Cutting noise in cabin?

[ecomodded]

Replace the wheel bearings.. Speculation at its finest.

[mcrews]

Not the bearings in my case.
We had it in the shop twice under warrantee.
It's been the same noise level for 145k miles.
Just poor insulation..

[Superfuelgero]

Originally Posted by mcrews

Not the bearings in my case.
We had it in the shop twice under warrantee.
It's been the same noise level for 145k miles.
Just poor insulation..

There are 2 questions to ask when it comes to noise: What is the noise (tire, wind, etc), and where is coming through at (floor, doors, window, etc). Without this, its just a shot in the dark.

[Goldenstate]

First car was a 1968 Camaro with tons of road noise. I rode in a Lincoln with the boss a few times and realized what a quiet car could be. Back then, economy was not the goal, but the quiet ride of the Lincoln was. With a trunk for an echo chamber, I went after it first by caulking all cracks that might let noise into the passenger compartment. A sheet of heavy cardboard with fabric covering was placed behind the seat. The rear deck below the window got some thin black carpet. The trunk floor was custom fitted with a piece of carpet remnant found at a garage sale. I almost put some hood padding from a wrecked car on the underside of the trunk lid but liked the results so well that that option was never completed.

The transmission shifter hole in the floor is a great offender of transmitting noise into the body. I removed the center console and covered up the way too big opening with a few layers of carpet left over from the custom fitting in the trunk. With the console replaced, the noise from the transmission was much reduced.

The interior trim panels from the door to the back seat were removed and no deadening at all was found. I used some left over fiberglass house insulation in those areas.

The rear seats had very little hair pad under them to reduce noise. I put two layers of the left over carpet from the trunk under the seats.

Even with glass pack mufflers on the 327 engine, the interior noise levels were much reduced and my friends wondered why their Camaro bodies were so much nosier than mine.

There was still quite a bit of engine noise from the engine which ran at 3000 RPM at 70 MPH. No wonder it never did get good mileage. I had considered a hood pad kit for under the hood but never did install that option. I had achieved a quiet ride almost equal to the Lincoln for almost zero expense and a few hours of work. It was always a pleasure to be able to enjoy the quiet ride of the Lincoln for much less expense.

[Vman455]

Originally Posted by Xist

What about sound insulation for my bedroom? My roommates frequently have a girl visits who screams for no good reason. They also like playing video games and movies at unholy volumes at uncivilized hours.

The only way to block sound effectively is with mass--doesn't really matter what (mass-loaded vinyl, lead sheet, heavy foam) as long as it is massive. I build organs in my day job, and we use 3/4" MDF sealed with polyclear to make swell boxes (enclosed spaces with shutters on the front that can be opened or closed to control volume); the panels are very heavy, but have to be to be effective.

[NoD~]

There are two ways to deal with noise: You either absorb it or you isolate it. (or both)

Isolation is by far superior, but with higher complexity and/or cost. Basically, you have to have a "2 leaf" system. You currently have a single leaf: The sheetmetal body itself! In order to get a 2nd leaf, you would have to apply a soft layer of material, followed by another layer with much higher mass. Most people use a light foam, covered by a vinyl mass layer. This will drop noise SIGNIFICANTLY! But you have to have complete isolation between the two layers. A recording studio, for example, will have a full solid wall to studs, air space, then to another set of studs with a 2nd full solid wall. Usually fiberglass insulation on each set of the studs, too. I have this in my studio and it can be over 120db inside of live music, with nothing over a whisper on the outside of the building.

Absorption, through use of materials like fiberglass and foam, will take noise and transfer it to heat. This works pretty well in most cases, but usually only takes away high frequency noise. It's cheap and easy to apply. Just put some padding under your carpet! Very simple... but again, not nearly as effective as isolation.

There are products like sound dampeners (dynomat) that help... it basically reduces resonance of your metal and adds a bit off mass to the sheet metal. This can help, but can also get expensive and won't be nearly as effective as isolation.

Can't stress enough: isolation. It makes a HUGE difference (when done right, of course). Though, you can make a pretty quiet ride by doing all the above. Just expect the weight of your wallet to go down and the weight of your car to go up quite a bit more.

As noted above, mass makes the difference. The more mass you put on, the less sound gets through. In a 2-leaf system, the more mass each leaf has, the more effective it will be. But do note: 1 beefy leaf won't beat a basic 2-leaf system. But 2 beefy leafs will dominate all!

As for myself: I used minimal sound dampening (the 1/4 center-coverage method) and did a layer of double-bubble foil wrap insulation under the carpet and attached EVERYWHERE possible on the car (firewall is very well covered), then just standard carpet w/o any foam or anything like that. This isn't extremely "noiseproof" but for the cost and the weight, was effective enough for me.

[Xist]

Okay so:

1. Remove everything from my room.
2. Remove the drywall from my common wall.
3. Punch the noisy roommates and visitors in the throat.
4. Put a layer of bricks between the studs and around the noise makers, like in "The Cask of Amontillado."
5. Replace the drywall and paint.
6. Enjoy the silence!

[redneck]

H-Man

Cutting noise in cabin?
I'm not sure what to do to reduce tire noise in my car, a 1994 Geo Prizm. Any ideas? I can't afford to replace the tires.

Ear plugs.

>

[mcrews]

Originally Posted by Xist

Okay so:

1. Remove everything from my room.
2. Remove the drywall from my common wall.
3. Punch the noisy roommates and visitors in the throat.
4. Put a layer of bricks between the studs and around the noise makers, like in "The Cask of Amontillado."
5. Replace the drywall and paint.
6. Enjoy the silence!

You have obviously given this some thought....!!!

[ecomodded]

Maybe you could sell the car to Deaf person / senior and cut your losses.

Advertise it as Perfect for a Senior and keep it parked out front of the Deaf school, find that car a happy new owner !