The sound system in the Honda s600 and s800 was not really great. Afterall most enthusiats preferred listening to the engines. So how to put in a decent sound and still keep an OEM look?
The Honda s600 had a radio available only as an option. Most of the cars sported a "blank out" plate with Honda written on it. So what are the choices in audio and can you reatain that OEM look and still have the functionality of a modern sound system?
Lets begin reviwing the OEM choices, the most popular is the blanking plate, that was originally produced in metal, and later in plastic. If you stick with the blanking plate, the audio system could be installed but would have to be completely hidden, and you have some choices from Custom Audio Sound, who make not only vintage looking units, but also RF remote control completely hidden units that could be mounted in the boot.
Here the blank out plate and the earliest Ten Audio radio which had a single button that was used to seek the station, this was the "Ten Audio" SS model (on right)
The basic radio optiion offered in Canada and Australia was the "Ten Audio" radio manufactured by Kobe Kogyu Corporation, model ST-34-1. This had an automatic tuning feature, the buttons on the top would activate a motor that would "seek" the channels up or down.
After the two versions of the basic AM radio and then an AM FM version FT-205-2 was introduced into the late Honda s600 and continued into the s800
A very rare and unusual option was the "Picnic Radio" which was a dash mounted radio that could be removed to take on a picnic. When a small release button on the front side was pushed, the handle would swing down and the radio could be slid out of the holder and was now portable. In picnic mode it was powered by batteries. and had an external antena and built in speaker! The flip handle was used to carry the radio so the other hand was freed up to carry the bento box to the picnic!
The Honda speaker was also very basic, It was a metal enclosure that would hang under the dash in the passenger foot well. Equipped with a single speaker, and protected from dust by a cloth bag. The enclosure had a ripple finish paint on it. A mounting bracket on the rear and the front.
From the parts book the radio and speaker mounting on a RHD machine, it is eseentially a mirror image on the LHD machines.
And here courtesy of the German S club, the mounting brackets for the LHD radio installation
So how to put in a modern system and maintain an OEM look? Essentially the OEM Honda s600 speaker is lousy, the OEM radio is rare and seldom is found in working order, and even when you can find one, it is very difficult and in most cases impossible to repair. Marc has introduced me to another alternative, Bill the Classic Car Radio Doctor, he will convert a classic radio to a modern one and keep the look. So if you are planning an audio system, why not keep the OEM look. Stick with the blanking plate or leave the Ten Audio radio in the dash for that OEM look and install a modern hidden system using a RF remote? The plus of the RF remote is that it does not have to point at the signal receiver, it just has to be in proximity. So you could even mount the remote faceplate in the armrest ashtray? I think that can work! The other feature is the added security. Yes you have a high end audio system in an open roadster, but it is essentially hidden from view and far more secure than putting something tempting in the dash.
A converted OEM unit in the dash, the blanking plate, or go with the OEM dash and a hidden unit with the RF controls in the arm rest, it is more of a financial question than a question of posibility.
The next issue is where to put the speakers. There is not a lot of room in the Honda s600 and the OEM speaker mounting box does not even accomodate stereo sound.
Some inspiration can be found with other roadsters, particulalry the Mazda Miata. Mazda with the 1990 to 1997 Miata model produced headrests to accept the installation of speakers. Apprently all of the seats had the spot for the speakers, and all may have had the factory wiring harness installed, but the headrest speakers were available only on the upgraded interior package. In Mazda and Datsun circles these seats are coveted, for both comfort and the design of the audio system. The speakers have become a very popular and easily obtainable aftermarket addition. Clearwater Audio offers a pair of upgraded speakers for both the drivers and passenger headrests for the Miata as a set for about $120. The original Mazda speakers were a square speaker, but the CA aftermarket are a higher quality speaker and the compact 3.5" (10cm) speakers are easily fitted onto the original Mazda fasteners in the headrest.
Inspiration has arrived! Looking at the OEM Honda headrests, there seems to be enough room to install a set of CA aftermarket speakers into them. In this case, I was going to reproduce a set of headrests in red for Aliquippa anyway, and now will include the mounting brackets for the Clearwater Miata speakers on the manufactured metal backing plate. The Miata uses a perforated plastic grill to cover the speakers, then a thin layer of foam over them, and placing perforations in the vinyl covering. Yes this will not be Honda OEM, but since I am reproducing the headrests and reupholstering the seat, it is a great opportunity to slip in a little modern convenience. I will keep the Ten Audio picnic radio unit in the dash and use a hidden radio and disc changer in the boot, to keep the original look.
A set of speakers in each of the reproduction headrests will provide some sound quality. The headrest picture on the right with a mockup of the 3" Clearwater Audio Speakers. Some 1/4" wire loom will connect the wiring in the headrest to the plug I will build into the seats, the wire can be run through the stiffener channel at the back of the seat frames, out the bottom and back into the boot. Maybe not for the purist, but the disruption in OEM look will be minimal. Importantly, the speakers are easily available and can be replaced. I may even hide a zipper in the cover to allow access for replacement.
Mounting a second set of speakers under the dash, or as suggested by Don on the S board, on the rear wheel wells behnd the seat, rather than cutting up the door panel; Both spots will be tricky because of the space constraints and to maintain the OEM look. But if the bulky speaker box can fit, a modern set of compact speakers should also be able to be wedged in under the dash or behind the seats. At least for the headrests I have a plan to go forward with. The rest I will investigate later. I will update this article as progress is made, time to order the Clearwater Audio speakers!
This week I spoke to Jeff who is a sound engineer, He has suggested that I put two small ports in the rear of the headrest in order to increase the Bass response. Apparently if the speaker cannot move enough air, the base response is not strong, and the mid and high end response is muffled and weaker; if the speaker is fighting a vacuum behind it and up agaist pressure in front of it, the sound gets muffled. He also mentioned that there are "flat" speakers that although the sound quality is not as good as a premium cone spreaker, for car installation they may suffice.
The original Honda headrest is crudely built. It is basically a welded support with a sheet metal backed headrest, and the assembly is stabilized by a wingnut in the middle and two pins in tracks at each side. None of this is particularly sophisticated or is it very stable.
The weight of two sepaekrs will also reduce the stability of the headrest in the support. I am leaning towards basing the "reproduction" head rest on aircraft grade 1/2 inch plywood. Aircraft grade or Marine grade is more expensinve, but has fewer flaws in the plys and has better glues for the potential outdoor exposure. Rather than go the single wingnut in the center of a metal plate, two Amico knobs and the ply would allow me to put in speaker ports in the back of the headrest, and more easily fashion the speaker mounts (than working in metal)
The ply backing will be covered in vinyl to match the headrest color. The Amico knobs as an alternative have a less industrial finish, keep the period feel, but allow the headrests to be adjustable and increase the stability. The knobs could also be finished to the color of the headrest with vinyl paint.
The look of the original headrest will come from the resulting frame that surrounded the metal back. This frame also stabilized the metal plate. The pin in the center is where the wingnut stabilized the headrest to the support frame.
The metal shop will make up the headrest frame to work with the aircraft grade plywood and also make up the attachment assembly to look OEM. Instead of the single wingnut, a pair of Amico knobs will be the attachement and adjustment for the headrest
With sound range for the high end response sorted, I beleive through the Clearwater Audio headrest speakers, I wanted to test some options to get a decent mid and low range sound response. I came across an idea that I will evaluate, and that is the Piezo flat speaker technology. Interestingly enough, Piezo flat speakers have been critizied for their lack of high frequency response, but do well in the mid and bottom range. The product I chose to evaluate is from Steiner & Martins, and is a true flat panel speaker. Claimed to be moisture resistant, rugged casing, humidity resistant, and work accross a broad temperature range, at 20cm by 30cm and 1.5 cm thick, finding a spot to mount these would not be an issue, even in the cramped space of a Honda s600 cockpit. Under the dash, on the transmission tunnel, wheel well, velcro to the side wall, the possibilities are endless. After I evaluate for sound quality I can decide where and if they can fit into the sound system. Either a cloth casing, or even vinyl, these would fade into the backgroud and still maintain an OEM look. By the way they come in at about $25 for the pair. Find them at Piezo speaker SMSPK3020800
Today the plastic sheeting and knobs arrived. The US Plastics poly sheet looks like it fits the bill well. I ordered two types, just to get an idea on the hole spacing, and will definitely proceed with the one with higher porosity. I am trying to paint the Amico knobs with a vinyl paint. I am not sure if I should give them a fine sanding to increase adhesion, or go with them native. The vinyl paint is really different from enamel, so I will try with sanding and without and then do a scratch test.
On the Yahoo sGroup list there was a lot of discussion around the sound response and it there is circuitry to increase the sound as the motor revs highly. These are great ideas, and as I get to the actual heart of the sound system I will evaluate them.
Continuation 12 29 2012
During Christmas the Clearwater Audion Speakers arrived, and the piezo flat speakers arrived. Good news and bad news. The Clearwater Audio speakers are exactly what I was looking for. Excellent quality. The Piezo speakers are not what I was hoping they are 20 mm by 30 mm and not larger as I had expected. I went back to the website thinking I must have made a mistake, but the units of measure were not as clear as they could be. I will still evaluate them further. Interesting, but really small.
I also got the seat frames back from metal restoration, and they will work very well for the wiring running in the stiffening channel. I will start the headrest backplate and speaker housings.