MSSS1 Information

When I decided to alter the MSSS system in my car there was very little information floating around on how to do it. If you posted something on the Miata.net forum you usually got someone talking about the standard stock system and they just assumed that it was applicable to our systems. Since I've upgraded my system, numerous owners have contacted me with questions about our stereo systems and what is necessary to alter them. This is a feeble attempt to create a reference page and not have to write up new emails all the time. I make no guarantees about any of this. What has worked for me has also worked for many other people, but may not work for you. Modify at your own risk.

Head Unit
The MSSS is made by Pioneer and is a self-contained unit. There is no seperate amplifier for any part of the system and though it looks as though the unit consists of two parts, they cannot be run independently. I don't have actual specs on the headunit but it's safe to say that the power output is no more than 15 watts RMS to the door speakers. These units are known for skipping notoriously while using the CD player. There are instructions out there to help reduce the skipping, but they didn't work long term for me so I don't feel they are worth including here. The head unit has six channels of power to drive the two seat thumpers, two sets of headrest speakers, and door component speakers.

Speakers
All of the speakers and seat thumpers (aka bodysonic, aka bass shakers, aka transducers) are manufactured by Pioneer. They do not have high power handling characteristics as they were designed to run off the supplied head unit.

The door speakers are a 6.5S sized speaker, also known as 6 3/4" speakers. Most speakers that size will drop into the hole without any problem and only require that a new screw hole be drilled in the door frame to firmly hold your new speakers. Occasionally a speaker's magnet will be so large that it can interfere with the door hinges, but this is rare. Our Pioneer speakers do not come with any sort of a rainshield like the stock speakers do. I recommend using XTC foam speaker baffles with the backs cut out when installing new speakers.

The headrest speakers are 3.5" speakers and each headrest contains two of them mounted to a plastic baffle. These are NOT the same speakers used in standard Miata systems. They are definitely a cut above and I haven't heard of anyone saying that replacing them is a worthwhile endeavor. I would only suggest replacing them if your speakers are audibly damaged. Our headrest systems also do not suffer from the miswiring that the standard headrest systems suffer from.

The seat thumpers do not produce sound, rather they vibrate to mimic the feeling a subwoofer provides. Their power handling is rated at 10 watts max. The wiring for the seat thumpers is located in the smallest wiring harness on the back of the head unit. There are only four wires in that harness, a positive and negative for each thumper. I didn't care for the thumpers at all with the stock head unit. I felt you could easily tell that there was something in the seat and that the vibrations were not coming from an actual speaker. I think this was due to the lack of bass put out by the door speakers. After upgrading the door speakers and amping them I'm a big fan of the thumpers. Their integration is pretty seamless now.

How To Upgrade
IMO, the weakest part of our system is the head unit. It skips like mad and doesn't put out enough power to enjoy the stereo at freeway speeds. It's the first thing I had to replace. Aftermarket head units have four channels of power, but we need six channels to power all of our speakers and thumpers. That means you're going to have to add an amplifier if you want to run everything. When I first changed out the head unit I opted to not run the thumpers. Like I said earlier, they didn't do anything for me. You may find that you need to source brackets from a standard Miata stereo or from a generic Metra mounting kit in order to get your new head unit in. It varies.

Step 1 is to go out and get a wiring harness for the car. Metra and American International are a couple of the companies who make them. You can order one from Crutchfield, Etronics, or it should be available for about $15 at your local car audio shop and it is easily worth the money. Follow the instructions on the package and wire up the harness to your new stereo's harness, then plug it into the harness in your car that currently plugs directly into the back of the MSSS. This will run your door speakers and headrest speakers off of the new head unit and complete the other needed connections.

The door speakers can be replaced with components or a coaxial speaker. I opted for MB Quart components and put them in the factory locations using the stock tweeter grilles. See page 5 for detailed information about that project.

If you want to continue to run your thumpers then the best option is to get an appropriately powered amplifier for your door speakers, then run the headrests and thumpers from your head unit. It makes absolutely no sense to run either your headrests or thumpers from an amp. Any decent aftermarket head unit will have more than enough power for your headrests and thumpers. You can see an overview on page 5 of my full installation, but it's pretty straightforward after you've wired up your new head unit.

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