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Version 0.1.9 (last updated Febuary 5, 2002)
Note: The following is a draft. Most of the following information has been gleaned from personal experience in my '86 944. Additional information on differing models, features, and installations would be most appreciated. Please send additions and corrections to wws@sgi.com.
In general, most 924s and almost all 944s were equipped from the factory with Blaupunkt electronics. The 968 had either Blaupunkt or Alpine electronics. The cars can be divided into the following categories:
The factory provided a location for a DIN-sized head unit in the center console. There is a center dash speaker location for use with mono radios. Cars delivered with stereo radios typically had a pair of speakers installed in the quarter panels on either side of the rear seat.
Morgan (ref 7) lists the following options available (few M codes - can anyone help clarify?):
Jan 1976:
June 1976:
Aug 1979 (924 Turbo):
Feb 1981:
Starting in 1983 all cars were delivered with 4 speakers: a 4x6 inch speaker in each door, and a 4x6 inch speaker in each rear quarter panel on either side of the rear seat. An external fader control was located in the console for front/rear balance.
1983:
85/2 944 onwards (4 speaker system)
There is space for a DIN-sized stereo with provisions for a small equalizer in the center console. As with the earlier cars, each door has a 4x6 inch speaker and there are a pair of 4x6 inch speakers in the rear quarters. An external fader control was provided for speaker balance in 85/2 and '86 models. From '87 on, 4-channel head units were used - so no external fader was needed.
The electronics and speakers were typically Blaupunkt. A typical U.S. 944 came with a Blaupunkt Monterey SQR 23 radio with cassette. The two front 4x6 inch speakers were Blaupunkt "whizzer cone" speakers and the rear speakers were 4x6 inch Blaupunkt coaxial speakers. An in-glass windshield active antenna replaced the fender-mounted antenna of prior years. This antenna system incorporates a Fuba preamplifier, located under the dash.
1985/2, 86:
1987:
1988:
1989:
1990:
1991:
In some post-'87 cars, the rear 4x6 inch speakers are mounted to an
adapter plate. Removal of this adapter plate allows a 6 1/2 inch
speaker to be mounted.
85/2 944 onwards (M490 10 speaker system, M493 8-speaker system)
This system consists of a better quality head unit with an equalizer/amplifier in dash. Each door contains 3 speakers - a 5-1/2 inch woofer and a 4 inch midrange mounted under the armrest with a small tweeter mounted above the power window controls. Each rear quarter contains 2 speakers - a 6 1/2 inch woofer and a ?? inch midrange.
1985/2, 1986:
1987:
1988:
1989:
1990:
1991:
The M493 option for the cabriolet was similar to the M490 option, but
with 8 speakers rather than 10.
The car came with a six-speaker sound system. Dashboard layout and speaker locations are similar to the 85/2 and later 944.
Morgan (ref 7) lists the following options and chronology:
1992:
1993:
1994:
The M490 amplifier option is really two 2-channel amplifiers, one under each seat.
AM/FM/Cassette - 2 audio channels:
AM/FM/Cassette - 4 audio channels:
AM/FM/CD - 4 audio channels:
(Note to readers: Please help me complete the above table and the following descriptions!)
Blaupunkt Monterey SQR-23 (U.S. 944 '85 to '86)
The Monterey is a digitally tuned AM/FM stereo radio with a built-in cassette player. (The AM section also supports the European 'long wave' band. However LW is not used for broadcasting in the Americas.) The cassette player supports Dolby B encoded tapes.
The two built-in power amplifiers in the Monterey are rated at 9-10 watts output (RMS) each - at unspecified distortion - into a 2 ohm load.
Repairing the pushbuttons (thanks to Al M. - who defected and bought a Miata.):
";The push buttons are made of a circle of metal suspended by a thin rubber doughnut. The rubber breaks and its all over for that button. I managed to remove the switch (careful not to lose the spring!) and replaced the rubber/metal piece with chewing gum wrapper (aluminum foil). I fixed all but one button this way. The last button popped out and I lost the spring."
Blaupunkt Lexington SQR-45 (U.S. 944 with M490 10 speaker option)
The Lexington is a digitally tuned AM/FM stereo with built-in cassette player. The cassette player supports Dolby B encoded tapes.
There are four power amplifiers, however only the front two are used. The speaker level outputs are connected to a graphic equalizer located below the head unit.
Blaupunkt Reno SQR-26 (U.S. 944 '87 to (at least) '89, M158)
The Reno is a digitally tuned AM/FM stereo with built-in cassette player. The cassette player supports Dolby B encoded tapes.
The two built-in power amplifiers are rated at ?? watts output.
Reno factoid: A lister reported that using his analog cellphone (both a Motorola and a Nokia), which was placed in the pocket under the Reno, would cause interference with the microprocessor. The sound would shift to one side. The radio would need to be reset, by pulling and reinserting both fuses.
Porsche CR-1 stereo
(How to key in the security code?)
Graphic equalizer/amplifier (M490, M493)
A graphic equalizer/amplifier is provided with the high-end 10-speaker systems. This is either a Blaupunkt BEA-80 or BEA-108 in a 944. The 968 has a different setup.
The BEA-80 is a 7 band equalizer with center frequencies at 60, 150, 350, 800, 2000, 4800, and 12000 hz. A front/rear balance control is also provided. The unit contains 4 output amplifiers, each rated at 15 watts continuous (0.7% distortion), and 20 watts peak (10% distortion) into 4 ohms.
The BEA-80 has both line-level inputs, via a ?-pin DIN plug, and speaker-level inputs via 2-pin DIN plugs. In '86 cars the speaker level inputs are used. Line-level interfacing is always preferable to speaker-level interfacing to avoid the distortion inherent in an extra (and unneeded) amplification stage.
The output jacks on the back of the unit are 2-pin DIN sockets.
(What are the pinouts on the BEA-80 low-level input DIN plug? And did post-'86 units use the low-level inputs instead of the speaker-level inputs?)
(What are the differences between a BEA-80 and BEA-108? )
In the 968 the external amplifiers are located under the front seats. Each is a two-channel unit. The wiring for them runs from the DIN connector on the back of the head unit, through the tunnel on the drivers side, then splits off to the individual amps.
Radio removal
Blaupunkt radios can be pulled from the dash with a pair of U-shaped wire tools that fit into the small holes in the corners of the unit. Though most any car audio store will have these tools, they can also be fashioned from a bit of coat hanger wire.
Power connectors
The wiring diagram in the Haynes 944 manual is nearly useless - especially for later cars. A better idea is to go to your dealer or a shop that has the factory service manuals and photocopy the pages for your exact car. The Mitchells manuals are also an excellent source of accurate schematics. Many public libraries have Mitchells manuals available for perusal.
Crutchfield may be able to provide adapter harnesses to avoid the need to cut up your wiring.
The six-pin connector commonly used in mid-80s has two large pins and four smaller ones:
(Anyone know of a 'reverse' connector for the Monterey-style plug?)
A second set of power connectors are provided for the optional equalizer/amplifier (85/2 and later):
Fader Control
A console-mounted front/rear fader control was provided with two-channel stereos. Cars from about '87 onward (and '85/2 and '86 with the optional equalizer/amplifier) have four-channels internally, so the extra fader control was not needed.
Nowadays, any quality aftermarket stereo has four internal channels, so the external fader control is not usually needed. Unplug the fader from the speaker wires, and then plug the new stereo straight into the speaker wires using 2-pin DIN sockets. If you want to remove the fader control, you can obtain a blank filler from Porsche (part number 944-613-256-00, about $3.00, for 85/2 and later cars.)
Speaker connectors
Porsche used 2-pin DIN plugs for the speaker wires. Most new stereos will only supply pigtails (wire with no connector) for connection to the speaker wires. To avoid cutting up the OEM plugs, buy a few DIN sockets and solder the pigtails to the sockets. Then just plug the new stereo straight into the wiring harness.
One source of 2-pin DIN plugs and sockets is Metra - who make a variety of car stereo interfacing products. The Metra 70-1693 contains a pair of 2-pin DIN sockets. If your new stereo has 4 audio channels, and you are bypassing the OEM fader control (or equalizer), you would need two of these Metra adapters. The Metra DIN sockets are stocked or can be ordered by most car stereo shops. Metra also sells a couple of styles of 2-pin DIN plugs. These are listed in their catalog for Mercedes and VW applications. Any car stereo shop should either stock, or be able to order Metra parts. (If they can't, you *really* need to find another stereo shop...)
A few other sources of 2-pin DIN plugs and sockets:
Unfortunately, Tandy/Radio Shack does not stock 2-pin DIN parts.
The schematic in the Haynes manual for speaker wires is incorrect for 85/2 and later cars. The color codes used for the various speakers are:
One problem with DIN connectors is that the largest recommended wire size is only 22 gauge. This spec ripples through into the factory wiring - which is probably also 22 gauge. So when using higher power head units and amplifiers, you may wish to consider simply abandoning the factory speaker wiring and simply running new ones.
Equalizer
The space below the stereo is used for an equalizer/booster in the M490 option. While it appears to be DIN sized, there are screws on the lower corners and inner clearance problems which may prevent a full-height DIN-sized equalizer from fitting. So a half-height equalizer with some sort of cover plate below (or around) it may be your best bet.
(What have others done?)
CD Changers
To my knowledge, the factory has never supplied external CD changers for the 924/944 series. So custom mounting will be necessary. The most common location to mount a changer is in one of the rear cargo cubbies. Some 6-CD changers are small enough that they can actually fit in the front glove compartment.
(The 968 did have a CD changer option. Was it mounted in the rear cubbies?)
Power Amplifiers
To my knowledge, the factory has never supplied external power amplifiers for the 924/944 series. So custom mounting will be necessary. The most common location to mount external amplifiers is in one of the rear cargo cubbies. Other possible locations include the spare tire well, under the passenger seat, under the floor board (next to the DME), and under the dash. Not much room in these latter locations...
On the 968 series, optional external power amplifiers were located under the front seats. One on each side. Each of these amplifiers was a 2-channel unit.
Fuse box access (85/2 944 on, 968)
Two fuses are used for the stereo:
Access to the underside of the fuse box:
Door Speakers (4 speaker systems)
The doors are usually provided with 4x6 inch oval cutouts with "European metric" style mounting. The factory 4x6 speakers are Blaupunkt full-range "whizzer-cone" speakers with a paper cone and foam surround. There is a rubber shield protecting the rear of the speaker from moisture. The paper cones on these speakers are very soft, so break up easily at high volumes. The foam surrounds provide very little excursion, which also contributes to poor sound at volume. The Xmax (maximum linear excursion) of these speakers must be very small. Also the foam surrounds become brittle with age and crack - further contributing to poor sound.
All cars, except the cabriolet, have a steel window track passing directly behind the door speaker area. This causes a serious restriction in available speaker depth. With the usual flat "waffle" style speaker grille (part number 477-867-081), this limits the depth available for replacement speakers to about 1-5/8 inches.
Cabriolet owners are lucky - the smaller window allows the full depth of the door for speakers! I have heard of custom installs where 6.5 inch speakers have been installed. This obviously requires some trimming of metal and upholstery by the installer.
A second, and nicer-looking, style of 4x6 mounting was used in some later ('88+) cars. This is a two-piece assembly consisting of a thick plastic frame and a snap-on grille. The grille area is made of metal with a plastic surround. The frame acts as a spacer, making it possible to mount speakers as deep as about 2 inches. For example, an Audax VE4X6F0 mid/woofer, which is 52 mm deep, barely fits. It actually presses against the window track.
The parts list for the later grille assembly is:
Note that the bushings are important to space the frame out far enough from the door panel to allow the grilles to snap on. Also note that the replacement speakers MUST be the European oval shape,- not rectangular. The replacement speakers must also have a thin steel mounting frame like the OEM speaker - not a thick plastic one.
The least expensive approach to mounting a deeper 4x6 inch speaker may be to make a simple spacer out of, say, 1/2 inch MDF and use the flat waffle grilles. Spacing the speaker much further out than this is not possible as part of the grille is covered by the dash when the door is closed. (924 and early 944 have more clearance than later 944 and 968.)
If you are installing coaxial speakers, also make sure the tweeter does not protrude too far. For example, certain Infinity speakers have this problem. The JBL GTO-462d does not.
Last, many people have replaced the oval 4x6 inch speakers with `4x6
'plates' or round coaxial speakers. All other things being equal, which
they aren't, a 4x6 woofer should be more efficient at producing bass
than a smaller round speaker. So if you do not plan to use a subwoofer,
you may wish to stay with the oval form factor.
Door Speakers (10 speaker systems)
The ten-speaker system includes three speakers in each door. Two of these speakers, a 5 1/4 inch woofer and a 3 1/2 inch midrange, are mounted under the armrest instead of the storage bin. A small tweeter (1 5/8 inch, 3/4 inch deep) is mounted high in the door - above the power window switches. These speakers are connected to a 3-way crossover network, which is also located in the door.
(How deep can replacements for the woofer and midrange speakers be?)
In 968s, the factory speakers were supplied by Nokia.
Front center speaker (924 and early 944 only)
In the early 1970s, when the 924 was first designed, monophonic (single channel) radios were still quite common. So a single speaker was all that was needed. In most cars this location is now unused, though it might be usefully employed for specialized radio needs (e.g., cell phone, amateur radio, scanner or CB radio external speaker).
A second possibility is to use this location to improve the sound
staging of a stereo system. In the book Ultimate Auto Sound (ref 2),
there are ideas for implementing a simple center channel concept. The
author even includes construction details for a simple center channel
mixer and bandpass filter.
Rear speakers (4 speaker systems)
The rear speakers are located next to the rear seats in the side panels. Once again, these are Blaupunkt 4x6 inch speakers. The units in my '86 944 were actually coaxial speakers - paper cones again but with a rubberized cloth surround and larger magnets than the front speakers. Despite the coaxial design, they are not very good sounding speakers. (What other factory 4x6 inch speakers have people found in there?)
According to the Crutchfield catalog, the depth is restricted to 2 inches. However this does not seem to be the case in the 944 and 968. At least 3 inches are available, allowing just about any aftermarket 4x6 to be used. Perhaps Crutchfield is thinking of the 924 - whose fenders do not bulge like the 944?
In '87 and later cars, the 4x6 inch speakers are mounted to an adapter plate. Removal of this adapter plate will allow a 6.5 inch round speaker to be mounted. Be sure to check for this before purchasing replacement 4x6 inch speakers. Here are a few photos that show what was found in an '87 924S (many thanks to Gary Coots for the photos):
Gary notes that the holes in the side panels do not exactly line up with the 6.5 inch speaker. He carefully lined out a grid of holes to match the spacing and pattern of the existing holes. Then used a Dremel tool to drill a few new holes in the panel. A felt tip marker was used to touch up the new holes, and a bit of cloth was glued behind the new holes. (Speaker grill cloth is available at Radio Shack, and probably any car stereo installer.)
Removing the side panels to get to the speakers is not difficult, but takes some time and especially care. Do not attempt it when you are tired or in a hurry. Here are the steps:
As noted in step 6, it is not required to remove the side window. However if you really, really want to, here are the instructions (from TurboTim):
To replace the side window:
Rear Speakers (M490 10 speaker systems)
There are two (Blaupunkt in the 944, Nokia in the 968) speakers in each the rear side. These are a 6.5 inch woofer and a small midrange. The grill is held onto the interior panel by nuts. The woofer is mounted to the body of the car, and the mid-range is mounted between the panel and the grill.
On a 968, plastic trim surrounds the window and can be snapped out during the process of removing the interior panels.
Subwoofers
The factory did not supply subwoofers so custom installs are necessary. Ideas which do not require cutting up the rear carpet:
Ideas which do require cutting up the rear carpet:
For several good and inexpensive ideas on subwoofer installations, see Ultimate Auto Sound (ref 2).
Antennas (924 and early 944)
The 924 and early 944 typically have antennas mounted in the driver side front fender. These are Hirschmann units and came in both manual and power versions. The Haynes manual (ref 4) has information on removal and replacement.
Starting with the 85/2 944, an in-glass windshield 'active' antenna system was used. Under the dash, between the glove box and the passenger side fender, there is a small black box containing a preamplifier - made by Fuba. This amplifier is powered by a lead which runs alongside the coax leading to the radio. It connects, through the wiring harness, to the 'power antenna' lead on the radio in order to get power whenever the radio is turned on.
On the 968 series, a small roof-mounted antenna was used. This is mounted just in front of the hatchback. It is also an 'active' Fuba-style antenna, and is wired in a similar manner to the in-glass version.
When installing an aftermarket radio on a car with an active antenna system, it seems to be a common problem to forget to apply power to the preamplifier. The following are the most common symptoms:
As noted before, the power lead for the preamp is a black wire which is run alongside the coax. The two share a common length of tubing between the preamp and the radio compartment. To find this wire from the radio compartment, just follow the coax into the dash a few inches and eventually you will find where the wires leave the tubing. The black power wire then connects into the wiring harness for the car. The lead reappears at the radio connector so that the radio can provide switched power.
A good web site with some interesting technical information on Fuba antennas is Antennaworld.
Antennas (Advanced Topics)
My 1986 944 came with both the in-glass antenna and a Monterey radio with long-wave (LW) reception. Although LW is not used for broadcasting in the U.S., there are low-power aircraft and marine beacons. So some people without a life actually try to see how many of these beacons they can pick up. It turns out that the factory setup is quite deaf to LW with the in-glass antenna. I actually once parked about 50 feet from a maritime beacon and could not receive it!
Amateur radio operators may wonder about good places to install 'ham' antennas. One solution to the problem is to use the pairs of ski-rack bolts, which are under the upper side of the hatchback. A mount can be fashioned from a bit of aluminum and is strong enough to support usable VHF/UHF (e.g., 144 and 440 MHz) antennas.
For amateur short-wave operation (and 11m CB radios), I've wondered how a magmount on the rear bumper would work. Using some copper shielding material to make a GOOD ground connection to the chassis would be important for efficient operation! An article in the December 1997 issue of QST (Ref 6) has some ideas for making effective use of a magmount at these frequencies.
Note that the sunroofs are non-metallic - so a magmount won't work on it.
Last, what if one wants to receive shortwave or longwave radio from the car, such as when using a car stereo like a Becker Mexico or similar Philips (and certain gray-market Sony) stereos? If you have a 924 or early 944 you have it made. Just use the stock antenna. However the later 944s with the in-glass Fuba antennas are more problematic. The in-glass antenna system seems fairly deaf to shortwave signals - especially the high bands. The 49m band seems ok. Attaching a small whip to a hatchback-side mount seems to work. One list member has successfully used the roof-mount active antenna from a 928 (part number 928-645-201-00) with the older and now-infamous Philips DC-777 radio. This roof antenna is also a Fuba-style unit. (Is this the same part as used in late 968s?)
Blaupunkt does stock some parts for, and repair, old radios. In many cases it may be less expensive to simply replace the unit with a more modern design. However it is always nice to see well maintained examples of original equipment in older cars. (Just ask any 356 fan!)
In the U.S., Midwest Electronics seems to be Blaupunkt's official repair and parts center.
AM radio reception is especially sensitive to a variety of noises around the car. Three common areas of noise are:
Raspy noise - check plug wires. Many list members use Magnecor plug wires, which are designed to both maintain peak engine performance and minimize electrical interference. Magnecor has an optional CN25 version of their wires, which are especially designed for suppression at radio frequencies. (See Magnecor's web site for more information than you ever wanted to know about plug wires. Some cool pictures of racing engines too!) Make sure the rotor/cap are in good condition. Make sure that good 'resistor' spark plugs are in use.
Other areas to check for raspy noises include faulty fuel injectors, and improper bonding of the antenna or engine to the chassis. Of course if you have replaced your metal hood and fenders with carbon fiber parts, do not blame Porsche for poor shielding!
A high-pitched whine, which varies by engine speed - this problem is almost always caused by the alternator. Alternator problems seem rare on our cars. Individual repair parts are available; so total replacement of the alternator is not required.
A second cause of whining problems could be caused by 'ground loops' from external power amplifiers, CD changers, and the like. It is important to have a good common ground connection between all the units.
Clicks - caused by windshield wipers, turn signals, etc. If these are bothersome, try replacing the associated relay.
Auto Audio (ref 5) has a nice chart for tracking down and solving noise problems.
Goal: Replace the old Monterey with something modern, replace the aging 4x6 speakers. All existing wiring will be maintained - NO connectors will be cut off or modifications to the cars wiring harness.
Parts list:
Steps:
1.) Pull the Blau. Examine the power connector, follow speaker wires to the fader control, find the DIN connectors running to the individual speakers.
2.) Build out the wiring harness for the new stereo. Use the Metra sockets for the speakers. This will allow a simple 'plug in' installation. If you cannot find a 'reverse' connector for the power plug, you might try soldering spades which match the connector. (Then use a lot of electrical tape to make sure it is secure.) Or again using spades, but with the idea of using unused equalizer power wires.
3. If you have an 85/2 or later car, make sure the 'power antenna' connection is correct so that the Fuba preamp works properly.
4. Since this is a 4-channel radio we will be bypassing the fader control. Unplug the speaker wires from it and plug them into the new Metra DIN sockets in the new wiring harness.
5. Plug power in and test. Verify that the channels are hooked up correctly by fading front to rear and right to left.
6. Insert head unit into the dash opening.
7. Front speakers are easy - 4 screws each. Just make sure the new speakers are shallow enough to fit.
8. Rear speakers are harder - see directions above.
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