Aftermarket Stereo and Headrest Speakers
Install on a 1997 Eunos Roadster

by Phivos Hadjigeorgiou
Nicosia, CYPRUS


Ever since I bought my 1997 Eunos Roadster I have been “inventing” ways of getting to spend more hours in it, be they behind the wheel (negotiating tight corners up in the mountains) or working on improving an already wonderful car. My latest fix involved the replacement of the stereo unit, with a SANYO CD Player / Tuner FXD-775RDS (4´40 Watt) and the installation of headrest speakers. The stereo installation was pretty straightforward since it was a plug and play affair, thanks to the excellent instructions that came in the box. The stereo installation took less than 1½ hour, whilst the headrest speakers took almost 2½ hours for both seats. The total cost of the whole affair was around USD 315, which was spent as follows:


1´ CD player / tuner CYP 127- Around USD 212

4´10 cm TSG –1055 Pioneer 80Watt, 3-Way speakers CYP 52- Around USD 93

120cm Speaker Wire, Wire connectors & pliers, Electrical tape and Army Tape -USD 10


Items needed for stereo installation:


·        Radio removal clips (if these are unavailable, the flat end of a teaspoon will do- worked fine for me)



Items needed for headrest speakers installation:


Same items used above plus:


Note: You may want to refer to these photos provided by Mark Jones as an aid to installation.


Chapter I: Stereo Installation


My car was previously equipped with an aftermarket CD player of atrocious quality (the thing literally exploded –fire, billowing smoke and all – a couple of days ago when I switched it on, so it was about time I bought myself a new one. I chose the Sanyo 775 RDS CD receiver, which I got at a great price, and whose output was 4´40 Watt, which is quite decent (Mind you, I am not a fan of too loud music).


First step was to remove the negative terminal of the battery, just to prevent shorting anything. After putting the top down, I removed the shift knob (just unscrew by turning it anticlockwise) and took apart the center console by lifting the ashtray out of its place, unscrewing the screw underneath it, the two screws in the center console storage compartment and the two side screws on either side of the console. Once these were undone, I pulled the center console out of the way and disconnected the ashtray light and the power window switch and set the whole thing aside. Next came the removal of the dash center plate, which came off by just yanking it off after removing a single screw on the bottom left of the center plate. Beware not to pull too hard, otherwise you may damage the wire connector of the hazard lights and pop-up lights. Following disconnection of the hazard lights connector, and after yanking the old stereo out of the center plate, I proceeded with the installation of the factory stereo. I followed the instructions in the box for the installation, as the stereo manual provided excellent instructions as to which wire goes where and how the connections had to be made. The kit includes a wire harness as well, which in my case involved cutting and replacing the factory wire harness with that supplied in the box. When making the connections for the front speakers, I also connected two lengths of wire of about 70 cm each for the rear left and right speakers, in order to connect the headrest speakers afterwards. I ensured that I properly marked each wire as left (L) and right (R) with a length of appropriately marked paper adhesive tape so as to be able to connect the headrest speakers properly when finished. I ran these lengths of wire on the top of the shift turret, where they would be covered by the center console and in the future would not require tearing half the car apart to get to. After making all connections in the way indicated by the stereo manual, I proceeded to install the metallic “harness” into which the stereo locks on the center plate. Before inserting the metallic harness into the single DIN slot on the center plate, I adhered thin strips of adhesive foam to the rear side of the center plate, around the slot where the metallic harness would be installed. This has proven to eliminate creaking noises resulting from poor installation when driving over bumps in the road. After inserting the harness into the center plate, I carefully bent the little notches cut into the metallic harness, achieving a snug fit of the harness onto the center plate. While the stereo was still not inserted into the metallic harness, I taped a couple more lengths of adhesive tape on the interior of the metallic harness to eliminate further noise that might come from the stereo rattling in the harness when driving over bumps (this achieves a snug fit of the stereo in its harness. Next, I replaced the center plate (remember the hazard light connector) connected the wire harness and antenna to the stereo (after double checking all my connections) then slid the stereo into the DIN slot. Now that I was done with the stereo installation, I reconnected the negative battery terminal in order to test the operation of the CD player.


After switching the stereo on and off and confirming that all was working normally (check fader controls and left and right speaker controls) I switched the stereo off and removed the negative battery terminal to begin the installation of the headrest speakers. It is not necessary to disconnect the battery terminal after installation of the stereo, as in order to damage the stereo, you will have to switch it on and short any wires attached to it. But I chose to do it anyway, as a crowd of “eager to help people” gathered around at the sight of my gutted Eunos, and therefore I thought I’d disconnect it just in case someone obliged to turn the stereo on whilst I was doing wire cutting or something.


Chapter II: Headrest Speakers Installation


This part required lots of patience, as the wire harnesses supplied with the speakers I used were a bit of a bummer to install into the seats of my Eunos, the seats of which incidentally were not pre-wired at the factory. The most difficult section of the whole installation was to ensure that whilst the wire used to “thread” the wire harnesses in the seats was being inserted through the foam of the seat back, no holes were punched in the cloth and vinyl upholstery of the seats. I used two 10cm TSG –1055 Pioneer 80Watt, 3-Way speakers in each headrest. The reason I chose this particular model was the fact that they have a shielded tweeter cone at the top, which prevents the main cone from touching the front plastic headrest cover, thus distorting the sound from the speakers.


My first step was to remove both seats from the car. This was done by sliding both seats all the way back and then carefully unscrewing the two15mm bolts holding the seat in place. Then I slid the seats all the way forward, undid the two 15mm bolts in the back as well as the bolt on the side of the transmission tunnel, holding the seat rail in place. (It is best to use a hexagonal wrench, as the bolts are quite firm, and lots of torque is needed to undo them. A hexagonal wrench reduces the risk of stripping any or all of them.) After the bolts were removed, I slid the seat tracks closed in order to prevent them scratching anything when I lifted the seat out of the car, and disconnected the driver seat belt buzzer (don’t forget to do this, as you will most definitely rip the thing off when lifting the seat out of the car).


I laid an old carpet on the ground, then carefully lifted the driver seat out of the car and set it down on the carpet next to the car. I unzipped the headrest zipper and pulled the seat trim down to reveal the foam on both sides of the seat. Next, I removed the plastic cover of the headrest to reveal the factory-molded holes for the headrest speakers. I then took the skewer and adhered on its end, the loose end of one of the wire harnesses that came with the speakers with some paper adhesive tape. I pulled on it a bit to ensure it had adhered properly. Looking at the back of the seat, I noticed two small (2mm) holes on either side of the seat, approx. 1½ inch lower than the bottom of the molded headrest speaker hole

I then pushed the skewer into the foam on the right speaker hole at an angle aimed at the little hole in the back of the seat. It took a couple of tries, but eventually I managed to thread the skewer through the foam and out the back of the seat, through the small hole mentioned above.

Next I pulled the skewer out the back end of the seat, threading the wire through the foam, leaving about 2½ inches of wire (including the harness end connectors) on the other side. Looking further down the seat (about 7-8 inches from the top) I saw a larger hole in the back of the seat. With one hand, I inserted the skewer at an angle of 45° into the foam on the back of the seat, and pushed it in, aiming for the seat cushion towards the front middle of the seat.

At the same time, I pushed my other hand into the back of the seat cushion at the front of the seat and slowly pushed it as far up as I could reach, feeling for the tip of the skewer that I kept pushing through the back of the seat towards the front. When the tip of the skewer finally came through, I grabbed it and carefully pulled the skewer through the foam whilst being careful not to rip the seat cloth covering the seat cushion or the bolster (the process of pulling the skewer through is rather awkward; I had to bend the skewer into a curve so as to avoid piercing the seat cloth). I then carefully tucked the harness into the space between the seat back and the seat cushion, pushing the end of the wire through the seat back to the bottom of the seat.


I repeated the process for the left speaker as well, being careful not to pierce the cloth or vinyl back of the seat.



NOTE: If the wire harnesses do not come in different color (mine did) for left and right, please make sure you mark them appropriately so as to avoid making wrong connections.



The installation of the speakers is one step before last to be taken before re-closing the headrest of the seat. The units I used are 10cm TSG –1055 Pioneer 80Watt, 3-Way speakers, which came with four metal brackets on the circumference for mounting, which I had to cut off by twisting a few times back and forth. I then connected each speaker to the wire harness, ensuring that both terminal shrouds covered the terminal connections fully to avoid shorting the speaker. I then inserted the speakers into the speaker mounting holes in the headrests, after cutting a crescent-shaped slice of foam off the foam that separates the two speaker mounting holes (this ensures a better fit of the speakers into the seat back, as they do not bulge as much on the sides).

The process of finishing the installation involves a couple of “cosmetic” modifications to the installation in order to ensure that the wire harness does not show through the cloth or vinyl of the seat. Looking at the back of the seat, at the level of the headrest speaker holes, you will see two lengths of wire about 2 inches long (these are the loops of wire that hang over the foam of the seat back, as a result of the threading of the wire harness through the bottom of the headrest speaker mount hole to the back of the seat and then rethreading it through the seat foam all the way to the front of the seat. I figured that after closing the seats up, these wires would “show through” the vinyl of the seat back, so I took a blade knife and carved a 2mm deep slit along the path of both wires. I then pushed the wires into the slit in the foam, and taped the foam with some army tape. Although the foam of the seat is quite heavy, thereby eliminating the danger of it parting sometime in the future and creating gaps in the back of the seat, I taped the slits closed as well to add some extra rigidity to the foam where it was weakened due to the cutting.

At long last, I replaced the plastic shroud over the speakers and zipped the headrest closed. The fit this far was excellent, with the seat headrest becoming better defined (it is now about 1cm thicker than before. No disfiguring of the seat has occurred anywhere.



I then put the seat on the floor lying on its back and taped the wires of the headrest speakers to the middle of the floor pan being careful not to damage any of the steel wires used for moving the seat backwards and forward (also make sure it does not interfere with the wires at the bottom of the seat). Before replacing the seat into the car, I brought the seat as close as possible to the car, and fed the length of wire from the wire harness into the hole in the carpet, (underneath the seat) which I threaded under the carpet towards the transmission tunnel. (At this point a friend lifted the seat up and started putting it in place so as to enable me to thread the whole length of the wires properly). I took the ends of both wires and pulled them through the carpet out where the center console is installed, and connected them to the appropriate wire connectors coming from the stereo.



REMEMBER: EACH SEAT HAS A left and right speaker installed; do not get all confused and connect both seat speakers onto one wire, SINCE ALTHOUGH THEY WILL PLAY PERFECTLY OK, you will lose the stereo effect AS BOTH SPEAKERS WILL BE CONFIGURED AS RIGHT OR LEFT, NOT RIGHT AND LEFT.



I ensured that no excess wire was left so as when the seat is in place, there would be no looping out from underneath the seat. I then reconnected the seat belt buzzer switch and bolted the seat back onto the floorpan.


I repeated the same procedure for the left (passenger seat), ensuring all wires were connected properly. After finishing all connections, I put lots of electrical tape over the connectors for good insulation and reassembled the center console in reverse mode to the disassembly described above. Whilst assembling the center console, I took time to carefully tuck all wires away in a manner that would prevent them from rattling when driving over rough roads.


After the car was reassembled, I started the engine and went for a quick spin (well actually the whole testing trip ended 2 hours and 200km later) to test my new acquisition. As soon as I fired the stereo up, I was amazed at the quality of the sound I was getting; the front speakers, in combination with the newly installed headrest speakers gave an amazing response with the top both up and down, and at motorway speeds (over 130km/h) the music was still as clear as ever. The stereo needed to be cranked up a bit higher, as now I am running a total of 6 speakers on a stereo that gives an output of 40 Watt on 4 channels. Even so, with the volume turned on max, it is still unbearable to sit in the car, as the music is way too loud for anyone’s ears. Even better, the speakers´ maximum output capability of 80 Watt and nominal input of 20 Watt ensures that they will not rip or burn for a long time. I have done this installation almost a month ago, and I have had no problems just yet. Well, just about no problems…ever since I cannot get myself out of the car, much to the dismay of friends and relatives!


I hope that the information and diagrams I have provided will help other fellow Miata owners to install their own headrest speakers. Needless to say, I cannot accept responsibility for anyone cutting his hands or injuring himself, ruining his/her seats, stereo or entire car or inflicting any other damage to himself or any other person/property alive or dead.


Phivos Hadjigeorgiou

Nicosia, CYPRUS

Back to the Garage

22 February, 2003