Step 1 - Seat Removal

Step 2, seat removal continued

Step 3 - Open the Headrest

Step 3 - continued

Step 4 - Remove the Foam Speaker Cover

Step 5 - Headrest Rear

Step 5 - continued

Step 6 - Installation Detail

Step 7 - Fishing the Wire

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Step 7 - continued

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Step 8 - Install the Speaker Box

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Step 8 - Continued

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Step 9 - Wiring the Seat

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Step 10 - Install a Connector at the Seat Bottom

If you are installing our NABX1 headrest speaker boxes, you'll need to remove the seats. Put the top down and starting with the driver's seat, slide the seat all the way back and remove the two bolts with a 14mm socket and extension. Note that these will probably be very tight.

If you're just replacing the old factory HR speakers, you won't need to remove the seat. Just put down the top to give yourself room to work and jump ahead to the 3rd picture.

Slide the seat all the way forward and tilt it forward to get at the bolts in the rear. Remove these and the seat will be free. Before lifting, unplug the seatbelt buzzer wiring - it should be located near the seatbelt latch. If your Miata once had headrest speakers you'll need to unplug that cable, too (toward the front of the seat). Once everything is disconnected, carefully lift the seat up and out of the car.

The headrests on the Miata seats are accessible via a zipper. Pull back the cloth on the right side as you face the seat and using a needle nose plier, grab the tab of the zipper, raise it slightly to unlock it, then unzip normally still holding the zipper with the needle nose pliers.

Keep unzipping!

Depending on your Miata, this may or may not be screwed into place with two screws top and bottom in the center area. On the 1990 in the pictures, there were no screws - the cover was just sitting there. If you don't have screws holding this piece on, don't worry as it's held snuggly in place anyway once the seat is zipped up.

Take a look at the back of the headrest. Note the two small holes indicated in the picture. These are important as they are where your wires will exit.

If you're installing the Retrofit Kit, the front of the seat should look like this. If a previous owner has hacked away some of the foam or there are other speakers mounted, don't worry. Just remove the old speakers. If you are using our NABX1 headrest boxes, the appropriate screws are included to mount the boxes properly.

If you're just replacing the factory speakers, you can now unscrew them. If they don't fall out when the screws are removed, heat and time may have stuck them in place. Gently pry the speakers from the corners until they pop out. Pull off the speaker wires from each speaker. Note the wire teminals are different sizes for plus and minus so you can't mix them up. Our Millennium-5 speakers use the same arrangement so just push the wires onto the new speakers, screw them into place (careful!), and close up the seat in reverse order and you're done.

The pictures shows a closeup of one of the box mounting cavities. Note the red arrows indicating the screw locations - one at the top center and two at each lower corner. If the car has never had headrest speaker boxes installed before, the holes will likely be covered over with a very fine layer of foam. You can simply scratch that back with the tip of a screwdriver. Note the location in the lower center - this is where your wires will run through the seat to the rear.

From the front of the seat, take your hanger that has been opened and straightened, and insert the end into the location referenced in the previous slide and gently work it toward the back. Place one hand on the back opening shown earlier and insert the hanger at a slightly downward angle. Keep gently probing until you poke the hanger out the hole in the rear.

Once you have the hanger out the back, take your speaker wire (about a 6' piece is plenty) and tape it to the end of the hanger with electrical tape. Start the tape above the wire and keep wrapping downward so that you snug the speaker wire against the hanger. A couple of inches should do it.

When properly wrapped, it should look something like this. You don't want to use too much tape or it will be hard to fit through the seat foam.

Now stand to the seat side with one hand on the hanger and one on the wire. Gently and slowly pull the hanger back through the front and push the wire along with your left hand at the same time. You may need to wiggle the wire and rotate a bit to help pull it through the foam as there will be some resistance. If you pull the hanger off the tape accidentally, just repeat the procedure.

Success! Leave a couple of inches of wire to work with and then repeat the process on the other side of the headrest.

Take one NABX1 speaker box (there is no difference between 'left' and 'right' as the boxes are identical) and feed the wires through the bottom mounting hole. Now wiggle the box into place pulling back slightly on the foam as needed.

Take three of the 1/2" machine screws provided and fasten the box into place. NOTE: The screws mount into threaded plates built into the headrest. If your one or more of your screw mounts has been damaged by a previous owner, rust, or something else, don't worry. Just place the boxes into the foam at the appropriate location and fasten any of the screws you can. Once the headrest is reassembled and the cover zipped up, the entire assembly is held together so tightly that the boxes will stay in place, but in a car where inertia comes into play, we think it's always a good idea to fasten things into place.

Both boxes in! Now determine how you will attach the wires to the speakers. I prefer to solder wires whenever possible as they can't vibrate off and the connection can't corrode. If you're not comfortable with soldering, you can use some crimp-on spade connectors available at Radio Shack. Whatever method you choose, this is where you wire the speakers into place - watch polarity! The M5's have different sized terminals just like the originals. The temrinals are marked on the phenolic but you have to look closely to see it. The small 1/8" terminal is negative. This is also where you should install the special acoustic polyfill we supply with the retrofit kit. The polyfill just sits loosely in each box.

At this point, the back of the seat headrest should look something like this.

Screw in the speakers with the provided 1/4" pan head screws. NOTE: Use extreme caution! One slip of that screwdriver and you'll poke a hole right through your nice new speaker and ruin it!

If a Miata hasn't previously had wired headrests, we recommend that you run the wires through the center console tunnel and out through the carpet back behind the seatbelt area. You should also attach a connector so that you can easily remove the seats as required. Take your trusty hanger an gently work it up from the lower seat back right along the upholstery material. Be gentle!

Made it! Now mark one of the speaker wires on the exposed end to identify it as left or right. Then tape them to the hanger as before with electrical tape.

Note the markings on the wire to help you keep track of which wire goes to which speaker. Now gently pull the hanger out and draw the wires downward.

To facilitate removing the seat, install a 4-wire connector on the end of the speaker wires. For this install we simply used one we had available, but any 4-wire connector would be fine. See the note in the Materials section referencing a suitable Radio Shack part.

With the connector in place, you can close up the headrest area and set the seat aside and move on to the next seat. Reinstall the seat in the reverse order of removal. If you have some light oil available, put a drop onto each seat bolt before reinstalling. This will make it easier to remove them in the future.