e9stibi

Disclaimer: This procedure has been written to my best knowledge. I do not take any responsibility for any damage to goods or persons that result from usage of this procedure. Be always careful when working on electrical systems and apply the precautions listed in the component manuals. (e.g. disconnect ground terminal at battery and secure it).

There are a lot of good write-ups about installing aftermarket hifi components in a Porsche 993. As part of my planning, I spent about 1 day to review all the postings for information and learnings both on Rennlist and the German PFF forum. In addition I did some measurements for an Amp placement under the seat.

I would like to share my experience in a comprehensive summary. I suggest that some of you guys add critical points or missing information and we make this a DIY procedure.

I will post in 2 parts because my project has two stages:

• Part 1: Replacing Nokia amplifier (hifi optioned car) and installing two passive crossovers for a 6.5” Woofer that will be positioned in the front doors as part of a 3 component system
• Part 2: Replacing Nokia 3 component system (hifi optioned car) in the front with after market 3 component system

This will be part 1. Part 2 will follow later when I have finished the project.

Required Tools:
• Tool to pull Porsche radio (ebay)
• Good basic toolset with screw drivers, wrenches and pliers
• Good hex-key for seat bolts
• Dremel to slot or cut off seat bolts if stripped (based on experience there is a good chance for this happening)
• Chisel and hammer to get out the stripped seat bolt
• Basic electrical tools (cable cutter, electrical tape, soldering iron)
• Fluke to measure cables and plugs for proper connectivity
• Jig saw to cut plywood
• Drill

Installation environment:

• 1996 Cabriolet with Hifi-option and DSP from factory (Nokia Amp under passenger seat, driving 3 component system in the doors and 2 coax speakers in the rear)
• Porsche CDR220 with Aux input for external audio source.
• Rear Nokia coax speaker replaced with 4” Helix DB 4.1 Dark Blue (Art-Nr.: H015041). Perfect fit with no cutting after you remove the rubber around the magnet.

Main Upgrade Objectives:
• Place aftermarket amplifier under the passenger seat with 2 Channel Amp
• Drive rear speakers from head unit
• Must be capable of being transferred to stock again
o No cutting of main harnesses or plugs
o Keep the old equipment
• Replace front door speakers with 3 component system
• Keep stock look
• Budget for main components: 600 USD max

Measurements and Options for Amplifier: (see picture 1 below)

My objective for placing the amp under the seat limits the selection for aftermarket solutions. I spent half a day on research. The listed options will not be exclusive but they are a starting point.

I went with the Soundstream Stealth STL2.560 (170 USD on ebay):
• Class A,B (not D! Amazing for this size)
• 150W x 2 at 4 Ohm and 14.4 V
• H: 53mm / 2.1", W: 166mm / 6.5”, L: 285 / 11.2”
• Connections at front and back (and not sides) which is beneficial due to limitations of control units at the sides

I do not know if the other options work but you can judge based on the Soundstream STL2.560.

Options for a 3 component system:

I wanted to have:

• Tweeter that fits factory housing
• 4” (10cm) Mid speaker (like OEM)
• 6.5” (16 cm) Bass speaker (OEM 5.25”)

I considered Focal, Dynaudio and MB Quart. I found a test in a German Hifi magazine that compared the three systems. Dynaudio won the test but did not fit my budget. The Focal came in second were still too pricey. However, I had Focal 2-componet speakers before in my Audi TT and really liked them. I ended up with the MB Quart system that I got for 200 USD online. This is the last series that is still hand-built in Germany (and not China) but it is discontinued. You need to be fast to grab the remaining sets.

This is what I bought:
• MB Quart RVF 210 (130 USD)
o 2 component system with tweeter, 4” mid and passive crossover
• MB Quart RVF 164 (70 USD)
o 6.5 “ woofers to be added via passive crossover

Installation of Amplifier

• Remove passenger seat (for more details see p-car.com “How to change to a performance tuned CHIP”)
o Be careful not to strip the bolts. The OEM bolts are soft as butter. I replaced the factory bolts with better quality from Sears.
o Unplug the connectors for electrical seat adjustment and optional heating
o Protect the open door area with a blanket. The seats are heavy and bulky and you do not want to hit the body.
• Unplug and remove the Nokia amp
• See picture 2 how it looks with Nokia amp still installed
• Place the new amp at the location (no cable connections), fix it to the bottom plate and put back the seat to test if it interferes with the amp.
o I did not bolt the seats for this test but moved them back and forth while observing the gap between amp and seat
o For my Soundstream amp there was no interference at all.
• Remove the seat and unscrew the amp to continue with cable routing and connections.

Cable Routing

Objective was to use existing cable if feasible and not to cut any plugs.

There are 3 main plugs that I needed to achieve this:

1. Radio plug for speaker output (Plug B) to connect the rear speakers (had one extra). -> see picture 3 for details

2. DIN 8 pin female plug (270 degree, solder type) to build an adaptor from the grey DIN plug to RCA plugs for amp signal input. -> see picture 4 for details how the pinnumber relate to pin location

1 N/C
2 Red – Front left
3 Green – Front right
4 Black - Common
5 Yellow – Rear right
6 White – Rear left
7 N/C
8 ??? Most like 12V switched (did not use and measure because I ran extra cable)

3. Nokia plug for the speaker output wires, positive, mass, amp switch etc. I cut this plug out of a donor amp that I got from a rennlister. If you cut the plug, connections will be much simpler because you can solder directly to the cables

Pin# Wire color Function

5 Brown Power GND
6 Brown Power GND
10 Red Power +12V
11 Red Power +12V
13 White/Red Speedo signal

7 Shielded Blue/Black Gnd for DSP controller
8 Shielded Blue/Red Data for DSP controller
9 Shielded Blue/Yellow Clock for DSP controller

16 Brown/Green Front Left Woofer -
17 Green Front Left Woofer +
24 Brown/White Front Left Mid/Tweeter -
25 White Front Left Mid/Tweeter +

19 Brown/Yellow Rear Left -
18 Yellow Rear Left +

20 Red Rear Right +
21 Brown/Red Rear Right -

23 Black Front Right Mid/Tweeter +
22 Brown/Black Front Right Mid/Tweeter -
15 Violet Front Right Woofer +
14 Brown/Violet Front Right Woofer –

The pin numbers are taken from the Service Manual wiring diagram for the 95/2 model (sheet 9).

There are several ways to run the cables. Here is what I did:

1. Rear speakers to radio speaker out (Plug B)

I ran the speaker cables under the middle tunnel and routed them to the Nokia plug (pin# 18/19/20/21). You need to go under the carpet for the transition from middle tunnel to seat mounting area. There is a good DYI on P-car.com on how to remove the middle console. (“How to change your hand brake lever to Techequipment hand brake lever”)

2. Amp switch input to radio amp switch output

Used the same route as for the rear speakers.

3. Ground connection for amp

I ran 2 cables to prevent ground noise. One cable from the radio ground to the amp ground input (same routing as above) and one big ground cable from a ground point in the seating area to the amp ground input

4. 12V connection for amp

I took advantage of my learnings from the rear foglight installation described at p-car.com (“How to install rear foglights”). Just use this guidance to get the cable from the right side of the passenger compartment into the trunk area under the fuse and relay box and from there it is straight forward to the battery. To rout the cable to the amp I removed the carpet at the right side (see the foglight procedure for running the cable to the rear foglight)

5. Front speakers to amp speaker output

As I said before, the MB Quart system came with two big passive crossovers for each channel. I placed the crossovers for the woofer under the driver seat because I think the doors cannot house 2 crossovers effectively. Another advantage is that the factory harness already had 2 pairs of speaker wires for each side (Woofer, Mid/Tweeter) because the Nokia amp acted as an active crossover for the factory woofer. More about the placement of the crossovers in the next chapter. Here is the cabling:

- amp speaker out to crossover input under the seat: over the tunnel (under the carpet)
- crossover output (woofer) to the factory plug (pin# 14/15 and 16/17): over the tunnel
- crossover output (mid/tweeter) to factory plug (pin# 22/23 and 24/25): over the tunnel

The area over tunnel got crowded with the cables but if you put them neatly next to each other, they will fit under the carpet without being bulky.

Installation of crossovers under driver seat
The crossovers are fairly flat and there is enough area to mount them under the driver seat. I mounted the crossover on a piece of plywood and screwed the plywood to the sheet metal under the seat.

See picture 5 of the installation below:

Finalize installation of amp and crossover

• Use cable binders to secure the installation of all cables.
• Reinstall radio temporarily (don’t push in before final testing)
• Test the system. The advantage of this phased approach is that I can use the new amplifier with the OEM existing speakers before I go to the next phase for speaker replacement. The sound quality is surprisingly good. The new amp has much more punch and the MB Quart crossover works pretty well with the factory woofer.
• Reinstall driver and passenger seat
• Reinstall console
• Finalize installation of radio
• Open an adult beverage of your choice and listen to your favorite song using the upgraded system

See picture 6 for final installation before re-installing the seat

bart1

Just glancing over, this appears to be awesome! Thanks! I will print and study, as I will be adding an amp soon - SS Stealth was on my list of potentials.

The Eagle

thanks!!


~ The Eagle ~
---------------------
'96 Polar Silver/Black C4S, manual, litronics, LED's in the positioning lights, alu/leather shifter & handbrake,
silver face gauges with alu rings, "GT" sport seats, full leather interior, motor sound airbox, stainless door sills,
front protection bar, with split rear grill and layered with Meguiar's NXT Tech Wax
__________________
'92 Carrera 2 (Sold)
'89 Carrera 3.2 (Sold)

MarkD

Wow, very nice write-up sir!

2Many Cars

Just as a point of clarification, do you have the Nokia sound control panel in the driver's side door pocket? If you don't then you have the hi-fi system but not the DSP system. DSP (Digital Sound Processing) I believe was an option over and above Hi-Fi option and DSP added a mostly useless sound control in the driver's door panel. I'm sure you could do without the Nokia DSP panel but I suspect it makes the wiring a bit more complicated than described here. If I'm way off base with this assumption please let us know. I just don't want people with the DSP to get messed up if these instructions really only apply to Hi-Fi set-ups.

Great job on this. Thanks for writing it up.

bart1

Other good small amps:

- JL Audio HD Series
- Arc Audio Mini
- Audison
- Kenwood digital

e9stibi

@2Many cars - I have hifi option with DSP but the DSP unit will be taken out of the driver door when I install the speakers.

techsis

Thank you for consolidating all this great information. I will likely be upgrading the audio in the 993tt that should be delivered to my home in the next 14 days. The ability to restore the car to stock is key and you address my concerns.

Thanks again!

DocTock993

Wow! You are writing a painstakingly detailed reference work!
Thank you for your efforts both with research and publication.

zone5

e9stibi --Great write-up!!

When are you going to install the speakers?

You have two crossovers (one on each side) for the mid and tweeter and one additional crossover for the two woofers -- that's a total of three crossovers -- not a problem?? I have never heard of a system with more than two crossovers.

Also, you are going to mount 6.5 inch woofers where there are now 5 inch woofers, does that mean that you are planning on fabricating new enclosures? I was going to pull the trigger and order the same speakers that you have, but hesitated because I am not sure I will have the expertise to fabricate an enclosure.....

Thanks for the info you've provided to the rest of us --

e9stibi

@zone5 - I will do the speakers some times later this year. I have some other projects first like an oil change, replacement of CV boot and most importantly a duplex doghouse for our backyard. And with the DE weekends it might slip a couple of weeks. The good thing about my approach is that I can use the upgraded amp with the old speakers.

To the crossovers: A typical 3 component system should have 1 crossover for each channel. However, the MB Quart solution is a smaller 2-component system where you add a woofer which adds a crossover making it 2 per channel. Because of the size of the crossovers, I was concerned to place both of them in the doors. Another advantage is that I could use the cabling exactly like it was used out of the Nokia amp.

To the speakers: I know that I will make them fit under the factory hifi grills. There will be some kind of adaptor that I will create out of plywood as soon as I have disassembled the old installation. It will not be pretty but will serve the purpose of not cutting anything and ideally not drilling any extra holes into the sheet metal.

zone5

Thanks -- so to be sure I understand, the woofers each have their own crossover -- there are two channels (left and right) and two crossovers per channel for a total of four crossovers? I know it's a dumb question but want to be sure --

Also wanted to ask what you thought of this Blaupunkt amp??? -- http://www.crutchfield.com/p_023THA1...unkt+amplifier

It has an aux input, which i'm hoping will allow an Ipod to be played through the system which has a CDR-210 (which is what I have). According to the Blaupunkt website, it has an adapter that fits the 993 -- not sure if you had to fiddle with yours to make it work.....

kbrewer

e9stibi-Thanks for the info . Trying to decide on upgragde for my 96 cab. Did you ever post the part 2 speakers?

alcanada

Great write up.... makes me want to buy everthing you bought now and do the installation later.... maybe a winter project next year.

Patiently waiting for the final installlation so that you can give us your assessment of the sound system.

Thanks.

e9stibi

I did the final installation and are very happy with the result. There is enough "punch" in the system for my taste that I do not need any subwoofer. The outside mirror are vibrating when I crank the system up ...

I never wrote something about the speakers but this album with plenty of commentary should do it:

http://s482.photobucket.com/albums/r...ker%20install/

It might be difficult to get the MB Quart "made in Germany" but the current models should do it too. The Chinese got all the know how.