David Hayes

iTrader: (6)

Absolutely. The stuff works very well and has held up to over 4 years now. It's easy to apply and is 3X as effective as Dynamat so there is very little not to like.

As an interesting note, most guys that hear my doors close (thud versus the usual tinny sound) ask how is that possible?

DMoneyRX-7

iTrader: (2)

nice. Looks like that's what I'm gonna go with then. I don't think I'm going to use spray or anything. I'll just use a paintbrush for it all and get some helping hands. Should make it easier.

David Hayes

iTrader: (6)

If you have an air compressor, spraying is very easy. You can buy everything you need from Quiet Coat except the compressor.

If you paint it on, then you apply each coat thickly, like a bad paint job. Three coats will do it and it is easy either way.

DMoneyRX-7

iTrader: (2)

I would like to spray it because of the ease and quickness of the process. But I know with my luck I would mess something up and have overspray

David Hayes

iTrader: (6)

If you have the interior removed, it's the way to go. Just paper and tape off the areas you don't want to overspray. It's a thicker product than paint so that does minimize a bit overspray. If not, painting it on works but takes longer.

ourxseven

iTrader: (1)

Can the quiet coat be sprayed over POR 15 ?

my first gen is strippedfor painting and the previous owner put POR15 in the trunk area and the entire floor .

bc_fd3s

iTrader: (2)

So I am in the process of coating my underbody with rubberized undercoat. Do you think this would make a difference if I coated first with the Quiet Car and then the undercoat over top of that?

David Hayes

iTrader: (6)

Have no idea what POR15 is but Quiet Coat needs to be applied directly to the metal for it to work.

David Hayes

iTrader: (6)

Yes, it would make a huge difference. Put on 3 coats of Quiet Coat and then apply the undercoat and you'd be good to go. You might not even need the undercoat but you could ask the Quiet Coat guys this.

spyfish007

So in case any one wanted this REALLY old write-up, I put it on my new domain. Not sure it really helped anyone, but maybe someone will like it.

RX-7 sound dampening

satch

iTrader: (1)

Kind of hard to tell but did you do the outer skin of the door as well?

David Hayes

iTrader: (6)

Go with Quiet Coat - it i easier to apply, costs less, it weighs less, and it works about 3X better than the stick on stuff. Pretty much a no brainer if you ask me.

Here is a new thread with some pics:

https://www.rx7club.com/interior-exterior-audio-26/fd-interior-remodling-project-885635/

spyfish007

I used an old version of that stuff about 15 years ago. Didn't like it then, but the stuff you are using looks much better.

boostd4

iTrader: (4)

I'm about to start the dampenning project on my FD.

FWIW, if you're looking for cabin noise reduction, spray on crap or mats aren't going to do much at all. Those are for VIBRATION reduction. They will make your audio tighter and cripser as less engery is lost through metal panels and is worth while to do, but it is DEFINITELY not necessary to do every squre inch.

I did this to my tin can 2000 Civic that came from the factory with almost ZERO deadening. First I covered the ENTIRE inside in Raamat (same as Dynamat Extreme and others). I sprayed ruberrized undercoating into every nook and cranny that I couldn't get with mat (similar to doing the B-quiet spray/paint on). There was almost no difference in cabin noise. maybe 1-2 decibels or so, but the subwoofer sounded AMAZING. Super tight bass with no rattles.

The biggest effect on cabin NOISE was stuffing the body panels full of foam. I actually used carpet padding on the Civic, but I wouldn't do that again because you have to be very careful about places that see moisture as carpet padding will suck it up and smell like mildew. In those places you can use closed cell foam. Anyway I had a big roll of carpet padding (like $25 or so), and cut it up in to 6"x6" squares. I took the speakers out of the rear panels (in the Civic... in an FD, you'd take the access panels off) and just stuffed the panel FULL of these little squares. Yea, they were loose and would fall out if you removed the panle, but that's why I cut 6"x6" squares... easy to clean up/refill the panel if I had to remove it.

I did this with every panel in the rear and it was NIGHT AND DAY. I had blown trailing arm bushings that clunked like someone hitting a ball-peen hammer on the bottom of the car before hand. After the mat/spray it changed the pitch of the clunk but was still just as audible. After the carpet padding THE SOUND WAS COMPLETELY GONE. I understand they needed to be changed, but that demonstrates how well that form of audio dampenning works.

I plan to use VLC tiles (? the thick dampenning tiles) for vibration on the middle of panels, and a coat of some paint on dampenner for the odd shaped areas. After that, I'll cover EVERYTHING in closed cell foam (makes mating surfaces quieter for body panels, etc), then I'll stuff all the panels I can with egg-crate like accoustic foam. I'll post back when it's done.

I have the RATTLIEST FD I've ever been in. It needs new pillow *****, diff mounts, and toe/trailing bushings. I'm going to do the deadening first to see how well it dampens those noises before I change all those parts.

David Hayes

iTrader: (6)

Sorry, but not true for products like Quiet Car, a spray on product. Quiet Car DOES reduce noise at a rate about 2X better than any other product out there, including mat products. Your statement is true about rubberized undercoatings but that is not what Quiet Car is, it's a product that bonds with the metal and results in superior noise reduction which BTW is vibration control. Sound/noise is the passing of vibration thru metal and if you eliminate this, then you will eliminate sound. See here for more on Quiet Car:

http://quietcoat.com/

I used this on my FD and reduced sound by over 15 dbs, which is a huge gain. You can now get in my car and carry on a conversation. See my link above for the proof.

And the thought of all that combustable material (foam) shoved into my car doesn't give me a good warm feeling especially when a better methodology exists.

boostd4

iTrader: (4)

I respect that you took the time to take measurements and document your process, but the "my *opinion* is the only right opinion" attitude is starting to get a little old. Spamming every thread where someone has had success with a different method, or discounting their efferts is well... just not so classy.

I'm not sure you understand how different deadenning agents work. I won't disagree with you that Quiet Car performs better against other products designed to do the same thing (like other paint-on deadeners, and roll on mats). Quiet Car is NOT a decoupling agent, nor does it play a big part in multiple barrier sound resisitance.

You might want to give this site a read if you haven't:

http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

My experience wasn't made up, and I won't discredit Quiet Car. I work for BMW and take those cars apart every day. BMW (like other super-quiet luxury cars) uses mats on the floors and certain areas. Almost every panel is lined with either a carpet padding like material, or CLOSED CELL FOAM. My Lexus is the same way and both cars are dead quiet.

Sure, a product like Quiet Car is an excellent addition to a sound deadenning plan. I will use it when I re-do my lexus (in addition to VLC tiles, and foam). But to say you don't need anything else because it does the job of those other things better... well.. is just plain wrong.

David Hayes

iTrader: (6)

The Easter Bunny wasn't good to someone was he? I never said my "opinion" was correct, just that your statement of "fact" wasn't. You stated:

"FWIW, if you're looking for cabin noise reduction, spray on crap or mats aren't going to do much at all."

That is just not true and that is what I responded to. It is factually false and I felt others needed to know. I am not familiar with other spray ons, but I am very familiar with Quiet Coat and I took extensive time to learn about the product and to test and verify my results and I can state as "fact" the product does indeed reduce cabin noise in RX7s by over 15 decibels and this is a huge decrease in cabin sound by any measurement. For what that translates to:

http://www.800nonoise.com/tutorial_4ways.htm

"A 5 decibel noise reduction represents a reduction of 50% of the acoustical energy produced by the noise source. OSHA also states that a 5 db noise reduction represents a 50% decrease in the risk of hearing loss. (Noises reduced by 5 decibels sound about 30% quieter.) A 10 decibel reduction represents a 90% decrease in acoustical energy and sounds half as loud."

So, a 5 db noise reduction is 50% LESS sound and I achieved a 15 db reduction which is crazy good. Frankly I didn't know much about sound reduction until I did this project and sound engineers on the forum were very impressed. They even had me test both dba and dbc levels with equal results. So if I have reduced overall cabin sound by 15 decibels, why do anything else?

And I did read thru your referenced website and I would say the reason I got such good results is that the product I used does 2 of the 3 things listed well, it stops vibration and it also absorbs the sound. From the Quiet Coat website:

"The advanced viscoelastic properties allow the coating to actually absorb unwanted noise and vibration, rather than just block it (which is what mats do)."

So, if the product DOES stop sound and I can achieve a 15 dba reduction in cabin noise AND the product weighs significantly less than any other product (mats and your approach) why would I do something else? I guess if I had a vibration problem somewhere that I didn't coat I might shove some closed cell stuff in there but the goal of most on the forum is superior sound deadening AND weight reduction and I'll put up my method to yours any day on achieving superior reductions. You might be surprised to learn that in Europe Quiet Car is used extensively with the luxury brands like BMW and Range Rover to meet the stricter European sound dampening requirements.

An yes, I too have seen what is done on luxury cars like my Range Rover. I actually commented on this about a month ago when pulling apart the back section of the Range Rover where they used carpet padding. Of course this was on plastic where a product like Quiet Car wouldn't work.

Finally, I am not a "spammer" and your statement is uncalled for:

"Spamming every thread where someone has had success with a different method, or discounting their efferts is well... just not so classy."

It's okay to disagree but not okay to be loose with the facts and this is the only reason I responded because your statement was incorrect. The goal of this thread is to present the best sound dampening techniques to the community so we are all better educated. Good luck with your project and take some before and after measurements and post them up.

boostd4

iTrader: (4)

There is always an exception to the rule. If you ask ANYONE in the car audio business if it's possible to get a 15db noise decrease by sound deadening a stock vehicle, they will laugh.... hard. Of course if you're counting a retardedly loud exhaust as part of your "stock" sound levels, than the results are horribly skewed.

I applaud your efforts. I read your thread (and forgot I posted nearly the same thing in it a while ago), and I doubt 99% of people are willing to make a year long project out of it like you did. You obviously went above and beyond what the average guy would do, and that's awesome.

But to state the exception to the rule... as the rule.. is misleading. My experience (from deadening a few cars, and from personal experience of friends/club members over the last 10+ years), is of what I stated..

..and.. apparently is shared by someone who tried your approach, and mine, on the same car: (from your thread)

David Hayes

iTrader: (6)

So how many of us on this forum have a stock vehicle? Of course my car is highly modified (search for my name and my 3 rotor conversion) and yes, it does include a very loud exhaust system, like 99% of the cars on this forum. If my car was stock I don't know that I would ever have bothered with sound proofing at all. So I think what I have done applies to the vast majority of cars on this forum and as such is worthwhile as a consideration for those that want a quiet car (no pun intended).

And the project didn't take a year, it took two weekends to do. I am sure the thread went on for a year as it was pretty popular back then which was like 5 years ago. And the car still sounds great. Outside of the obvious that I have already posted, my RX7 owners are surprised when they shut my doors and the close with a "thud" versus the normal tinny sound. And FYI - I haven't read thru the thread you posted but if he didn't do the doors then he made a serious mistake as that is where I got the most bang for the buck in sound reduction.

But to each his own. I doubt my results will sway the guys that swear buy the mat products or will change your plans. Use what you like and move on - life is too short.

boostd4

iTrader: (4)

?? I took that quote from a post in YOUR Quiet Coat thread.... I assume you are subscribed to it...

Anyway, you are right that some people are just set in their ways and won't change their mind about certain products. The only reason I'm sticking to mine is because I've tried both and have experienced both kinds. I don't want it to come off like I read a few threads on the internet and am spewing regurgitated garbage.

David Hayes

iTrader: (6)

I haven't visited the thread in quite some time so maybe I should go check it out. How about posting up some pics and takes some before and after pics? You can buy a good decibel meter for about $35 at Radio Shack.

muibubbles

iTrader: (36)

hey has anybody tried the quiet coat beside in the interior? my whole cabin is quiet coated but im thinking about using the rest on the back of the fenders/bumper to reduce engine noise... the HBP is a little rumbler =)

David Hayes

iTrader: (6)

I used it on the inside of the engine hood, in the trunk and under the car with some success. I would think if you removed the plastic liners from the fenders and sprayed in there, you'd get some good results. I bet it would eliminate a good amount of tire noise.

muibubbles

iTrader: (36)

awesome, once the engine rest back on the subframe im going to tackle this.... butttt id just take the fenders off

i wanna do the hood as well but i dont have a liner on it and the texture of quietcoat will look like pootie =(

TwinCharged RX7

iTrader: (14)

I bet if you spray it on it would look pretty decent. You can even paint it Hot Pink after

And I'm only half joking, haha, because of your white vented hood you might get a pretty cool affect. Kind of like snowboards with the red bottom. Makes the snow look cool.