Contour Enthusiasts Group Archives Forums Modifications Audio trunk rattle

when u cover the trunk lid and open it, the dynamat is visible, right? do they offer it in solid colors without their logos on it.

You can put dynomat on the lid then put carpet over it if you dont like the look of the dyno.

I found a very reasonable solution that fit my needs. I have one 10" and my trunk was rattling (without license plate noise). I went to "Wally World" (aka walmart) and picked up a couple of bags of "polyester fiberfil" in the arts and craft section for about 2 - 3 bucks. I stuffed every major hole I could find, around the lock mehanism and behind the trunk liner.
A considerable decrease in trunk rattle for under $10 (depends on how thorough you are), cant beat that!
If your gonna try it, dont do a half a$$ job and complain. Its a cheap enough alternative that deserves a decent try.

The polyester fiberfill (aka polyfill) is a good idea in more ways than one.
First, it slows down the sound waves from the speakers, causing the rattle to dissipate some.
Second, when it slows down the sound wave it draws out the wave, so it slightly changes the frequency of the note, so it actually lowers the note being played by the speaker making the bass slightly lower.
I would suggest a combination of polyfill, dynamat and carpet.
This will eliminate 90+% of all rattle.

Sleeper,

The slowing down of the backwave by the fiberfill doesn't make it play deeper. In a midrange enclosure, the slowing down minimizes standing waves that can adversely affect freq response. The standing wave issue isn't really relavent in a subwoofer enclosure because any possible standing waves would be well out of the subs playing range. Which brings us to the use of fiberfill in a sub enclosure.

Normally, when a subwoofer plays for any significant amount of time, the VC and motor get pretty hot. The heat is dissipated through the frame and motor assembly into the enclosure. This heat causes the air to expand and increase the pressure in the enclosure making the sub think that the enclosure is smaller than it is which results in a higher Qtc (boomier bass) and less low end freq extension. When fiberfill is added, the tiny fiber vibrate and actually keep the air in the enclosure cooler. The cooler air, keeps the qtc lower which gives you a slightly more effecient system that will have a small advantage in low bass extension.

I agree with what you said in full, but I though the suggestion was to place the polyfill in the trunk, not the sub enclusure.
If so, the polyester slows the reverberating sound wave and slows it, slightly.
So while it DOES NOT actually change the frequency, we HEAR it as a different rate than what it truly is.

Welcome to the world of FORD!!!! your going to be chasing rattles for as long as you own your system. as soon as you fix one, another will begin. The only way you are truely going to fix it is with expanding foam.