part number 724500, $4.62/pair
Custom Installation, Soundproofing: An excellent writeup on upgrading the sound system in a Fiero is located at this link:
http://www.fiero.nl/forum/Forum3/HTML/000031.html