Stereo Modifications

Soon after purchasing the car I recognized that the system wasn't up to much, the PO had fitted a Sony Mobile ES CD player (which was about all he had done to the car) and there was volume but no bass. In my opinion the head unit looked out of place in the dash too. Put up with this for a while and then began investigating as I got more confident.

Found the factory amp and there were a bunch of wires that didn't belong, the connectors for the front and rear speakers had been removed from the amp and wired directly to the stereo with the two 6" woofers still being driven from the amp. I rewired the amplifier back in, this proved somewhat difficult as the stereo shop had discarded the connectors that plugged into the amp, the sound was much improved with more bass but with the head unit wound all the way up the volume was not that impressive. Sounded like a mismatch between pre-amp output of the Sony and the Blaupunkt Amp, even though the Sony had a 4V pre-amp output that should have over driven the amp if anything.

After reading about several peoples success with using the latest and greatest Blaupunkts I phoned Stefan Weiss (1-800-270-2378) and purchased the Blaupunkt Toronto with an adapter so the unit would just plug straight into the factory harness. I knew that my harness had been hacked but the standard connector was still behind the dash hanging on by a singular wire !!!! I also ordered some connectors from Stefan that would enable me to correctly hook up the speaker wires to the amplifier..

While the new stereo was on-route I took the Sony out and began re-wiring the old connector back in, it soon became obvious that the harness had been hacked twice during its life, a whole spiders web of wires was removed. I soldered the the wires back on to the old connector and used heat shrink to cover up the joints.

New stereo arrives and was up and running in minutes, wow what a difference, sound was much improved and the unit looked at home in the dash, especially at night with the orange display.

Stereo.jpg (50125 bytes)Blaupunkt Toronto amp.jpg (71051 bytes)Amp rewired with new connectors AmpInternals.jpg (48620 bytes)Inside the amp

Never one to quit fiddling I decided the speakers were up for modification next. The Pioneer GS1040's fit snugly in the door panels and don't require spacers which would have made an uneven look beside the tweeter. Wal-Mart sells these speakers for a very reasonable price. Carving up the standard speaker gave me the necessary bracket to fit the original grill. Tin snips were used to trim the pioneer speaker to ensure everything was hidden behind the grill.

Speaker1.jpg (53038 bytes)Speaker2.jpg (61480 bytes)

Next up were the rear quarter speakers, trouble is the standard speakers are very shallow (1.5") and there is not an aftermarket item that will fit in the recess without a spacer. I originally purchased some Infinity Reference speakers but it wasn't possible to get the standard grill to fit over the tweeter, so again ended up with the same Pioneer times that I used in the front.

Manufacturing the spacers was a little overkill but it was fun so what the heck ...., bought a chunk of 5" aluminum bar and with the help of workmate Alan Mimms (he has a lathe and mill in his basement) machined the solid bar to produce the spacers below. Spacers were then sprayed black and placed in the car.

 me.jpg (40888 bytes)Me doing the technical stuff ... Spacers.jpg (30197 bytes)Machine finish look

(Need to add photos off speakers in car with spacers sprayed matt black, very stealth)

While messing around with these rear speakers I was surprised by the lack of volume coming from these 4" speakers (both after market and standard items) especially when compared to the front. I took a look at the crossover fitted to the back of the woofer and found the circuit shown below. This indicated that the speakers were wired 'backwards' with the high pass filter going to the 4" and the low pass going to the tweeter. Swapping the green and yellow wires improved things again. I only have the schematics for the 8-speaker setup so am unable to determine whether this was a factory error.

Shorting out the 6R6 resistor also puts more power to the rear 4" which helps balance the front/rear volume.

RearCrossover.jpg (12201 bytes) Rear Crossover Circuit (factory configuration)

FrontCrossover.jpg (7392 bytes) Front Crossover Circuit

Next up were the 6" speakers, there is not much depth here and it is very necessary to save the plastic molding around the speaker as it is contoured to ensure a 'custom' fit. First job was to remove the crossover and then cut out the paper cone, I hack sawed off the magnet and then hack sawed the small ridge on the face so the new speaker would sit flush.

Now is the point when you think, hmmmm, wonder if this was a good idea .......

Last job with the hacksaw is to remove the plastic support where the negative speaker terminal resided, this will allow the new speaker connectors to be accessible. Then refit the crossover and solder on some speaker connectors.

I found some Kenwood speakers (KFC-167X) which are pretty similar in dimensions to the old ones, they do come with an integral tweeter which is unfortunate as the outputs on the amp have a low pass filter limiting frequency response to about 3KHz. Oh well they look good .....

Sounds good so far but the standard grills won't quite fit as the new speaker sits about an 1/8" too high, rather than modify the molding further I removed the mesh form the standard grill and sat the new speaker on top. Now I can use the Kenwood grill but if I decide to change back to the standard grill later all the bits are there.

6_1.jpg (35932 bytes) Here is the old speaker and a modified molding
6_2.jpg (37787 bytes) This is looking at the back with the new speaker inserted
6_3.jpg (33770 bytes) Comparison of new and old (without grills)

Here is the finished item inside the vehicle.

6_4.jpg (19394 bytes)

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