Sound dampening

[brucepelletier]

What are other members' experience with various sound dampening materials and installation?

After removing door panels, rear package shelf, rear trunk panel and both rear seat cushions to take out the Bose speakers for refurbishing I'm wondering about the best way to add some sound dampening to my 90 Q when everything goes back together.

Driving around with no sound system has given me a chance to really listen to the interior noise levels. I'm willing to trade off a little extra weight for less noise. To me, the Q has plenty of power to spare to take the added pounds anyway.

I've even speculated about replacing the side window glass with the thicker 94-96 glass but wonder if it would fit or be a good color match.

What's under the floor carpet and how hard would it be to add some sound dampening there? The firewall? Wheel wells? (I'm noticing tire noise more than anything else). Your experiences, please.

[DAEDALUS]

I'm curious too, but I would hesitate to do anything for a stock Bose system. The stereo system was custom tuned by Bose for the interior of the Q. Add sound matting and you change the equation. I'm skeptical with stock, but I do think it would be a good thing to do with an aftermarket system that is more tuneable than the stock system.

[tkd_q45]

I'd try starting with the rear door panels. They sound (upon thumping them) as if they have NO damping materials on them. I'd put multiple layers in there. You might also checking out the trunk area/rear quarter panels as well as the trunk lid. Every bit helps. Anywhere you thump your car (exterior panels) an you hear a "ring" instead of a "thud", is a place that could use noise damping. I too would like to quiet things down a bit but job, wife and daughter conspire against me! Though Daedalus is right about the Bose's Q45 specific tuning, I'd think that added "stabalization" of noise could only help. Many audiophile types add things like Dynamat to better improve system performance.

[juiceman]

Be sure to do it correctly as water does flow thru a door when it rains. You do not want to trap water in there and make an environment that produces rust.

[Mayhem_J30]

Be sure to do it correctly as water does flow thru a door when it rains. You do not want to trap water in there and make an environment that produces rust.

true. so you could put the dampening material on the outside of the plastic cover, the one that's in contact with the actual door panel. That protection should be sufficient.

[maxnix]

Quote »so you could put the dampening material on the outside of the plastic cover, the one that's in contact with the actual door panel.[/quote] Actually, if you look at other cars or 1994-1996 Qs, you will see the mass attached to the door skin to reduce the harmonic frequency of the panel. Such bonding to sheet metal should have little effect on the reflective acoustic environment, for which the audio system is not tuned that well, except to diminish low frequency resonance levels.

[diamondj30]

what is your goal.mcmaster-carr online ,they have visiolastic and high temp mastic.it is very cheap compared to dynamat and cascade VB-2 and is exactly the same with out the silkscreen name on it.you will need a heat gun,go to home depot they have insulating rubatex rolls.

[brucepelletier]

what is your goal.mcmaster-carr online ,they have visiolastic and high temp mastic.it is very cheap compared to dynamat and cascade VB-2 and is exactly the same with out the silkscreen name on it.you will need a heat gun,go to home depot they have insulating rubatex rolls.

I'm trying for maximum sound dampening to lower road noise. I'm restoring the factory Bose system speakers and this system really is good enough for my ears. This is only indirectly about improving the performance of the sound system and more about getting a really quiet car.

Your post is along the lines I was hoping to elicit. I'm curious about other members' experiences with the various materials on the market. In doing a brief Google search I came up with Dynamat, Accumat, Cascade, and serveral others in all kinds of forms and variations.

I'm also willing to pay a little more for ease of installation. If I can avoid having to use a heat gun I'd rather not have to use one if another, easier to install material is as good or better.

Thanks for your response.

[Q451990]

You might check to see if your car ever had the anti-windnoise measures installed. This included different front door windows and rub rails, and adding extra sealant to the front windshield, and a thicker foam block behind the mirrors. There was a TSB on this back in October of 1990 (ITB90-003A). For road noise I'd say you're on track with the dynamat or maybe a spray on deadening material. How about undercoating inside the door panels?

I'd wait until you get your Bose back online before you do too much. With no tunes every single little noise bugs the heck out of me...

Heath

[Sopdadope]

In my experience, nothing beats sheets of Brown Bread. I ordered it online somewhere. You can buy it by the yard and it's relatively inexpensive compared to dynamat, Road Kill spray insulator.

Removing the door panels are easy, but the carpet is a whole other story. To properly remove the carpet, you'll have to take out all seats. There is some insulation there already, but you can never have enough sound deadening.

For the wheel wheels, use rubber undercoating sprays, it works great. My car's the quietest Q around and I know this for a fact (80 lbs. worth of Brown Bread and dynamat in the doors) but things can get pretty wild when I crank up the stereo!

[natsoundup]

What type of rubber undercoating do you use... I would say rear well road noise is about my only complaint....

[Sopdadope]

3M...but any brand should do the job.

[greg_atlanta]

Is there any benefit to adding insulation between the trunk and the back seat? Lots of dead space around gas tank, easy to access compared to door panels.

[brucepelletier]

Go, guys! This is the kind of specific info I need.

[brucepelletier]

In my experience, nothing beats sheets of Brown Bread. I ordered it online somewhere. You can buy it by the yard and it's relatively inexpensive compared to dynamat, Road Kill spray insulator.

Removing the door panels are easy, but the carpet is a whole other story. To properly remove the carpet, you'll have to take out all seats. There is some insulation there already, but you can never have enough sound deadening.

For the wheel wheels, use rubber undercoating sprays, it works great. My car's the quietest Q around and I know this for a fact (80 lbs. worth of Brown Bread and dynamat in the doors) but things can get pretty wild when I crank up the stereo!

Great info! Could you elaborate a bit on your points?

Brown Bread - what is installation like? Is there more than one form? Can it be used all around - doors, floors, etc.? Does it smell funny, especially in hot weather?

What is Road Kill?

If you've removed your carpet, what did you find as the original insulation and what did you add? Is removing the front seats more involved than just unbolting, disconnecting power leads and lifting out? What about the door sills - these must have to be removed, too? Did you remove EVERYTHING in the front - seats, center console, door sills?

How do you apply undercoating to the wheel wells? Do you remove the plastic liners and spay it on the back then reinstall, or do you just spay it on the 'weather' side?

More questions but I'll stop here. Many thanks for your response.

[brucepelletier]

Is there any benefit to adding insulation between the trunk and the back seat? Lots of dead space around gas tank, easy to access compared to door panels.

Good question. I was thinking about the same thing.

And the rear package shelf. Not much sound dampening material at all when I removed the speakers. This looks like prime territory for treatment.

[Q451990]

I thought about the area around the gas tank too, but with the Bose system relying on tuning so much, I'd probably avoid it. I doubt door panels would matter much since the box is ported to the front.

Heath

[Sopdadope]

Is there any benefit to adding insulation between the trunk and the back seat? Lots of dead space around gas tank, easy to access compared to door panels.

I didn't add any insulation there. I have a sub in my car so there's no point in trying to dampen the rear deck.

The biggest difference was the rolling the Brown Bread onto the floorpan.

[Sopdadope]

As I said before, the biggest difference was the deadening on the floor pan AND the wheel wells. Personally, dampening the doors isn't worthwhile UNLESS you're installing a high-wattage, aftermarket stereo system.

First thing you should tackle are the wheel wells. I didn't remove the plastic, just removed the wheels and sprayed liberal amounts of rubberized undercoating spray (apprx. 1/8th of an inch thick). Combined with quiet, quality tires the cabin will become a much more serene environment on long road trips.

[csoluri92Q]

I recently lined all the door skins with a nice layer of Dynamat in my 92Q. The factory had installed a small patch around the door handle area only. It certainly made a nice improvement in reducing road noise, not to mention the nice "thunk" the doors now make when they are closed. they used to make a loose vibrating noise when closed. Spraying the wheel wells sounds like a great idea as I would like to further reduce highway road noise.

One thing I noticed in 3 of the doors was the factory "glue" used to attach the door skins to the center door frame had come loose, likely causing much of the door skin vibration. A glue gun was used to reattach the door skins, along with lining the door skin above and below the center frame with Dynamat, and finally putting a piece of Dynamat along the center frame. The result is a very solid and quiet door.

Chris

[Q451990]

One thing I noticed in 3 of the doors was the factory "glue" used to attach the door skins to the center door frame had come loose, likely causing much of the door skin vibration. Chris

I'm not sure what they used for that glue, but I think it's designed so that you can pull the plastic skin back to service the power windows regulators, door locks, etc.

The material they used reminds me of dried out plumbers putty, so I scraped as much of it off as possible and used new plumbers putty... seems to work great and you can still pull the plastic back if you need to! That may work with the glue gun glue too - never worked with hot glue guns...

Heath

[csoluri92Q]

Heath,

The glue I was referencing are extremely brittle blobs (after 10 years anyway) used to hold the outside door skin (the painted sheet metal) to the center door beam which runs horizontally down the middle of the door. i suspect the door beam provides the structural strength in the case of an accident. The plastic sheeting under the door panel does use a very sticky black putty. I was able to pull it off with the plastic and simply reattach the plastic when I was finished. I hope this helps!!

[natsoundup]

Boy, have I been ignorant.... I am going to order this stuff for both the Q and the Expedition.... a place on the internet has 36 sq feet for 140 dollars for the Dynamat Extreme..

Anyone try B-Quiet Extreme...it seems like a generic.

[diamondj30]

my car is super quite unlike regular j30s.that was reason i did it in the first place to quite the car down.i can barely hear my own air horns,but i can tell others do.

[AGM]

I can't remember what brand of sound dampening I used as it was done by my motor trimmer. The material was similar to the sheet you put over you when you have an Xray. It feels like a peice of material made out of lead.

The trimmer affixed the material directly to the door trims, so it is actually part of the door trim, not part of the door. Did the rear parcel shelf right up to the underside of the carpet to the driver seat. The material used in the doors was not as heavy a gauge as the rear parcel shelf area, as ther is less room in the door panels to affix the material.

There is an improvement, but not as much as I expected.

Another option is 'noisekiller' made by rocksford fosgate. It comes in two options of cans, one for painting on with an spray gun and the other in an aerosol can you can spray on yourself.

I would go for the aerosol can if you do not have the correct spray gun and nozel.

Regards

AGM

[Q451990]

Heath,

The glue I was referencing are extremely brittle blobs (after 10 years anyway) used to hold the outside door skin (the painted sheet metal) to the center door beam which runs horizontally down the middle of the door. i suspect the door beam provides the structural strength in the case of an accident. The plastic sheeting under the door panel does use a very sticky black putty. I was able to pull it off with the plastic and simply reattach the plastic when I was finished. I hope this helps!!

Wow... completely crossed the wires on that one! I never even thought to look in there that far! I'm not sure I want to take "Q2" apart again anytime soon, but if I do I'll sure check it out.

The plastic barrier on the 90 is held on with a tan looking stuff... I swear it's plumber's putty... sticks to your shoes like it and everything!

Heath

[brucepelletier]

Boy, have I been ignorant.... I am going to order this stuff for both the Q and the Expedition.... a place on the internet has 36 sq feet for 140 dollars for the Dynamat Extreme..

Anyone try B-Quiet Extreme...it seems like a generic.

That's a great price. What's the url for this website? I found the Dynamat Extreme bulk pack at Fry's( a San Jose, CA, electronics retailer) for $200 + tax or the B-quiet website in Canada $195, no tax and free UPS ground shipping.

[brucepelletier]

I can't remember what brand of sound dampening I used as it was done by my motor trimmer. The material was similar to the sheet you put over you when you have an Xray. It feels like a peice of material made out of lead.

The trimmer affixed the material directly to the door trims, so it is actually part of the door trim, not part of the door. Did the rear parcel shelf right up to the underside of the carpet to the driver seat. The material used in the doors was not as heavy a gauge as the rear parcel shelf area, as ther is less room in the door panels to affix the material.

There is an improvement, but not as much as I expected.

Another option is 'noisekiller' made by rocksford fosgate. It comes in two options of cans, one for painting on with an spray gun and the other in an aerosol can you can spray on yourself.

I would go for the aerosol can if you do not have the correct spray gun and nozel.

Regards

AGM

Is Noisekiller the brand name? Where is it available? Do you think it would be good for the wheel wells? With the Bose speakers out I'm hearing tire noise which is very annoying. Has anyone ever removed the plastic wheel well liners, sprayed sound dampening on the rear and reinstalled them? I can get to the rear wheel well bodywork on the inside through the trunk but can't figure out how to sound proof the fronts. Any experiences?

[Sopdadope]

Is Noisekiller the brand name? Where is it available? Do you think it would be good for the wheel wells? With the Bose speakers out I'm hearing tire noise which is very annoying. Has anyone ever removed the plastic wheel well liners, sprayed sound dampening on the rear and reinstalled them? I can get to the rear wheel well bodywork on the inside through the trunk but can't figure out how to sound proof the fronts. Any experiences?

It's actually called "Road Kill" by Rockford Fosgate. Check with your local Best Buy, Good Guys, Circuit City or other large electronic chain as they usually have some stored away in their installation bays.

I wouldn't recommend using this for the wheel wells, it's very expensive ($40 per gallon here). I've been doing stereo installs since freshman year in HS. Most of the time, I just use materials you could find at Home Depot ie foam insulation, rubberized undercoating, mastic roofing insulator as they can get the job done for less than brand-name dampening like Dynamat. B-Quiet Brown Bread is great. Only downside to it is the odor it releases when heated up. Easy to apply though- just use a hair-dryer to heat it up and paint-roller to roll it on.

[diamondj30]

i only used high temp on trunk floor.smell disapates fast.its not a prob.visciolastic is awsome.its lighter,trunks doors headliner floor so on.i did the outside wheel wells not much effect there.i used thick undercoating.blue trigger bottle.im going to do my 200sx.just to m ake it comfortable and quite.my j is so insulated that when i leave the bar at night other peoples windows are fogged and icy,mine looks like i just pulled up.i only hear fire trucks if ther next to me.i keep a good eye out.