Soundproofing project

N

niilo

Member
The one gripe that I've always had with my TDi has been the amount of road and engine noise transmitted in to the cabin. There's not a great deal of soundproofing on the A2, which of course has its benefits in keeping the weight down for better fuel economy. For me though, I'd happily sacrifice a little of this for a bit more comfort.

So recently I decided to soundproof the interior and have covered most of the floor, doors, wheel arches and boot with sound deadening sheets. I was sceptical as to whether this would make much difference, but wow what an improvement! Road noise has been greatly reduced and there has been a noticeable reduction in engine noise when the car’s out on the open road. But around town the litlle diesel unit still makes a hell of a racket. I think it's going to be hard to improve things with engine noise - I'm sure a lot of the noise is simply coming out through the bonnet and in through the windscreen. But as a final thing to try, I was wondering whether it would be worthwhile to do the underside of the bonnet too.

Has anyone sound-proofed the bonnet of their A2 and did it make any difference to the level of engine noise?

Any recommendations for a good sound-deadening material that is suitable for use under the bonnet?

Cheers, Neil
 
you can get a hood lining kit from a proper car audio shop (not hellfrauds). You should already have a sheet of this on the bulkhead (engine side) but it may be worth removing the dash and putting some dynamat or similar behind there. Get a can of the spray on sound deading for areas you cant put a sheet but will still like deading. Did you do the roof?
 
There is no point in soundproofing the bonnet, as the engine compartment effectively comes about 2 feet into the cabin, because the windscreen comes so far forward!

Alex is right - you really need to remove the dash and soundproof behind there first, and also the roof if you have a tin top, as there's nothing other than the headliner.

I've always found my TDi to be pretty civilised, certainly compared to other cars of a similar size. The 3-pot engine will always be a little more intrusive though, due to its firing order.

Cheers,

Mike
 
Thanks for the advice. I recognise that removing the dash is what I’d really need to do, but I’m wary of dismantling where airbags are involved. I removed the glove box and the panel below the steering wheel which gave a limited amount of access to the lower bulkhead and soundproofed where I could there. That will have to do.

Considering what Mike said, I can see his point that it probably wouldn’t be worthwhile adding the extra soundproofing to the bonnet. I'll just leave it as it is.

Anyway, I’m more than happy with the noise reduction that I have already achieved. It's given the A2 that extra bit of refinement and makes it all the more enjoyable to own and drive.
 
I dont find mine noisy at all unless the windows are open.
I can only just hear the engine and that is one of the things I love about the car, its little engine roaring away!!!:)
 
I suppose the door and wheel arch made the most difference? I'm interested in sound proofing my car too. What sheet did you use? How thick? I'm about to take my dash out so I might as well do something while I'm at it!
 
Humps,

The sound deadening I used is the same material as mentioned in a couple of other posts in this forum as the "Partco" sound deadening sheets. However, I bought mine online from the Bodyshop Warehouse. They sell the same stuff. It comes in two sizes - 50cmx50cm or 20cmx50cm (10 sheets per pack). I bought 2 packs of the 50x50cm for around £20+Vat each. It’s quite heavy stuff so I limited myself to this quantity to see what I could achieve in noise reduction without adding too much weight to the car. This proved sufficient to cover most of the interior surfaces (except for the roof and the inaccessible bulkhead behind dash) with 1 layer of sound-deadening.

It’s fairly easy to dismantle the interior trim. Most of it is simply held on by clips. Just be careful not to damage the clips when pulling the trim off. I referred to the ElsaWin Workshop manual diagrams to identify the location of the clips and the correct removal procedure to ensure no damage was done.

When you remove the trim, carpets etc. you will see patches of Audi’s sound-deadening in key areas but there is a lot of exposed aluminium there which I thought would benefit from soundproofing. On the doors and boot lid there is no sound-proofing at all and it did make quite a difference to the noise level by covering these surfaces.

In terms of thickness, I only added 1 layer as this was sufficient for what I was trying to achieve - I'm not a car audio enthusiast or after a silent car, I just wanted to see if I could subdue the noise levels a little. If you were to add a second layer to the main noise transmitting areas such as the wheel arches, just bear in mind that you have to get the carpets and trim to fit back in place afterwards. Even with 1 layer added to the front footwells & wheel arch area, it was a tight fit to get the carpets and trim back in place.

When handling the soundproofing sheets, a tip is to leave them lying in the sun for a few minutes. It softens them up nicely making it very easy to mould them to the shape of the panels in the car. They can be cut with a stanley knife or big pair of scissors. They have a strong adhesive backing so fit very securely in place.

Hope that helps and good luck!
 
Use a roller and a hot air gun. Also use small strips as the smaller piece you use the easier it is to shape to the car.
 
Use a roller and a hot air gun. Also use small strips as the smaller piece you use the easier it is to shape to the car.
 
Niilo, thanks for the tip. I knew there wasn't any proofing at the doors as I can always hear my speakers from outside of the car, even when the volume isn't too loud. I think I'll order some sheets and do the doors. I drive a petrol, so the noise isn't too bad from the engine so I'll leave the front bulk head alone.
 
I refresh topic.

I would like to do a better soundproofing in my car. Anyone have a photo with how to look soundproof under dash?
 
I am planning to stick some dynamat rubber like stuff to the inner door panels and boot panels to reduce resonance, I am hoping this will make some difference.


Oh I know that Tony from A2 cars in Milton Keynes did an extensive soundproofing job on his car.

Max
 
I bought a real of this to do my doors and front wheel arches and floor footwells , Audi did put a few odd bits of this material under the carpets but i plan on totally covering the insides of my A2 to dampen the road noise , ive used this material in the trade for many years and very easy to apply, just cut to size with a stanley knife first, you may need to make templates for awkward places, then heat up the sticky side gently with a hot air gun, until it becomes warm and slightly softened, and push into place , and reheat lightly where needed in the knooks and crannys.

http://www.ebay.co.uk/itm/261420120036?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
 
JIGSAW said:
I bought a real of this to do my doors and front wheel arches and floor footwells , Audi did put a few odd bits of this material under the carpets but i plan on totally covering the insides of my A2 to dampen the road noise , ive used this material in the trade for many years and very easy to apply, just cut to size with a stanley knife first, you may need to make templates for awkward places, then heat up the sticky side gently with a hot air gun, until it becomes warm and slightly softened, and push into place , and reheat lightly where needed in the knooks and crannys.

http://www.ebay.co.uk/itm/261420120036?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Click to expand...

It's only 1.5mm thick? Is that typical? Is there any data as to how effective this material is? I think that the most effective area to sound-deaden is behind the dash and between the engine compartment and cabin. I am soon about to remove the dash, so that's going to be an ideal time to access that area and to apply sound-deadening! I'll need to ensure that the dash does re-locate, though, with the additional thickness of sound-deadening .... So 1.5 mm would probably be helpful, here? Where else have you intended to apply this, please?

David
 
Mass is what blocks sound, you really need to completely cover everything with something of around 5 kg/m.

Those self-adhesive Dynamat-style sheets are really designed for stopping panel resonance.
 
Hi David,
after spending many years in a body shop repairing cars this material is the stuff we used when ever replacing pannels, even our A2's have tiny peices under the carpets hear n there, but no where near enough, prob due to the weight it may of added.. youl find all high end cars are covered in this type of material and a heavy spray on sealer type material totally covering the undersides , simular to our own A2s..

I can take some photos over the next week as my A2 is ready to rebuild, put back together as its stripped out at present, not carpets , dash ect, and been that way for a while now, yes you can hear the turbo playing it tunes quite happily and every bit of road noise as the carpets are heavily sound dampened on the undersides...

basically at the front where your feet would go , youv got the curved wheel inner arches, i plan on totally covering these areas as audi only place 1 measly peice plus covering the front floor area up to near the underfloor access pannels, the same at the rear , totally cover the wheel arches.

then theres the doors, you will need to remove the trim and pannel and then the glass surround frame to leave a bare door, then cut a template that fits about and 1in from the sides and cover the inside of the door skin, i would not advise adding any other sound deadening material insides the doors themselfs as water needs to pass through from the top glass seal to the drain holes in the bottoms of the doors..

then depending how far you want to go , you can cover the whole floor from the boot forward, and even the under floor storage , but there i was just planning to fill with some left over foam underlay from a laminate flooring as i can just scrunch it all up and fill up the spaces , then easily removed if need be ..

you could go even further by removing the stone guards and covering the outsides aswell but i think that would be OTT and doing what ive discribed already will make the car totally different and eliminate alot of the droning road noise..

there is also several big voids under the dash when its removed at the tops and lower down behind the glove box and fuse box,,, BUT BE WARNED !!!!! YOUL have to make sure what ever you put in these areas does not have any way to interfear with the stearing or brakes and is fixed securly..

Regards Gary
 
Philip said:
Mass is what blocks sound, you really need to completely cover everything with something of around 5 kg/m.

Those self-adhesive Dynamat-style sheets are really designed for stopping panel resonance.
Click to expand...

Gary, can you comment on this input from Philip, please? I tended to be thinking on those lines, too ....

David
 
yes philip is correct , the tar material strengthens the thin door pannels too , but it also acts as a barrier to the sound waves, a few years ago we built a flat into the upper floor of a new build comercial unit, this had to be done to code and tested afterwards before it was signed off... basically we had to cover the whole insides with a rubberised sound proffing matt and then float the flat on the insides without peircing through the rubberised material, floors studwalls all built floating as such to gain the best sound barrier, this is not possible on the insides of a car so all you can do is use materials that absorb sound like the tar based material as its acts as a barrier of such, youl never remove all the sound coming into the car interior all you can do is dampen it and lower the decibels. theres loads of differnt materials out ther with silly costs to go with them too, now its all a case of how far you want to go and with our A2's how much extra weight you want to be adding. .
the real of material i posted the link to weighs 5kg , to do what i need will be about 2 reel 10kg and having gone this route before with great results which i was happy with and suited my needs, with the added bonus of giving that extra weight to the doors too which gives them a real beafy feel too when closing which was also to my liking, you could experiment and only go half way up the doors and do a part at a time to see what improvement it makes and add more until your happy, due to more material more weight ect ect, but at the end of the day its how far you want to go and what level of sound you want to end up with, im lucky i live out in the sticks and rarely get on a motorway, as found it awefull in my A2 on motorways, and showed up how little sound deadning there was, the constant thump thump thump was too much for me and even the radio wouldnt drown it out so as i said its all to your own personal taste in how far and what materials u use...

gary

This is the material we used, but ile warn you it weighs a ton and aint light..

http://www.soundstop.co.uk/ZISBM6MM.php
 
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