Sound insulation

[Turbobrick]

MyFocus has brought up a good point about sound insulation with acoustic engineering, what is that all about?

 

MyFocus, your turn

[Myfocus]

I know I shouldn't touch this even with a 100foot pole!

 

I'm no accostic engr, and there are a lot more knowledable ICE guys here, so I'll just throw in my $0.02.

 

There are many aims of accoustic engrg, which are to advance the aims of marketing. For example, if you want to project an image of a solid car, you engineer it so that the fit and reonance chambers (eg body panel space & mass) will produce sound in the correct frequency range. Of course you have to ensure good tight fit, even closing of doors and even the angle which it closes.

 

On the other hand, you may want to project an image of a really, really upmarket car so quiet you think you are in your amchair or a recording studio. Apart from NVH, you have to see how you do noise isolation (door seals, damping which is related to mass and frequency ranges etc.

 

The problem of damping is what works for one frequency range may not work for another, and the solution may conflict with some other design requirement (eg reduce weight or increase fuel economy).

 

But the advantage is you can get the end result for a lot less $$$ than your competitors - you dun spend on heavy structural parts but still get that impression of solid build.

 

Or you may want to benchmark your competitors and build a car with all the best features from your competitors eg nice exhaust note. So you tune the exhaust accordingly. There's a very popular car which did this some years back, no names mentioned :-)

 

Over to the real tech guys now :-)

 

MyFocus has brought up a good point about sound insulation with acoustic engineering, what is that all about?

 

MyFocus, your turn

[Madarmour]

Thanks, your posting is very educational!

 

NVH - Noise, vibration, h.......... Can enlighten me whet the 'h' stands for?

 

Cheers!

[Turbobrick]

H=harmonics?

[Barakian]

I think its harshness....

[Myfocus]

...and the winner is

Barakian!

 

Yup, harshness. Think lexus advert of violin recording in the car.....

 

I think its harshness....

[Turbobrick]

Oh Harshness!

 

Well, my car has solid NVH! Machiam like MRT ride everyday

[Barakian]

Oh thank you, thank you! I would also like to thank my mother, my father, my 2nd uncle's 3rd daughter's 52nd cousin's 12th niece, all my friends, His Holiness The Pope, the King of Norway, and other distinguished guests..... [;)][;)][;)][;)]

[Ghostrider]

Depending on certain cars.....H happens to stands for HARD !!! Bwahahahahahahha

 

[Barakian]

Dun tell me you trying to target a certain silver Skoda again??!!

[Turbobrick]

I've come across two types of insulation material, one is absorbsion type and the other is damping type.....anyone can enlighten me on the characteristics and purpose of using either one or in combination???

[Ghostrider]

Damping material actually is used to cut down on the vibration/drumming of the body panels. It is used on big panels of unsupported panels.

 

Damping sheets are usually used on door panels.

 

Absorbing sheets are usually used on the floor area to absorb the road noise. They usually contain dual or triple layers of materials. Fire retardant felt and bitumen are usually used.

 

For those who seek a tighter bass when using free air subs, the boot is a good place to do up your sound proofing. It will add in making the enclosure tighter and hence the sound is more punchy. But dun expect performance like a box up woofer system.

[Turbobrick]

So the damping material is used to curb vibrations from the inside or outside of the panel?

 

Are the absorbing materials used on the inside of wheel wells too?

[Ghostrider]

Off course inside lah !! Where got pple stick on the outside one ???

 

Wheel arch uses the absorbant type of sound proofing material. But some KS pple uses both type !! Defintely have effect one !!

[Turbobrick]

Aiyah what I was asking is the panel insulation is to prevent the inside sound from vibin out or prevent outside sounds from coming in???

[Ghostrider]

To prevent the panel from vibrating....hence no sound at all.....inside out or outside in....no factors.

[Turbobrick]

I'm trying to help my friend insulate his Sunny door panels with insuflex thin (6mm) foam, but the window winds down between the door panel and inner metal frame. How does the sound guys insulate such a tight spot?

[Cool]

Turbobrick.

 

There is a special thin bar for panel Beating which they used to push the insulator into this area (After it is cut)