RicardoD

The last step for me to turn my 1991 C2 Tiptronic into my daily driver is to upgrade the stereo and see what I can do to reduce the engine & exhaust noise. There is a time and place to hear my 964 engine that I worked on for over a year to run beautifully, but my daily commute is not where I want that all the time. The tip allows me to zone out as required and just chill on my drive home.

I will use this thread to document my install over the coming days. First here are the threads I read in preparation:

Door panel removal: https://rennlist.com/forums/964-foru...val-guide.html
Installing rear speakers: https://rennlist.com/forums/964-foru...-speakers.html
964 audio install: https://rennlist.com/forums/964-foru...o-install.html
Guide to fitting front component speakers: https://rennlist.com/forums/964-foru...-speakers.html
Alpine Stereo Upgrade (good wiring diagram): https://rennlist.com/forums/964-foru...grade-cab.html

First thing I did was browse Crutchfield.com to get a sense of various head units, amps, and speakers. Then I called Rod Birch at Car Audio Innovations: http://caraudioinnovations.com. Rod is a air cooled 911 enthusiast and knows the 964 well. He makes a real nice 964 subwoofer package that fits in front of the rear seats. I called him about the subs and he emailed me a very nice 964 audio upgrade document that walks through coupe or convertible 964 options. He has over 20 years in the business and I could tell. He started out with some very high end audio recommendations but then worked with me to hit my budget based upon my initial research. He was able to confirm or recommend alternate components that he felt would work better. I ended up buying my entire audio package from him including one of his subwoofers. (I drive my kids to school and I need the passenger rear seat and legroom free for my son). I am also buying his support through the install which is nice to know.

I ended up getting:
- Alpine CDE-HD149BT
- JL Audio XD400/4 amp (2 channels to drive front speakers, 2 channels bridged to drive one subwoofer, head unit will drive rear speakers for fill).
- Focal PS 130 compnent speakers, 5 1/4"
- Infinity Reference 4 x 6 in the rear (these are from Marc Shaw who is the man!, you can see them in the thread reference above, he ended up taking them out later when he turne his 964 into a track beast)
- 1 custom JL audio 8" subwoofer, in an enclosure, with matching cashmere carpeting for my interior. Looks like this but in Cashmere: http://cai-store.com/products/89-94-...package-sec964
- full amp install wiring kit from Rod setup for my 964

RicardoD

Since I have the rear speakers already from Marc Shaw (did I mention Marc is the man!) I started there.

Follow Mark's instructions for installing rear speakers (link in my first post) which shows you how to remove the rear trim panel. Then i took it a step further and removed the rear seat belt anchors on the sides of the vehicle. There is a trim piece that slides off and its a 17mm bolt that you remove. This will allow you to remove the rear trim planel completely from the vehicle. Note you don't have to remove the rear seat belts, you can complete the rear speaker install with the rear trim still in the car.

Since I am also interested in improving the sound insulation in the rear of the car (to cut down on engine noise) I am going to install Dynamat on the rear deck and then replace the factory sound insulation. That factory insulation piece is really floating over a lot of rear deck in the back. I ended up ripping all the existing rear sound insulation out of the car. To do that properly you have to remove the side trim pieces. There are 4 obvious screws on each top side trim piece that you unscrew and then remove the trim. This will free up the side trim pieces to be removed.

Before you remove the rear deck sound insulation you should remove the rear wiper if you have it. I didn't know how to do this when I started but found the link on p-car.com and its pretty simple (see my attachment photos).

With the rear wiper out of the way just grab and start ripping out the rear sound insulation. The rear seat back have a carpet flap is screwed into the car. Remove those screws and fold back the rear seat carpet to get better access to the bottom of the rear sound pad insulation. Don't expect to re-use the factory rear sound insulation pad. You have to rip it out.

Edit, both sets of seat belts have been removed. You have to remove the front seat belt lower outer anchor to remove the side trim panels. I am changing out my front seat belts (frayed in some areas) as part of this project.

RicardoD

Now I have an uninsulated rear deck covered in sticky factory glue and bits of foam here and there!

Did I mention that Marc Shaw is the man?! Because he said the mineral spirits work best at dissolving the 964 adhesive. I bought a can of the odorless mineral spirits and stared with some plastic scrapers and elbow grease and some rags. There are lots of threads with people using nasty solvents and respirators. It was very simple and easy for me to get mineral spirits and the odorless version means you are not dying breathing toxic vapors.

This is still a pain in the *** and even through I could probably get away with putting the dynamat over the existng old adhesive, I decided to take the perfectionist route and spend a few hours scraping and wiping all that crap off.

After picture will be posted when I'm done.

Streetdaddy

Watching this thread with interest. My new 964 has nice stereo( mb quart speakers and rockford fosgate amp, but doesn't sound very good. Virtually no bass) man, that is a lot of work to add the dynamat!

UncleRemus

I've done this twice. IMO, you should rethink your plan. Dynamat is not the only option, and you need/want a barrier layer.

UncleRemus

edit: I went with these products:
http://www.b-quiet.com/ultimate.html

Streetdaddy

Where all did you put it? Was it worth the hassle?

swftiii

UncleRemus - tell us about your impression of the b-quiet barrier and how it has helped with heat and sound control.

I'm planning to have new carpet installed soon and want to clean up the sound deadening/barrier layer on the way so was considering otehr products (hushmat?), but this seems more affordable and thinner.

Thanks,
-Skip

RicardoD

Streetdaddy, I'm not done yet, those pictures are from yesterday, I'll keep posting and let people know how it goes. I hope I don't end up just going in a big circle with no real noticeable difference.

Streetdaddy

Ricardo, do you have the suspension tuned for a softer ride since this is your dd? What are you running?

UncleRemus

I've done it to a C6 Corvette and my ls2 miata. IMO, the most noticeable impact is the reduced cabin heat. I am very sensitive to drone and road noise, and I did notice a reduction in noise. But, by leaps and bounds, the interior of my two cars never transmitted as much heat.

Edit
I put the b-quiet ultimate everywhere on the interior, and added the barrier layer in certain spots, in particular the rear and floors. IIRC, I went with b-quiet based on an old sounddeaderershowdown.com test result, weight, and cost.

I found that it made my cars much more pleasant and I can tolerate longer road trips with it.

RicardoD

Streetdaddy,

My suspension setup is the stock one and I love it. To me its a great compromise, terrific handling but a reasonable ride. I am also running 16" Design 90 wheels which I like very much and i am sure helps with the ride comfort.

RicardoD

I got the rear deck cleaned up with my plastic scrapers, mineral spirits, and a rag. Now on the more vertical part behind the rear seats. Urgh.

In the meantime I did order a new factory rear sound pad. The parts department at Sunset Porsche told me that part number 964 556 239 01 has been superseded and it now comes in two pieces:

Upper part 99355623902
Lower part 96455623904

I will use these as a template to cut out the dynamat I intend to put underneath.

Mixter

Great thread....looking forward to your install. I just bought a Rockford Fosgate PBR300X4 amp that I'm planning to install under the passenger seat and am looking to upgrade my speakers.

N24

"rear offsett grommets" brilliant!! I found two of these rolling around the footwells of my car - now I know where they belong! thanks!!!