Stereo Head Unit and Front Speaker Replacement Guide
Guide to replacing the head unit and front door speakers in a 944 four-speaker system, covering DIN fitting, antenna amplifier wiring, fader bypass, and speaker fitment constraints.
Head Units
Replacing the stereo head unit in a 944 is straightforward. Any standard DIN head unit will fit, with a few minor points to consider.
When removing the factory head unit, a mounting frame for the new unit will likely be required. New head units include this frame; if purchasing a used unit, confirm the frame is included.
If subwoofers are planned now or in the future, select a head unit with subwoofer-out or rear-speaker-out connections. A unit with a subwoofer volume control at the head unit is particularly useful because the entire sound balance can be adjusted from one location rather than having to access a remote amplifier.
All 944s with windshield antennas also use an antenna amplifier. The amplifier receives power from a lead at the head unit. Two red wires with white stripes exit the head unit into the wiring harness and emerge as a single black lead that ties into the antenna wire. When installing a new head unit, a power lead must be routed from the new unit to the black amplifier lead, or to the two red/white-striped wires feeding it.
On 1985.5 and newer 944s with four-speaker systems, a front-to-rear fader control is mounted on the center console. The head unit sends left and right channel signals to the fader; from there, individual leads run to each of the four speakers. With a two-channel head unit, connect to the fader inputs as the factory unit did. With a four-channel output, the fader can be bypassed by connecting directly to the speaker leads exiting the fader — this allows full use of the head unit's own fader controls. The factory fader switch can then be left in place or removed and blanked off.
Speakers
This section covers 944s with four-speaker systems (front and rear). The front and rear speakers are 4×6 Euro-cut; 4×6 American-cut speakers can also be used.
Front Speaker Fitment
Fitting aftermarket front speakers involves three constraints:
Mounting plate: American-cut speaker mounting plates are slightly wider than the door opening and may require the bottom of the door panel to be loosened or the plate to be trimmed slightly. A thin mounting plate is essential — a thick plate will prevent the factory grille from sitting flush.
Depth: The door window channel runs directly behind the door speaker. The factory speakers use a 1/4" spacer, allowing approximately 1-3/4" clearance. Deeper speakers require a thicker spacer, which in turn prevents the factory grilles from seating flush. Aftermarket 4×6 grilles are available but uncommon; note also that any grille protruding more than 1/2" from the door panel surface will contact the dash when the door is closed.
Frame width: On most aftermarket 4×6 speakers, the oval frame is slightly larger than the oval cutout in the door panel. The best approach is to trial-fit candidate speakers against an actual door opening before purchasing. Some owners report finding speakers that fit without modification. Enlarging the door opening slightly by tapping the lip inward is another approach.
944 Front and Rear Speaker Compatibility Table
| Speaker | Application | Comments |
|---|---|---|
| Eclipse | Front | Requires slight modification of door opening. Great sound. Factory grilles usable. |
| Rockford Fosgate HPC1246 | Rear | Too deep for front. Perfect fit in rear. Great sound. |
| Alpine SXE-4625S | Front / Rear | Good sound. Perfect fit front and rear. |
| Alpine SPS-460A 2-Way | Front | Great sound. Fits perfectly. Factory grilles usable. |
| Clarion SRC-4652 ProAudio | Front | Good fit. |
| Infinity Kappa 462CF | Front | Thick mounting plate prevents flush fit with door. |
| Kenwood KFC4675 | Front | Questionable fit. |
| Kenwood KFC4625C | Front | Slight gap between grille and door panel. |
| Nakamichi SP-100 | Front | Fits doors with factory grilles. |
| Radio Shack 4×6 Three-Way | Front | Fits with no modifications. |
| Pioneer TS-A4605 | Rear | No fitment comments recorded. |
| Pioneer TS-A4612 | Front | Fits, but sound quality no better than factory. |
| Pioneer TS-G4611 | Front | Fits, but factory grille does not sit flush. |
| Pioneer TS-4615 | Rear only | Magnet too deep for front; usable in rear. |
| Polk Audio DB4620 | Front | Minor plate modification needed for factory grille. Very good sound. |
| Polk Audio EX462A | Rear only | Magnet too deep for front; likely usable in rear. |
| Sony XS-4621 | Front | Opening must be modified due to frame width. Factory grilles do not sit flush. Good sound. |
Note: Speaker fitment data compiled from community experience and contributed to Rennlist by Menelaos Karamichalis.