Decreasing level of unwanted noise in a automobile

[jtbo]

This is thread for any make and model, I know here are some people involved to car audio stuff, should be good for them too, my priorities however are getting rid of tire and engine noises, goal is pretty much the same.

Here is what I have gathered so far from the Internet, sorry that this is bit of Finn side, however you should be able to workout products used in your local area without too much of trouble.

My project in this is unfortainly not the 300, but car I sit many hours in a week, Citroen ZX TurboD Wagon type. With 300 all should apply, but additional to means is getting rid of wind noise, roof rails, door seals, mirrors are areas that need work in 300 to get rid of that.

So basic idea is to increase mass of metal parts of car, which should make resonating frequency lower and also limit the power of resonating which will be felt as lower noise level.

I have gathered that bitumen is rather good, but nowdays 4mm bitumen is expensive, heavy and pain to work with. Today stuff to use if you are on budget is STP Vibroplast M1, which matches to 4mm bitumen, but is very easy to work with and hugely effective compared to it's weight.
For better result you can use more layers or STP Bimast which is like 3 layers of Vibroplast, however this is harder to work with and is not very cheap, good for example to wheel wells and such.

Place to buy this stuff is perhaps this:
http://www.autosound.ee/eng/home/catalo ... sories/94/
Price is good, over 150 euro orders come without postage, don't know if you guys know better places?

Also I found this place with good pics, use google translate to read, but I guess pics tell it all, lot of work:
http://kalliojarvi.net/ibiza/vaimennus/index.htm

Then here we have stuff called Katepal 36 (found from hardware stores, here K-Rauta, Rautia, Agrimarket, Bauhaus etc, get 10l container, price is much lower and you will need it a lot to make good riddance of tire noise), it is sticky like mud and it is bitumen, you use it to wheel wells, wheel side of wheel well and that can be put to place with painter brush or plastering tools (sorry, my limited english words are not helping to describe, post to ask if unclear). Stuff servers 2 purposes, it removes tire noise and it protects car metal from stone chips, all the rust must be removed from both sides of wheel well before applying that, naturally also painting etc required before applying stuff as it will not come off very easily if even at all, waxoil yearly (with thin oily stuff) to keep it good for unlimited years.

My plan is to get Katepal and Vibroplast, and apply them before end of month, hopefully, only trouble is that I don't have warm space and applying stuff requires warm space, however I have a garage so I might temporarily modify it a bit to make it warm space, if all goes well I try to make photos / story from it, however I'm lazy and there are lot of dismantling required, so this thread is mainly for helping me get on with it

Well, maybe this is some of use to some of our members, post questions and if you have some other ideas/disagreements whatever.

[volvodspec]

at my work the terminal tractors are a selfbuild product http://www.terbergbenschop.nl/uk/produc ... s_open.php, the noise of the 6 in line turbodiesels is enormous if a tractor is driving by and we don't want to give the drivers the same noisy working enviroment, so the cabin is isolated with foam. if you're inside the cabin and close door/window while driving it is impressively quiet leaving a slight humm when giving full throttle. this is done by placing 25/30mm thick soft foam isolation under the cabin (above the engine), along with proper seals for windows/doors etc. http://www.merford.nl , manufactorer/developer of all sorts of cabins and isolation/fireproofing is the supplier of that isolation, a example of what we use can be found here http://www.noisecontrol.nl/acusticell_vsp.html

my idea is dat if you apply that type of foam isolation on the firewall and let it run until you're under the seats you're halfway there. a thinner type of isolation (10/15mm) can be placed on the inside of the doorskins and on the chassis behind the front seats. also the 15mm isolation can be placed instead of the current headliner isolation.

i believe it has better sound deandening properties than bitumen floormats, and it weighs practically nothing. i don't know what it will cost but i can imagine it is rather expensive.

[jtbo]

Very thick material is bit of problem in cars, I have found that there are many places where even 10mm is too thick. That Vibroplast you get effect of 4mm bitumen with only 2mm very soft and easy to work with layer, 2-3 layers above each other gives some notable difference, but of course nothing compared to what you put to that machinery, however 4-6mm starts to be maximum what fits.

On straight part of floor some thick material fits and is good, but those areas are rare in this car, so have to make compromises

One of key places to put sound dampening material is bonnet as engine noise travels trough bonnet and trough windshield, smaller part comes trough firewall, but there is sound coming trough there too.

[volvodspec]

why is it a problem Jani?, it has its own sticky side to stay in place, you can make a template first to cut out any bolt holes and the foam is quite easaly compressable if brackets are placed near the holes. i see it fit in a 300 quite easaly not compromising any original mounting points.

[jtbo]

why is it a problem Jani?, it has its own sticky side to stay in place, you can make a template first to cut out any bolt holes and the foam is quite easaly compressable if brackets are placed near the holes. i see it fit in a 300 quite easaly not compromising any original mounting points.

Well, stupid french designer has designed centre console, dashboard, floormat mounting and all that with so narrow space that it would not be possible to mount stuff back. Also I now already have my shoe tops touching underside of dashboard, it would be problem with 30mm decrease of space too.

Rear seat are specially might be a problem, I think.
http://kalliojarvi.net/ibiza/vaimennus/va-3-6.html
http://kalliojarvi.net/ibiza/vaimennus/va-3-7.html

-6db / 2mm is how Vibroplast has been performing in tests, it is quite cheap (22.30€/m2), imo and easy to obtain here, so that is why I think of using it. Of course as I have read many of experiences from it, I can trust that it works well too.

I did read that Acusticell VSP is bit over 64€/m2, it is also putting me away from product for now.

[jtbo]

Place where I try to put some pics:
http://jtbo.pp.fi/images/album/ZX/soundproofing/

Boot lid is made of plastic, it has plastic cover and it sits rather close to boot lid in large area, can't think of way how to fill that lid with stuff as cutting would compromise integrity of lid.

At boot there is one very soft and inch thick mat that sits top of metal floor, metal floor is curved so no straight surface. Also there is one full size thick rubbermat. Metal floor sounds like drum.

Rear door has small piece of some 1mm thick bitumen to make it stop vibrating, most of door sounds like a drum still, also inside part of door is really loud drum
There are access to door, but not very good access as you can see from pics.

[Fuse]

Yeah Vibroplast is quite good and very nice to work with.. I did my soundproofing it was ~0C degrees outside and I didn't need a heatgun to apply the Vibrplast sheets so it's very easy to install and doesn't crack like bitumen.



I might put on another layer sometime but then again it's not a hifi car so... I also replaced the original foam mats which absorb every bit of moisture with Splen 3008 mat, it's also made by StP. It doesn't absorb water at all but reduces echoing etc... as good as the foam mats.

http://www.powerset.fi/autohifi/tarvikk ... n3008.html

Dynamat is similiar and performs a little better but is way more expensive so I chose Vibroplast also...

[jtbo]

What a mad price at Powerset shop, 50€ for 10 sheets of Splen 3008, when you can get same amount for 23,89€

I don't know if I can make all things fit, but two layers of M1 and one Splen 3008 sounds good for floor.

Don't know if I will make all those things at once, need to source lot of those small mounting clips, they seem to be lot more fragile than in Volvo as when I did take out rear door panel last summer, I managed to broke 80% of them at warm day. That is even I have been trained to remove panels in a garage and I did use proper method, however I had only pair of screwdrivers to work with, proper tool is thin long iron 'fork', maybe I can make one out to save bit in cost. Those mounting clips are almost 3 euros / each

I managed to fit hose to expanding sealing foam bottle, so managed to put stuff inside to boot lid, it mainly removes echoing higher pitch sounds. Then I put some soundproofing mat between boot lid and boot lid plastic cover, it was quite tight fit even that is something like 8mm total. It made some difference, now exhaust note is gone and some echoing is missing from rear of car. It does need proper theatment still, perhaps one layer of M1 and one 3008 if I can squeeze those between panel and lid. I have quite extreme mod in mind too, as that plastic cover of boot lid is quite large straight plastic surface, it does reflect sound waves quite well, I have one piece of some 40mm thick sound absobing material, it is composition of 10mm foam 1 or 2mm bitumen and rest again foam. I plan to use spray glue and glue that to boot lid cover, it surely stops reflecting sound waves, foam is also nearly same cover as are interior plastics so it will not look too ugly there, I probably make corners round so it matches well to shapes there.

Doors and front fenders seem to be quite large sources of noise in this car so that is where I focus next.

I have only lame excuse for no photos, I did forget where my pocket cam was, afterwards found out that it is in my pocket Must take pics when I add news stuff to boot lid.

Also managed to trip over because of loose shoe lines (is this right word?) that caused nice chain reaction where pile of old winter tyres felled over car, result is two palm wide and some 3-4cm deep dent at front fender, just thing I needed, it was almost only panel without damage (car has had rough life before I got it). Boot lid and roof are now only panels without dents, boot lid is plastic no den't possible, roof surely is possible.Well that is just my luck.

[jtbo]

Here is latest progress:
http://jtbo.pp.fi/images/album/ZX/sound ... nt_fender/

There was lot to do before actual job could begin, needed to wash whole section to find where mounting clips of inner fender are, remove inner fender, wash inner fender from backside, was actual fender from inside. After that I could apply Katepal, which smell like paint thinner and smell gets worse every second when you working. Temperature outside was -8C in garage +3C so stuff was very very thick, I had to use car indoor heater to heat that bucket.













I think I should been washed it even better than I did, but it is too cold to use pressure washer and with sponge and bucket in +3C job is not most pleasant to do.

[jtbo]

http://jtbo.pp.fi/images/album/ZX/soundproofing/boot/

Before:


Now:


Sorry about bad images, my pocket cam's lcd display has been broken and I had accidently put it to high ISO, bit problematic to get it out from that.

That boot area needs a _LOT_ of materials, I believe that alone that left wheel area that is in photos took some 6-7 sheets of material and there is only very small amount of overlapping. With 40 sheets maybe possible do rear doors, boot wheel areas and boot floor

Good thing that I did bought 80 sheets

-3.5C in garage, sheets are rather flexible, but I did use heat gun for tricky parts as it softens sheets rather well, also I believe they stick better when warmed a bit.

Butylene with aluminium tape describes best of these sheets, so if someone has cheap source for butylene and aluminium tape, then it would be possible to make thicker and better material by yourself.

Black stuff is Splen 3008, 8mm thick camper's foam more or less, but is much smaller cell stuff, also feels very warm in cold garage, nice to keep under butt so cold car metal does not freeze ass while installing that stuff sitting inside a boot

I think that I will not install more Katepal until at summer comes, it is too cold now so that stuff is bit too thick, when it is warm it would be like painting wheel wells with it, would be good for rust proofing underside of car too

Silly amount of dismantling required to get access to all important places.

Oh yes, one problem, there is large air vent, that black thing with grille you can see in photos. Now what to do with that? from there sound enters to car very easily, but if I block then car ventilation will be even worse than it is now?

[jtbo]

Must continue tomorrow, too cold, too tired and too hungry

[jtbo]

I did complete boot and also bonnet is ready, rest of interior is next, just waiting weather to get bit better, -27C is tad too cold for my old bones.

Already it has some effect, noise is not so badly piercing type as it was before, also most of sound now comes from front and motor sound comes behind a dashboard.

Wheel wells at front are next, but that will take some time as it is so terribly cold now.