yet another sound deadening thread

[vwlovr]

[vwlovr]

okay so i finally finished the entire floor...

AVG 96db --MAX 107
AVG 97db --MAX 108
AVG 96db --MAX 105

so total was...
AVG 96.3db -- MAX AVG 106.6db

so pretty much the same thing, i only did three runs because i kept hitting traffic. overall the van still sounds better, and the idle test shows some positive results..

AVG 83db -- MIN 80db -- MAX 86db

at this point the bare box van just can't kill the 5k-6k rpm of the drag race style run. i think a better test would have been at like 3k rpm in 4th gear or something. but it's too late now. at least i think the idle test might show some more interesting results.

i did try to pull my door in closer for a moment during a run and it definitely changed the wind noise. i think some new seals are in order.

i've also run out of material, i'm going to order another roll today to do the sides. i had enough to start one side, but that was it. i had calculated my needs based on only one layer, but i had doubled up on the engine bay, and that account for like 25 sq/ft. even at one layer, i think 3 rolls would be tough if you do the whole floor and sides.

in the front, i didn't pull the dash, but i did get a lot of material behind the passenger side after pulling out the glove box.

[vwlovr]

just a little update. since i'm trying to get my van finished for a road trip i couldn't wait for the last roll of b-quiet to arrive and i had to drop in my ragtop sunroof. i did a sound test afterwards to see what difference the top made.

to my surprise there was no measurable difference with the ragtop on and completely closed.

i did 3 runs which yielded...

AVG 96db --MAX 105
AVG 96db --MAX 106
AVG 96db --MAX 105

so total was...
AVG 96db -- MAX AVG 105.3db

the idle test was actually lower, which i would guess is due to the fact that here is a 40x40" piece of fabric where there used to be sheet metal. those results were....

AVG 82db -- MIN 80db -- MAX 85db

i also tested what the top was like fully open. the first test was fully open, with no side windows open. this turned out to be really loud because the lack of side ventilation created this crazy pulsing sound wave at like 60mph that practically hurt my ears. the meter showed a 108db average for that! ouch. the max was beyond the 110db limit. so loud.

so i did another run this time, top fully open, with both rear side windows open (my fronts currently don't open, another "joy" of power windows). that worked much better and gave a 105db average. for comparison i did another run, with rear windows fully open and top close which yielded a 102db average.

so overall not bad. i was very pleased that it didn't create extra noise when closed. even open the majority of the wind noise came from the front area of the van.

i did get the b-quiet in yesterday though and will be finishing the work for that this week. doing the sides and any exposed metal parts of the roof.

[pete000]

I would be interested in the total weight this adds to an already heavy vechicle.

I did the Dyna mat to my front doors because the plastic shields were junk. helped a lot.
_________________
1990 Vanagon RS 2.1
1967 Deluxe 21 window
--------------------
Koni Shocks
H & R Red Springs
Addco Sway Bars Front-Rear
18 X 7.5 and 18 X 8 OEM Porsche Wheels
Recaro Power-Heated seats

[vwlovr]

[second skin rep]

hmm...
The floor, so you know, is not the first place you should dampen if you have a limited amount of sound.
I see so many customers do this.
They buy our prodcuts and treat the floor. I guess the thinking is that the floor is closest to the road and the road is where the noise is coming from so it just makes sense..

Actually, the noise comes from the tires and the road, and moreso, from the vibrational energy that is sent through the the air, to the metal.

The best place you can use your vibration damper is on the side walls of the van.
See, the closer you kill the vibrations to the source, the less vibrations (and noise) will make it to your ears. So whn treating the vibrations you always want to follow the path of the sound from the source, to your ears.

As the wheels spin the send vibrations in nearly 360 degrees. The firs place these vibrations hit your car is the wheel wells. Dampen them first.

The vibratins continue to travel down the length of the vehicle fromthe wheel wells, to the quarter panels in to the doors.
So if you only have a litlle bit of material, do it in this order:

wheel wells
quarterpanels
doors

If you have enough material you can then apply it to the floor and the roof. But a double layer of material on the wheel wells and quarter panles will yield much better results that a single layer will on the floor.

You can also take it a step further and apply a layer of material on the outside of the car. We at Second Skin sell Spectrum, which is an acoustical undercoating. You can app;ly thi to the wheel wells and the floor to sandwich the sheet metal for better vibration damping results.

Keep in mind too, that the product you applied is a vibration damper. Vibrations account for about 50-60% of the noise in a car (structure borne noise), but the remainin noise airborne. To deal with airborne noise you need absorbers and barriers on top of the damper.

Might be confusing but there is no reason y ou can't make that van as quiet as a lexus.

Hope that helps

ANT
www.secondskinaudio.com

[second skin rep]

Aslo, the only thing the bubble wrap stuff from lowes will do is insulate heat.
You should really use a closed cell foam of heavy vinyl barrier on top fo the Damper you have already done.

You might want to consider treating all the bracing as well!

ANT
www.secondskinaudio.com[/url]

[vwlovr]

hey ant,

yeah i know the bubble stuff is only for heat, i'm moving to hawaii so, that's exactly what i want.

i coated all sides and wheel wells and so far i'm happy with results. i figured i'd just get by with the carpet for some absorbing action. i'm not going for Lexus quiet, just not as clangy.

good tips though. i'm going to do some spray on stuff behind the radiator and lights as well as under the center console by the radiator fan. maybe later i'll hit the wheel wells. for now i don't have the time as i'm trying to finish my restoration in time for a road trip. i'm only doing the radiator area b/c i'm dropping in a new radiator.

[82WestyMan]

Hey "Ant / second skin rep"... good to see you here
When I did my Westy, did a lot of research and chose your product over the more popular dynamat product(s)
Just wanted to say how satisfied I am...
Used the Spectrum that I bushed on, lined the interior panels with the adhesive backed butyl mats and then filled the pockets what insulation.
Totally took the flat sheet metal 'tinny-ness' out.
Thanx again and good to see you on TheSamba
_________________
"The floggings will continue until morale improves"
"I never did give anybody hell. I just told the truth and they thought it was hell" - Harry S. Truman
82 Westfalia - w/ a Raby 'Camper Special' engine

[second skin rep]

Awesome!
Glad to hear that you had such positive results!
Let us know if you need anything else!

ANT
www.secondskinaudio.com

[campism]

>You might want to consider treating all the bracing as well!

Regarding the bracing, see what I did on mine:

http://picasaweb.google.com/bike2vcu/Soundproofing02

I figured that if sound could travel through any metal in the body I might as well try to cover as much of it as I could. I still need to do the cab area and inside the front doors, and so still expect further noise reduction.

Stephen

[70coupyel]

Ant,Thanks for that great info. The Second Skin Damplifer is the stuff I used on the doors of my Ghia. Single layer on the inside of the door sheet metal and it make it alot quiter inside. For those of you in L.A..O.C.,and I.E. I went here the score the goods:
http://www.advancedcarcreations.com/main.htm
This place is by The Block in Orange.

Late Glenn
_________________

[Jon_slider]

vw lover said:
> to my ear, it seemed quieter during idle and low rpm cruising. not like amazingly so, but it seemed to take the edge off.

> the test however, didn't show much change.

82WestyMan said:
>Totally took the flat sheet metal 'tinny-ness' out.

DB meters are extremely useful at reporting sound levels..

both vwlover and 82WestyMan THOUGHT the noise had dropped.. wishfull thinking after spending time and money.

When in fact the DB meter reported no change..

now if someone gets their Van as quiet as a Lexus (what DB is that?).. I would like to know about it

As it is I have to shout to be heard by my passenger on the freeway in my syncro westy with subie 2.2

of course Im also guilty of not owning a DB meter .. its just plain LOUD in my van. MUCH louder than with a waterboxer.

J

[vwlovr]

[brooklynvanagon]

More important than a single number db is the spectrum of the sound... our ears/brain are particularly excited by the 2k -8k range... if all the sound level reduction occurs only in this band, then the meter could barely budge .5 db but the percieved difference could be night and day.

http://audio.rightmark.org/index_new.shtml and a laptop and a mic would have been a better way to go for measurements.

[mellow cat]

again, kudos on the info...much thanks....

My feeling, in terms of road noise is not so much the "road" noise or tire noise but the wind noise at 65mph+ My assumption is the air is being "ripped" around the leading A-pillar rain gutter as well as this same edge of the van.?

I wonder if anyone would remember..... in the 80's if you were "tuning" Rabbits and Jetta I you might remember a company that made air foils for these leading edge rain gutters. Looked kewl, I never got a set. anyone? anyone? Bueller?

I think this kind of mod might be worth investigating.?

a bit off subject....fishing for info...

MC

[westylife]

campism,

How much did you buy (second skin seems cheaper)? the pics look great. about how much will I need to do what you did?

Thanks.
_________________
1983.5 Westfalia Bostig RG1

[campism]

westylife,
I bought three 50'x12" rolls of the Extreme and used about 2.5, maybe a little more. I did one layer on everything behind the front seats and up to the windows, with an additional layer on the driver's side wall, the sliding door panel (not the bracing, only one layer there) and in the flutes on the floor.

If I ever get around to it I will do inside the front doors, the front floor, firewall and seat pedestals (everything under carpet) and above the headliner. Right now there is no sound deadener in the front compartment. I figure this will use up what I have left and one more roll, maybe two if I go with extra layers. I might just buy a generic product to finish up with if the price/shipping$/time on getting it is significantly less than the Canadian stuff. And don't forget the exchange rate these days.

[vanaru]

thanks for all who contributed...will save me and others considerable experimentation time and Cash.

[dobryan]

Scott,

I used a bunch of this stuff on my '87 Westy. Come on over for a test drive some time.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

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