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Sound deadening/proofing a 993

TobesEtc

Well-known member
Joined
2 Jun 2014
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1,849
My 993C4 is a regularly used car, not a shrine to originality. I take the view that Porsche built a fantastic car but that in the 20 years that have passed some of it has deteriorated and technology has progressed. I drive the car on occasional long trips (it's been to Le Mans this year - great fun) and will probably visit the South of France next month. On those drives I want to be able to hear the engine and my stereo, but nothing much else. Those of you who think that a Becker through aged Nokia speakers is the only way, please look away now, you won't like this! Anyone who wants to know how good a 993 can sound, please read on...

I have replaced all the speakers (JBL rear, Morel front) and the head-unit (Kenwood) but still found that the sound was disappointing. So sound-proofing was (one of) the logical next step(s). This work and the stereo upgrade was all done by www.enigmaaudio.co.uk in West London, to whom I am very grateful.

The first thing was to remove the door cards. Behind them the old door liner was torn and taped-up with masking tape. Having removed and discarded the old liner, in the door, old "brown bread" insulation that had fallen off the door and was just sitting in the bottom of the door. The pics don't really show that in the door but there was loads of old hard, cracked foam just rattling around inside the bottom of the door.

After each door was cleaned up, the outer skin was lined with sound proofing (stuff like Dynamat but actually http://www.fourmasterscaraudio.co.uk/store/skinz/) as in pic 3 before a dense foam was used to neatly line the door interior. Then each "hole" in the inner skin was covered with skinz before a new door liner was applied and the door cards and fittings replaced.

One of the few things I don't like about my 993 is that at m-way cruising speed there's an irritating drone from the rear bulkhead/engine bay. So we decided to sound proof that as well. The rear seats and interior was removed, Skinz applied to rear bulkhead and sides, lined and all put back together. Simples! (well, simple for me as someone else did it). Pics also attached. The eagled-eyed among you will spot a silver 993 Targa in the background having something else done.

So - what's it like? Well, the first thing is that it is not visible in any way, but it is instantly noticeable. Close the door and the shut is much more solid. Tap the door and the knock is utterly solid. Inside, fire up the engine and whilst the engine noise is surprisingly unaffected, as soon as you start to move you notice a huge reduction in roar noise, rumble & rattle. It's really like a new car. The effect on the stereo is equally profound. Making the doors more of a sound-box lets the Morels work properly. They kick out deeper bass, richer treble and because they are competing with less noise then you don't have to turn the volume up as high. Everything is just better. I've only just got the car back but already I am delighted.

(Had to cut a couple of the pics as I can only add 7)

So, a huge thank you to Sylwester and his team at Enigma Audio.
 

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Excellent article, thank you.

Are there any pictures of the finished installation, especially the Morel speakers. :thumb:
 
Hats off to you. Nice job.

I think the 993 is already pretty well soundproofed in an upmarket sports car-type way, so you must have good ears.

I do smile however when people say "I like to hear the roar of the exhausts and the engine, so I turn the stereo off and open the windows"

All they'll ever hear is wind-noise, unless they are going through a tunnel.
 
Its the tyre noise that's the killer on Uk roads :nooo:
 
Very true about the tyre/road noise - and that's one of the funny things about this work - it has cut that noise out and the engine noise actually sounds cleaner with less resonance/boom in the cabin.
 
I've been doing some prep on mine before the RS carpet arrived using Dynamat and closed cell foam. Dynamat is quite heavy, how does your stuff compare? I've found that you don't need much too replace the original sound deadening with the same effect but lighter and doesn't soak up water which is impossible to dry out in situ.
 
Skinz is almost identical in make-up to Dynamat (at least visually to the layman - ie me) but Dynamat have put up their price and dropped the thickness by a mm (despite claims to the contrary, comparing old-to-new shows this to be true). So we used Skinz because it is much cheaper and at least as good as the brand-name.

With regard to how it compares to the old material - as you'd expect, 20-year old plastic tech to compare to new tech. Take a look at this pic. It is the old sound insulation out of one door. It was all hard, cracked and had fallen off and accumulated in the bottom of a door. It's very heavy and was doing nothing. I suspect it was always heavier and not as good as the new Skinz/Dynamat products.

The new materials (which ever brand you choose) are simply better than the old materials. I'm sure you can replace the material in your (Endoman's) car with much lighter, more effective and waterproof material. Go for it! Got any pics of your work?

You can see more pics of the stereo upgrade & parking sensor install here:
https://www.facebook.com/media/set/?set=a.812767495402795.1073741851.174555525890665&type=3
 

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Hi Tobesetc, this is very cool...

I agree with your approach... The engine noise and exhaust note is great, but being able to block out some of the other wind/tyre/traffic noise would be great.

OK another thing that just got added to my list.

Would you mind sharing how much this cost? or alternatively if you can PM me.. I guess you got the speakers and everything done at the same time.

I need new front speakers but that's it... I think..
 
Good write up! I'm hoping to do something similar in my car.....being a cab it's a lot more noisy and on top of that I have a annoying squeak from my passenger seat!
 
Actually did HU & speakers first, then went back and did sound-proofing afterwards. Mistake, should have done all at once. Will pm you, cambjones.
 
No, the parking sensors are only on the rear bumper - but they work perfectly, just like any new car. Excellent addition, parking on a street it's so handy to have these!
 
Great thread, thank you for taking the time to photograph the work.

Did you buy all the soundproofing material from the same firm?

What was the cost of the kit you got

Thanks

Ash
 

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