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View Full Version : Surpassing limitations on sound quality.



Buffalohed
04-13-2007, 04:15 PM
I'm beginning to realize a couple things about achieving SQ in a car.

1. You are ultimately limited by sound proofing and the acoustical properties of your car. I have put tons and tons of time and money into deadening my car and there is still a lot of noise that comes in, from many different sources. Unless I can figure out how to silence it, my car can only sound so good while driving.

2. Rear fill provides a nice "sound experience", for lack of a better term, but it inevitably detracts from sound quality and accuracy. I have found that while I enjoy having sound all around me, and the rear fill adds a lot of depth (largely I think because it bounces off the rear window), there is a significant trade-off for accuracy, tonality, and response curve when you go with rear fill. When I figure out how to raise and widen my soundstage I will be golden, because right now it is pretty low, and there is a lot of interference between my tweeters due to placement.

Every so often I decide on a new mini-deadening project but they continue to yield smaller and smaller reductions in noise. The next thing I am going to do is try to deaden the engine compartment, do something with the firewall, and then apply rubber undercoating to the actual underbody of the car (it's already in the wheel wells). I'm also thinking about getting some studio acoustical foam and sealing off the front footwells with it, meaning it will be under the dash and facing downward, to cut down on standing waves. Hopefully that will help some. There is almost nothing more I can do inside the actual car short of taking off the dash and deadening the inside firewall. The entire interior is double or tripled layered in raamat and ensolite, while the rear doors are completely filled and sealed with great stuff.

As far as my speakers, when I upgrade my components I am going to move my tweeters from their current place in the upper doors and move them to right next to the base of the a-pillars. I think that will really improve my soundstage.

Anyway I just thought I would share those little tidbits with you folks. Sorry I type so much :crap:

Eugenics
04-13-2007, 04:18 PM
congratulations. now you can move onto the 13th insight.

Buffalohed
04-13-2007, 04:20 PM
congratulations. now you can move onto the 13th insight.
And what would that be?

JimJ
04-13-2007, 04:21 PM
Yup, you aren't the first, and won't be the last, to stumble across these things :)

Eugenics
04-13-2007, 04:25 PM
a book

Buffalohed
04-13-2007, 04:26 PM
a book

Which book? I have many.

WhoSayWho?
04-13-2007, 04:28 PM
Which book? I have many.

One with more words than pictures.

Eugenics
04-13-2007, 04:34 PM
One with more words than pictures.

You read him like a book. A children's book. Nothing but pictures and ****.

Buffalohed
04-13-2007, 04:38 PM
One with more words than pictures.
I don't think I have any books with pictures except for ones packed up in boxes.

Eugenics
04-13-2007, 04:41 PM
I don't think I have any books with pictures except for ones packed up in boxes.

I display all of mine in our china cabinet.

Hebrew Hammer
04-13-2007, 04:42 PM
mix up your mediums in damping....I use raamat along with ensolite...your truly need to use both...no less than 2 layers of raamat along with a layer of ensolite on every panel...

now the floor in my car is like this...2 layers of raamat, 2 layers of ensolite, 2 layers of raamat, 2 layers of ensolte, 1 layer of raamat....this is the best you can do short of concreting your floor...

Buffalohed
04-13-2007, 04:43 PM
I display all of mine in our china cabinet.

So were you going to recommend a book or did you plan on leaving me hanging?

Buffalohed
04-13-2007, 04:46 PM
mix up your mediums in damping....I use raamat along with ensolite...your truly need to use both...no less than 2 layers of raamat along with a layer of ensolite on every panel...

now the floor in my car is like this...2 layers of raamat, 2 layers of ensolite, 2 layers of raamat, 2 layers of ensolte, 1 layer of raamat....this is the best you can do short of concreting your floor...
Interesting. Do you just stick the raamat to the top of the ensolite, or how do you do that? I have up to 4 layers of raamat in the weakly supported places on the floor, and 1-2 layers of ensolite everywhere. I have extra though so maybe I will just start loading it up and see if that helps. I'm still convinced that most of the noise is coming from the floor, and the rest from the engine and windows/wind.

Eugenics
04-13-2007, 05:10 PM
So were you going to recommend a book or did you plan on leaving me hanging?

It's actually a fiction book that has nothing to do with car audio.

Buffalohed
04-13-2007, 05:20 PM
It's actually a fiction book that has nothing to do with car audio.

I see. Well, thanks for trying. I guess.

Eugenics
04-13-2007, 05:22 PM
I see. Well, thanks for trying. I guess.

Listen to hebrewhammer.

Buffalohed
04-13-2007, 05:27 PM
Listen to hebrewhammer.

It's mildly amusing how you went from being a ******** to seemingly trying to be helpful, almost like you felt a little guilty because you thought I was taking you seriously. :D At least that little exchange was semi-entertaining. Sort of.

WhoSayWho?
04-13-2007, 05:32 PM
almost like you felt a little guilty because you thought I was taking you seriously.

I think it is much more likely that he just got bored.

Buffalohed
04-13-2007, 05:33 PM
I think it is much more likely that he just got bored.

Welcome back. I hope you didn't get bored too?

Hebrew Hammer
04-13-2007, 05:39 PM
Interesting. Do you just stick the raamat to the top of the ensolite, or how do you do that? I have up to 4 layers of raamat in the weakly supported places on the floor, and 1-2 layers of ensolite everywhere. I have extra though so maybe I will just start loading it up and see if that helps. I'm still convinced that most of the noise is coming from the floor, and the rest from the engine and windows/wind.

I lay the 1st two layers or raamat...then spay glue down the ensolite...then lay to more layers of raamat down like normal.."making an ensolite sandwhich" then spray glue two more layers of ensolite, then 1 more layer or raamat like normal

keep in mind to...that once you lower the noise floor in the car...things like wind and engine noise seem louder, but in truth they were always there....just either masked by road noise or cancelled out acoustically...

req
04-13-2007, 06:51 PM
btw, most of the noise comes through door\window seals and the windows themselves. so short of double paned windows, its virtually impossible.

not the panels.

so good luck :p:

grouchy
04-13-2007, 10:27 PM
You can try adding some lamination to the inside of your windows. It might help reduce the wind noise a bit, plus help reduce reflections off the glass, plus add some extra security. That's what I plan to do.

Buffalohed
04-13-2007, 10:55 PM
You can try adding some lamination to the inside of your windows. It might help reduce the wind noise a bit, plus help reduce reflections off the glass, plus add some extra security. That's what I plan to do.

Interesting. What kind of lamination exactly, and where would I get it?

I've gone crazy with the silicone a couple times trying to make sure the back windows are completely sealed, but they still whistle loudly when I am going over 40. It pisses me off, but I've almost given up on getting them to stop now. I think it might just be the shape of the outside of the window frame that makes the whistling, in which case no amount of sealer will stop it.

grouchy
04-13-2007, 11:21 PM
Hi. You can see some more information here.

http://extremewindowsolutions.ca/automotive.htm

edit: It's not made to seal the spaces around the window though.

Buffalohed
04-14-2007, 01:37 AM
I wonder, can that be applied on top of the tinting I currently have on my windows?

Oh, another thing I had been thinking about was somehow weighing down the windows by attaching/coating something to the bottom of them in the door. Or maybe even putting many layers of raamat on them, so the increased mass of the window would decrease wind noise.

grouchy
04-14-2007, 01:54 AM
I wonder, can that be applied on top of the tinting I currently have on my windows?

Oh, another thing I had been thinking about was somehow weighing down the windows by attaching/coating something to the bottom of them in the door. Or maybe even putting many layers of raamat on them, so the increased mass of the window would decrease wind noise.



I see on their site it says "Automotive films can be applied over existing installed Security Laminates." so probably. Also they say"Choose from a variety of metallized high performance and conventional non-reflective automotive films, offered in a wide variety of light transmission levels designed to satisfy your local tint laws." So I guess you can get tinted laminate.

Buffalohed
04-14-2007, 02:00 AM
I'm definitely going to look into this. After I do some more work on my floor and see how that helps.

I have a 30lb bucket of butyl flashing cement and I might just go at it with that on the floor over the raamat, then redo the layer of ensolite and another of raamat. It's much cheaper and should serve the same purpose.

16.6V
04-14-2007, 06:55 AM
What cars are you driving? If you apply that much deadening the factory ventilation is completely screwed. It is likely that your cars are going to rust badly due to condensation and rain, or they will smell like *** after a while. Do you know that the water must flow freely inside of your doors?

To do the long term deadening, you have to keep open all ventilation holes, and apply fist layer of deadener on the hot metal so that condensation won't accumulate between two surfaces.

One layer of deadener goes on the deep inside surface of the door, second layer one on the outer surface of the door, and the third layer on the plastic upholstery.


It takes about 5-6 hours to correctly deaden 1 door by a pro!!! The pic is an example of how to deaden a door correctly. (Note: the third layer goes on the inside of upholstery, not on the top of the other layers!!!) After you apply these 3 layers, you start laying 4th,5th, and 6th layer of deadener if you want, but again, you MUST keep ventilation and drainage holes at the bottom of the door/body - 100% open.

Ex of 1st and 2nd layer of the CORRECT deadening job:

http://i160.photobucket.com/albums/t193/bad_silver/IMG_0110.jpg

16.6V
04-14-2007, 07:07 AM
When people say that they have deadened a door, they actually have 3 layers!!! and when they say they have double deadened a door, they actually have 6 layer of deadener!!! and when they say that they have tipple deadened a door, they actually have 9 layers!!! :cool:

PremierAudio
04-14-2007, 08:40 AM
Are saying that people on here actually triple their efforts when they say they applied a layer of sound deadening? Or are you talking about a professional? Either the case, I have seen many installers put down exactly how many layers they say they would. Not sure why someone especially an installer would go the extra mile and give a customer 2 extra layer or even 4 extra layers (double deadend) for free. None the less, ventilation is good in our cars, allows you to shut your doors, keep condensation down, keeps mold down, etc.. But if you are try achieve a solid door or car for competition, SPL or SQ, you will want them completely sealed off. Its really a give and take situation.

Oh and if it takes a pro 5-6 hours per door, and they are only installing a few layers, they probably do not know what they are doing and they would most likely be fired. If they were even doing it leisurely, I still dont know what to think about that.

Back to the original poster, Like Hebrew said, I also Sandwhich my ensolite between my deadener. This is about the best approach I have come up with, without using acoustic foam. Foam is about the best bet for knocking down those unwanted noise. But you will only reach a certain reduction in different cars, until the windows and designs start to come into play. That of which you can usually do nothing about. Cars are just not the perfect enviroment for audio..I guess thats what pushes us to achieve better things in them?

16.6V
04-14-2007, 08:46 AM
Are saying that people on here actually triple their efforts when they say they applied a layer of sound deadening? Or are you talking about a professional? Either the case, I have seen many installers put down exactly how many layers they say they would. Not sure why someone especially an installer would go the extra mile and give a customer 2 extra layer or even 4 extra layers (double deadend) for free. None the less, ventilation is good in our cars, allows you to shut your doors, keep condensation down, keeps mold down, etc.. But if you are try achieve a solid door or car for competition, SPL or SQ, you will want them completely sealed off. Its really a give and take situation.

Oh and if it takes a pro 5-6 hours per door, and they are only installing a few layers, they probably do not know what they are doing and they would most likely be fired. If they were even doing it leisurely, I still dont know what to think about that.

Back to the original poster, Like Hebrew said, I also Sandwhich my ensolite between my deadener. This is about the best approach I have come up with, without using acoustic foam. Foam is about the best bet for knocking down those unwanted noise. But you will only reach a certain reduction in different cars, until the windows and designs start to come into play. That of which you can usually do nothing about. Cars are just not the perfect enviroment for audio..I guess thats what pushes us to achieve better things in them?


I learned that from installers that work with expensive cars in expensive audio shops, not best-buy installers. :confused:

In fact, it takes a shop 1-2 weeks to do proper audio install.

Buffalohed
04-14-2007, 12:12 PM
I have actually considered that I am vastly altering the "flow" of my car so to speak. I noticed when I first deadened my floor that there is some moisture and wetness on the metal under the footmats. Also the inside of my doors get wet sometimes, obviously.

As for deadening the way you described, that is exactly how my two front doors are done. With 2 layers and 2 of ensolite, and clay and MDF. My two rear ones I removed the window motors, deadened with raammat and then completely filled with great stuff. Water shouldn't even get in the rear doors at all though because I have siliconed the windows as well. Hopefully that isn't an issue, but I will address it as it arises.

How much do you guys think I would notice by deadening my hood and parts of the engine compartment I can access?

Gary S
04-14-2007, 03:25 PM
I'm beginning to realize a couple things about achieving SQ in a car.

1. You are ultimately limited by sound proofing and the acoustical properties of your car. I have put tons and tons of time and money into deadening my car and there is still a lot of noise that comes in, from many different sources. Unless I can figure out how to silence it, my car can only sound so good while driving.



- Yes, you could get into your car and never get out trying to sound proof it better. Road noise is a big problem. One thing some people could do and that is never talked about is engine noise. One of the best things I ever did was have a quite, Cadillac-like muffler installed on a Z-28.







2. Rear fill provides a nice "sound experience", for lack of a better term, but it inevitably detracts from sound quality and accuracy. I have found that while I enjoy having sound all around me, and the rear fill adds a lot of depth (largely I think because it bounces off the rear window), there is a significant trade-off for accuracy, tonality, and response curve when you go with rear fill. When I figure out how to raise and widen my soundstage I will be golden, because right now it is pretty low, and there is a lot of interference between my tweeters due to placement.



- Surround sound, specifically a rear channel surround sound signal fed to the rear speakers would solve all those problems and more... if well implemented... speaker placement is important there also.


Your weakest point is your speaker placement... kick panels are the way to go.

Before buying a car that I want to put a good system in, the first thing I look for is speaker locations. Pick up Trucks are no good, a car will always beat them.

grouchy
04-14-2007, 05:32 PM
What cars are you driving? If you apply that much deadening the factory ventilation is completely screwed. It is likely that your cars are going to rust badly due to condensation and rain, or they will smell like *** after a while. Do you know that the water must flow freely inside of your doors?

To do the long term deadening, you have to keep open all ventilation holes, and apply fist layer of deadener on the hot metal so that condensation won't accumulate between two surfaces.

One layer of deadener goes on the deep inside surface of the door, second layer one on the outer surface of the door, and the third layer on the plastic upholstery.


It takes about 5-6 hours to correctly deaden 1 door by a pro!!! The pic is an example of how to deaden a door correctly. (Note: the third layer goes on the inside of upholstery, not on the top of the other layers!!!) After you apply these 3 layers, you start laying 4th,5th, and 6th layer of deadener if you want, but again, you MUST keep ventilation and drainage holes at the bottom of the door/body - 100% open.

Ex of 1st and 2nd layer of the CORRECT deadening job:

http://i160.photobucket.com/albums/t193/bad_silver/IMG_0110.jpg

I have a toyota echo. Don't know exactly how all the soundproofing was done to my car, as I paid an installer to do it. I guess I could ask them about condensation, but they do good work so I think it will probably be ok. You can see some pictures here
http://hzemall.com/our_gallery/installs/2005_toyota_echo/install2.htm

16.6V
04-15-2007, 12:45 AM
Sound deadening is one thing that you should really do yourself, unless you want to spend your time on finding a knowledgeable installer and give him about $2000 to do the job + the price of the deadener. After all, it is very basic stuff, but requires a lot of effort and persistence.

Jut strip your car to bare metal and inspect the surface for ventilation holes and drainage holes. The take an electric heat gun (can be had for about $40 in most home improvement stores) that and begin to heat the metal until it is just too hot to touch. Then apply precut peaces of deadener. Also, NEVER put the whole peace of deadener on the surface but try to press it inch by inch very slowly. Unless you deadening your roof NEVER use roller on doors because you can’t apply adequate pressure on curved surfaces. Usually pros use the back of a screwdriver to correctly deaden curved surfaces as they lay deadener on hot metal. :cool:

My advice to all armature car-audio lovers is to deaden one area at a time. One Sunday you deaden one door, the next weekend you deaden the other door etc.. until you are done with all car. If you will try to deaden the whole thing in one long session the chances are that you are going to get tired and f*ck your car. :verymad: Expect to spend at least 6-7h on one door…


The goal to is make as little modifications to car’s ventilation system as possible while provide better soundproofing. Remember that factory engenders are not a bunch of idiots and every whole inside of your vehicle was put there on purpose – which is to increase the lifespan of your vehicle. ;)