1989-1993 JBL Sub Woofer Rebuild

1989-1993 Thunderbirds and Cougars equipped with Premium Sound Systems had 4 speakers 2 amps and a Sub Woofer. Blown Sub Woofer speaker happens to about every OEM system. The coil fails or the cone detaches from the foam either one requires the speaker be repaced. Ford does not offer a replacement sub speaker. This How-To will show how to replace the factory sub speaker with an aftermarket unit. Removal and installation of the sub from the car is not covered here. JL Audio makes a 75 watt 6" subwoofer speaker part 6W0 which is what we are going to use to replace the factory speaker in our sub. Full speaker specs are HERE.

Once the sub is removed from the car remove the bracket that holds the amp to the sub. Then remove the rest of the screws holding the sub together. Carefully pry the two apart. Break the sealing bead along the two halfs using a few flat blade screw drivers. or simular. The point to this is not to pull up one any one side too much or you will break the posts inside the box which the screws use to hold the box together.

After the two halfs are apart remove the screws holding the speaker to the box.

Once the speaker is removed there is a plastic retaining ring which is needed off the speaker. Glued to the rim you will have to pry it off the cone.
Note: Do not pry too much and break the plastic retaining ring.

The JL speaker comes with a rubber retaining ring. Remove the rubber ring from the speaker.

The OEM plastic retaining ring will fit the JL speaker.

You will need to glue the plastic ring onto the new JL speaker. He we used 3m adheasive. Weather stripping adheasive will also work.

OEM ring installed on new JL speaker.

The speaker can now be reinstalled in the box.

Before you can put the two halfs back together you need to modify the speaker support inside the box.
We measured that removing 1/2" would allow for the extra depth needed by the JL speaker.

We pulled the OEM foam backing from the blown speaker and reinstalled it onto the new JL speaker.

Before putting the box back together we need to extend the OEM wiring. The black wire with white lines is the positive.

The factory glue needs to be cleaned off the edges before the two sides are brought back together.
We used weather striping adheasive to seal the two halves of the box.

Reassemble the box and hand tighten the screws.
Do not over torque the screws as they will strip the plastic threads out of the box.

The weather stripping used to prevent the box from vibrating against the rear deck maybe defoarmed.
Replacement weather stripping is available from any hardware store.

Reattach the sub bracket and amp to the bottom of the box.
Before mounting the sub back in the car attach the power and amp input and test.
Reinstall the black foam over the speaker.
Then reinstall the sub back in the car.

MN12 Performance Inc.