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Discussion Starter · #1 ·
The weather today was finally rather pleasant so I managed to install some Dynamat Extreme behind the rear seats.

As some of you may know I had a GTC Titan Zorst fitted before xmas and the sound is tremendous. That said, I was looking for a way to reduce some of the inherent resonance which I experience with both the Titan and my old Willall y-pipe.

I wanted to do this mainly because the low end frequencies caused issues with trying to film track days as it would overload whatever mic I used.

Method:

- Remove back seats and flip up central cup holder between seats (careful as there is a wiring harness attached)

- I used 4 packs of Dynamat Extreme Wedge Pack (around £25 per pack)

Dynamat Extreme Wedge Pack

- Time taken was about an hour, and the Dynamat was very easy to cut and place

- I covered any exposed metal showing once the seats were out, which involved the base and the backrest areas.


I will be adding Dynamat to the boot floor later on this week, so I will post if there is any further reduction in sound.

Results:

I used a sound meter from Maplins to check the before and after sound levels..

These are MAX recorded sound levels

Before:

Idle 79 dB
accelerating thru the gears 109 dB
Cruising at 70 mph 98 dB


After

Idle 74 dB
accelerating thru the gears 102 dB
Cruising at 70 mph 94 dB


These figures only tell half the story. My first drive after fitment was a real eye opener. The car now sound refined, little or no tranny noise, less road roar.

It's not surprising really when you see remove the rear seats and find no soundproofing whatsoever. That of course means there is nothing to stop any noise form under the car making its way into the cabin.

All in all, this is a simple addition which radically improves comfort levels in the car.

I highly recommend it even if you dont have an aftermarket exhaust.

As ever, any questions, just ask.
 

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Discussion Starter · #4 ·
the extreme stuff weighs around 2.2kg per m2.

I used about 4.5kg worth.

I'm not too concerned about weight in this case as I lost loads losing the OEM zorst.

I loked at loads of different types of soundproofing, but the Dynamat had the best acoustic properties at the frequencies I needed.
 

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CC

I'm about to do the same. Did everything come apart and then go back in fairly easily? Or is there anything I shoiuld be wary of?

Cheers
 

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Discussion Starter · #11 ·
Sorry no pics fellas.

Pics don't really add anything honestly. If you remove your rear seats (takes 1 min each side, plus one nut to unscrew) you'll see the parts to cover. As for the boot, just pull the carpet up.

This is one install that everybody can do without much help.
 

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Discussion Starter · #12 ·
CC

I'm about to do the same. Did everything come apart and then go back in fairly easily? Or is there anything I shoiuld be wary of?

Cheers
Very easy buddy.

Pull the tab under the bottom seat pad and just lift out the seat. Undo the one bolt at the bottom of the seatback and slide cushion up and out. Replacement is the reverse.

The dynamat is easy to install just place it in first and use a decent par of scissors to trim it to shape. Then just stick it down.

The boot is even easier. Lift up carpet to remove and the side panels are removed starting from the rear panel first. See my 4 light install thread for how to remove that.

If there are enough people interested I'll do an install run thru for the seats but it'll be a couple of weeks as Im in Anglesey next weekend for our driving weekend and it's dark when I ge home thru the week.
 

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Discussion Starter · #14 ·
Yes Ed, even you!
 

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Dampers like Dynamat are really for reducing panel resonance (turning vibrations into heat). If you want to effectively soundproof, you need a (heavy) barrier layer between you and the noise.

Philip
 

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Discussion Starter · #16 ·
Dampers like Dynamat are really for reducing panel resonance (turning vibrations into heat). If you want to effectively soundproof, you need a (heavy) barrier layer between you and the noise.

Philip
It depends upon your definition of "effective soundproofing"!

A reduction of 5 db for me is very good for my first layer, and without the boot floor being lined too.

Once I've done that, I may order some Dynapad to pop on top of the Dynamat.

Bear in mind that there is zero soundproofing between the floor skin and the rear seat.

Also my primary reason for doing this was to reduce low frequency resonance within the cabin and at this point I've succeeded.

More to follow!
 

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Dynapad is criminally expensive.

You can buy 5 kg/m2 barrier mat for about £7 per m2, a decoupling layer of closed-cell PU foam under it for about the same.

Philip
 

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You women...I have no sound insulation in my car. The way it should be. On fun short journeys you get to enjoy the sound of the engine, and on the long journeys with your wife, you can't hear her.
 

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Discussion Starter · #19 ·
You women...I have no sound insulation in my car. The way it should be. On fun short journeys you get to enjoy the sound of the engine, and on the long journeys with your wife, you can't hear her.

LOL!

:D
 

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...A reduction of 5 db for me is very good ...
5dB is excellent; dBs are logarithmic (sp?) so, for example, if you double the power to a loudspeaker (i.e. go from 10W to 20W, or 50W to 100W etc.) then you only gain 3dB.
 
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