Sound deadening floor

[VR457]

Things to note in deadening interior -

Vacuum and wipe down surfaces first, tape up loose wires.
Apply different types of deadening materials because one type of material will only insulate against certain types of frequencies. With a range of materials you have a better chance of insulating against road noise, exhaust noise and bass induced vibrations.

Ensure the layers are put on big panels where the most vibrations / sound intrusions are likely to occur. Layer up and tap panel until its nice and dull.

When putting foam on, dont make it too thick and remember that the main carpet has to fit back on so leave plenty of play in the corners and sides.

Tape the foam and carpet layers down so they stay where you want them to after refitting.



These are the stripped pics of the interior - note the sparse sound deadening from the factory -

SDFA1.jpg SDFA4.jpg SDFA2.jpg SDFA3.jpg

The first layer - Silent Coat bulk pack.

SDFB1.jpg SDFB2.jpg SDFB3.jpg

The second layer - Foam! Got it from Dunelm Mill.

SDFC1.jpg SDFC3.jpg SDFC2.jpg

Final layer - Heavy duty carpet.

SDFD1.jpg SDFD2.jpg SDFD3.jpg

Results and thoughts: Made a lot of difference. Feel cocooned in the car now, the world seems somewhere out there. Bass is cleaner, sound quality is better as less waves diffusing, refracting, bouncing around and cancelling other sound waves. Tyre noise is still present, though at a much reduced rate. Would recommend putting more Silent Coat on the arches, front bulkhead. Floor seems fine though.

Should i have stripped out the old stuff first? I just left it in on the premise that more = better. Some recommend you take it out before putting new material. Do it if you think it will help.

[foxdie]

Great writeup and pictures, what was the total cost of doing this? Might do it myself

[VR457]

Not a lot. Silent Coat - £40? Foam - £15-20?. Heavy carpet (could use rubber mat / golf carpet) - £20, tape - £5.

Use more first layer than i have though.

[Davezj]

i am no expert on audio stuff but i have watch a lot of programs on audio installs,
personally from what i have read/watched about sound deadening i would have put somethimg like Dynamat over all exposed metalwork as you don't know what part actually causes the issues. on some cars they have been acusticly tested and know exactly where to put the sections of dynamat or equivilent to ancel out any vibrations and the like. but If you don't know where to put it you have got to put iteverywhere, over evry exposed bit of metalwork. in my old MKII escort it used rattle to buggery so i used bitcha mine roofing felt backing sheet that were great, and looked just like the dynomat installation you see today. but the bitchamin used to make the car smell like a new ly creasoted shed for a while, which was not a bad thing.
but as you have done, the more sound insulation the better. your carpet might be a bit lumpy, LOL. i have never seen foam being used on floor panels like that before, i can see where you are coming from though maybe you are onto something with the amount of faom you have put down.

nice write up though.

[VR457]

Thanks Dave. Looking at the pictures after a few months is reminding me that i had not put anywhere near the amount of Silent Coat that i should have. I went with the leftovers from doing the doors, which was done properly. When i get time i just might redo it again. It's not that the noise is bad, somehow i want it whisper quiet at 120 mph - no chance with the wind deflectors on!

[JamesGC]

nice work. ive started the long boring process of sound proofing my pfl legnum too. im only up to the trunk and roof area, but on mine the factory deadening has separated from itself in places leaving pockets of air inside , so ill have to remove it all first . i tried using dry ice and freeze spray but it didnt work very well. ended up using a heat gun + chisel + 200L of elbow grease, and citrus solvent to clean up the residue. ive also come across a different type of factory deadening in the rear quarter panels and a third type beneath the automotive insulation (nightmare to remove) on the roof.

[Nick Mann]

I want to do some of this soon. I have been perusing the bay of fleas for the adhesive matting - does anyone have any specific recommendations? It seems like Dynamat is overpriced to a non educated delinquent like myself.

I was looking at this: http://www.ebay.co.uk/itm/5m-Car-Aud...#ht_919wt_1037

[VR457]

You hooligan, sorry, i mean delinquent, the material you linked to could be no more than flashing tape. The general idea is a) thickness is king and b) variety is blah blah. So, try a brand like Silent Coat, a decent pack will cost about £80 and then buy things like underlay and foam with high densities.

From what i heard, you should take off the old insulation first, so a heat gun might come in handy.

[Davezj]

The only thing I can think of is the adhesive is bitchamin based so I would imagine when it is used in area that will get hot, it will smell.
Particularly the trans mission tunnel where the exhaust runs, not so much when you are moving but in stationary traffic it could cause an issue. The only real way to test this would be to buy so and heat it with a heat gun and see if it smells.

[The Vee]

When I did mine, I got those self adhesive bitumen type tiles from a bodyshop/motor factor supplier outlet. Still not cheap, but less than dynomat. Then other bits I got from a place called Woolies in Market Deeping who supply loads of things for mainly restoring old cars. I'll see if I can find a link.
Here it is
http://www.woolies-trim.co.uk/

[Nick Mann]

You hooligan, sorry, i mean delinquent,

Oi, I resemble that remark!!

Silent coat is between 2 and 4 times the price of that stuff I listed, depending on the thickness. They both appear to be multi layered and the "cheaper"(!!!!) adhesive matting in the Silent Coat range is only 2mm thick. The expensive Silent Coat stuff is also bitumen based. I'm not trying to argue, just trying to understand why the stuff with brand names is twice the price or more.

[Nick Mann]

When I did mine, I got those self adhesive bitumen type tiles from a bodyshop/motor factor supplier outlet. Still not cheap, but less than dynomat. Then other bits I got from a place called Woolies in Market Deeping who supply loads of things for mainly restoring old cars. I'll see if I can find a link.
Here it is
http://www.woolies-trim.co.uk/

Thanks Andy. That seems to be just as expensive as Jamils option. I'm not adverse to spending the money if I have to, but my understanding is that you can use over 50 spuare feet doing 4 doors, boot, bulkhead, floor and tailgate. That could involve spending £60 to £100 more than the stuff I linked to above. There's other stuff I could do with that money!

[Davezj]

Thanks Andy. That seems to be just as expensive as Jamils option. I'm not adverse to spending the money if I have to, but my understanding is that you can use over 50 spuare feet doing 4 doors, boot, bulkhead, floor and tailgate. That could involve spending £60 to £100 more than the stuff I linked to above. There's other stuff I could do with that money!

Here is a shot in the dark, could you use cork floor tiles or sheet to use as sound deadening.

You can get those very cheap.

1ft square tile 20 for £26

[Nick Mann]

Interesting idea, Dave. The dodgy cheapy stuff I linked to claims to be a multi-layer jobby that appears to be similar to many of the big brands. It works out slightly cheaper than the cork tiles you mention. Maybe the cork would be good instead of foam or felt?

[VR457]

I used flashing tape in my last car, B&Q has lots of it for cheap. The deadening was good initially but seemed to lose its quality after six months. It obviously suffered from the heat / cold changes in the car. Plus on warmer days it did smell which i liked but that's another story.

If you really want then try it as a sandwich layer between other stuff. You want mass loading and sound absorption; mixing and matching seems to achieve that.

[Davezj]

Interesting idea, Dave. The dodgy cheapy stuff I linked to claims to be a multi-layer jobby that appears to be similar to many of the big brands. It works out slightly cheaper than the cork tiles you mention. Maybe the cork would be good instead of foam or felt?

I was only suggesting cork tile as it was relatively cheap and is not bitchamin based, so not likely to smell. But only the adhesive to contend with smell wise.
But it was purely from a smell point of view I mention cork.

[Davezj]

I put a link up somewhere to a really good site that went into the do's and do nots with regard to vibration suppression, sound suppression.

I will see if I can find it tomorrow. Here you go, it is from Rouch,
http://www.roush.com/Portals/1/Downl...dAbsorbing.pdf

[Davezj]

Here is the road noise thread it came from
http://www.clubvr4.com/forum/showthr...leather+rubber

[Nick Mann]

Point taken, Jamil. I'll look at the Silent Coat and probably go for the cheaper end of their range that doesn't include bitumen.

Thanks for the links, Dave. The scientific paper is over my head. How do I apply the conclusions from that paper to the real world and the materials for sale? It seems to say similar to Jamil - a variety of materials is the best way forwards and mass gain is the best way to make a big difference.

[VR457]

If you're still reading then this series of tests of common products is worthwhile...

https://encrypted.google.com/url?sa=...DGrzNg&cad=rja