Sound deadening

[dabill]

the inside of my car is stripped (apart from the dash...)

gonna clean the carpets but also, have had a leak at some point so the felt is prety much fubar now.

whats best to clean the floor surface and would it be good to treat it with anything...

how many roles of that stuff would i probbaly need? guessing about 4ish... also guess it adds alot of weight to the car yeah?

might just do the doors and quarter panels and buy some felt for the floor and cut it to shape.
if i do this, can i get ahold of the felt stuff?

cheers,

rob

[vr4000d]

second skin is better than dynamat etc the range can be viewed here

http://www.caraudiodirect.co.uk/index.php?manufacturers_id=106&cadid=c77cf16b9c36e4f3211fd5daef104922

[dubsport]

do you think carpet underlay would drowned out some of the noise? looks the same as the expensive stuff hehe

[Ben Lessani]

The whole point is mass loading. You want make the panels heavier to that they are less likely to resonate

[mk2mark]

Just to clarify, resonation frequencies are not bound to an objects mass - the wood I used in my guitar was mahogany, because it resonates at the right frequencies - hasn't much to do with its weight. I think how you apply that to cars is you stick something to the panels to take their resonating frequency out of the range that a car experiences, not to make them heavier. Granted the heavier something is, generally the lower its resonating frequency, but it's not a hard rule, I could have used oak in my guitar which weighs the same as mahogany but resonates at all the wrong frequencies. No idea what my point is, I'm just being pedantic Maybe there's a dynamat material out there that weighs the same as polystyrene?

[Ben Lessani]

Just to clarify, resonation frequencies are not bound to an objects mass... Maybe there's a dynamat material out there that weighs the same as polystyrene?

About right yeah, but the closest thing you can do to stop the panels resonating is to make them less likely to vibrate, adding mass helps indefinately (needs more force to vibrate etc.) Foil backed dynamat has the principal that it reflects sound waves to keep the music in the vehicle. Heres the basics of sound deadening...

Damper – by far the most common type of material. It uses mass loading to lower panel resonance and absorb structural vibrations, converting them into low level heat. Most commonly used throughout a vehicle to control structural related noises. They can also be used in conjunction with a composite to reduce road/engine/exhaust noise. (Extreme &  Ultimate )

Absorber – as the name suggests, these products literally absorb airborne sound waves. The sound waves have to propagate through the absorber and the open/closed cell foam will slow it’s progress reducing the overall level in the process. Most commonly used on floors and firewalls to reduce road/engine/exhaust noise. (Hliner, Vcomp & Lcomp)

Barrier – as the name suggest, these products form a barrier or wall, which blocks airborne noise from passing through. The denser the barrier, the more effective it is, which makes lead an excellent choice for a barrier. Most commonly used on floors and firewalls to reduce road/engine/exhaust noise. (Vcomp & Lcomp)

Composite – Best results are achieved by using more than one of sound deadening, so a composite is quite simply a combination of two of the above types into a single easy to install product. (Vcomp & Lcomp)

[herbster]

I used matting that gardeners use in greenhouses under the pots for retaining moisture, used a bit of spray glue to hold it in place behind the door cards on the inside panels, quite a few layers under the carpet, makes it fee/look a bit plusher too, one layer under the boot carpet and rear seat.