sound deadening question

[mrray13 30]

you actually gain more output because the energy is not being converted and being lost to rattle.

cool thats wut i needed 2know. thanx, ill b deadening soon

you won't always gain by deadening. sometimes it can hurt overall output. however, it will definitely sound better.

and yes, deaden your trunk at the very least!

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[KU40 173]

LOL does every thing you say have to be so negative?

It wouldn't be if there weren't stupid posts. If I had full run of the forum, the rules would be different but first off not using grammar would get you warned the first time and banned the second. It is just rude to come into someones house and not spend the time to actually try to ask the question you want. I'd also require that each post started with a phrase like "I searched for xxxx, and xxx, and xxx but couldn't find an answer...." I'd also have a pretty much zero tolerance policy. Perhaps you don't realize how many threads some of us have to read. It is really deflating when crap like this happens and makes those of us who put in a lot of time waste time which sucks.

I read this thread right after he posted it. I was going to reply until I actually read the post. So I agree. I pass up on replying just because the poster sounds so unintelligent that it's not worth my time because more than likely I'll have to post 4 more times explaining what I posted the first time.

Edited July 7, 2008 by KU40

[JimJ 11]

I might be able to do the front doors but I would like to avoid that as well.

If you want the best midbass response possible, and it's not an extremely high-end luxury vehicle with a lot of deadening already installed, you're going to have to, I'm afraid.

But it's well worth it

[///M5 2,833]

Nope, he is just trying to act cool and failing miserably. Firefox has a spell checker which easily solves all the problems above. Grammar doesn't have to be perfect but at least attempted. If you won't try to make a coherent post no one here will try to give you an answer. The only difference is that I am here letting him know that all he has to do is change how he types and the reactions will be different, the others just ignore it.

So this was not a personal shot? Don't get me wrong, I'm by no means throwing a fit. You have a point, but you can use tact with someone new to forums.

So if you weren't trying to act cool what was the point of the ghetto talk? And no I wouldn't call it a personal shot, just citing facts.

Ok I hope the point was made and understood. Now back to the topic, did you have a specific question about where/how much/layers etc. of deadener?

No, because my question was answered before all this other stuff. I'm planning on 1 layer of Damplifier and 1 of Overkill. Unless you would suggest otherwise.

Not so sure it was answered. You are interested in output, I wouldn't expect deadening to help your output at all and in fact might hurt it. Again it depends all on your goals.

[Darkhunter139 1]

I might be able to do the front doors but I would like to avoid that as well.

If you want the best midbass response possible, and it's not an extremely high-end luxury vehicle with a lot of deadening already installed, you're going to have to, I'm afraid.

But it's well worth it

Do you think 60 sq feet will be enough to do my trunk and the two front doors? Its a 94 Accord EX

Edited July 8, 2008 by darkhunter139

[///M5 2,833]

I might be able to do the front doors but I would like to avoid that as well.

If you want the best midbass response possible, and it's not an extremely high-end luxury vehicle with a lot of deadening already installed, you're going to have to, I'm afraid.

But it's well worth it

Do you think 60 sq feet will be enough to do my trunk and the two front doors? Its a 94 Accord EX

Some of us have more than that in our doors, again it depends on your goals. Either way it would be a hell of a start.

[Darkhunter139 1]

I guess my best bet would be to order a roll of rammat and see where it gets me. Thanks

I just want to try and get a decent sounding system without spending thousands of dollars. I still need comps and deadener then I am good to go

[emperorjj1 2]

60sq ft should be plenty for trunk and doors. You dont have to go crazy and use 60sq in the doors... thats loco

[Dr Durden 0]

I might be able to do the front doors but I would like to avoid that as well.

If you want the best midbass response possible, and it's not an extremely high-end luxury vehicle with a lot of deadening already installed, you're going to have to, I'm afraid.

But it's well worth it

While I generally agree, we have to use the term "deadening" pretty selectively. Most associate "deadening" with the app of CLD mat (ie Dynamat). But a simple cross brace on the driver mounting surface might do the trick depending on which driver is in door and the freqs it's playing.

LOTS of forum-goers have been misled with the notion that CLD is mass loading, as in the goal with CLD mat is to add mass. Sure, you're adding mass but this is not really what you're after. If you want to add mass, then cross brace and pack around it with non-hardening modeling clay. Better yet, mass load the clay with chunks of rubber, lead, or steel....or something that's dense and heavy.

My $.02 after using CLD mat and every other "deadening" product in my doors and all over my car.

Edited July 8, 2008 by FoxPro5

[KU40 173]

While I generally agree, we have to use the term "deadening" pretty selectively. Most associate "deadening" with the app of CLD mat (ie Dynamat). But a simple cross brace on the driver mounting surface might do the trick depending on which driver is in door and the freqs it's playing.

LOTS of forum-goers have been misled with the notion that CLD is mass loading, as in the goal with CLD mat is to add mass. Sure, you're adding mass but this is not really what you're after. If you want to add mass, then cross brace and pack around it with non-hardening modeling clay. Better yet, mass load the clay with chunks of rubber, lead, or steel....or something that's dense and heavy.

My $.02 after using CLD mat and every other "deadening" product in my doors and all over my car.

Yeah there are two different reasons for adding mat. One I suppose is mass loading to get rid of the tin-can sound (or adding something that will either reflect or absorb the sound, as in the case of foam). Another is to cover up holes in the door to effectively separate the front and rear waves to create an IB setup in the door.

[theabunai 3]

While I generally agree, we have to use the term "deadening" pretty selectively. Most associate "deadening" with the app of CLD mat (ie Dynamat). But a simple cross brace on the driver mounting surface might do the trick depending on which driver is in door and the freqs it's playing.

Foxpro, or any other experienced audiophile, when you say "cross brace" do you mean a piece of metal across the surface or are you referring to a small strip of deadener across the surface of the door ??

[Dr Durden 0]

Yeah there are two different reasons for adding mat. One I suppose is mass loading to get rid of the tin-can sound (or adding something that will either reflect or absorb the sound, as in the case of foam). Another is to cover up holes in the door to effectively separate the front and rear waves to create an IB setup in the door.

A constrained layer damping system (butylene rubber composite + sufficient aluminum foil) is designed to convert vibration to heat. Heavier "deadener" isn't better; more effect damping (CLD or otherwise) IS. A perfect example is something like mineral-loaded vinyl damping sheets (Parts Express, Cascade VB-2) which has no constraining layer, is lighter, but will out damp a CLD mat.

A thick layer of Skippy Extra Chunky peanut butter has more mass than a single layer of Dynamat Extreme, but it's not going to work. Damping is dependent on the visco (water-like) elastic (ability to return to form) nature of the damping material, not on weight. Weight is just one element.

Reflection is a different physical phenomenon.

Absorption is a different physical phenomenon.

Point is, different materials do different things - although they do overlap.

IME the best way to properly attenuate [do we ever get rid of it?] the back wave is to make a proper baffle. A crazy Kiwi dude that's on a few car audio forums once told me that a baffle is the device that creates a loudspeaker, not necessarily a dead door.

Anyway, enough rambling. HTH.

[Dr Durden 0]

when you say "cross brace" do you mean a piece of metal across the surface

Yes. This will raise the RF of the door, most likely. Adding mass will probably drop it back down.

IMHO, once you cannot locate the driver, it's dead as dead.

[Big E 4]

Are you looking to be loud inside the car, or loud so your homies on the other side of town can hear you coming? If the latter, you're going to be thoroughly disappointed by the sound deadening. Otherwise, it shouldn't be too much louder...it'll just sound a LOT better.

Oh, and FYI, once you get used to typing proper grammar, it's actually harder to type "internet lingo".

Edited July 8, 2008 by Big E

[theabunai 3]

when you say "cross brace" do you mean a piece of metal across the surface

Yes. This will raise the RF of the door, most likely. Adding mass will probably drop it back down.

IMHO, once you cannot locate the driver, it's dead as dead.

Foxpro i find this very interesting... I've never seen this...

How would one go about doing this?

let me clarify, I'm certain it will be attached either with a high bond epoxy or tack weld. but how would you form and position the cross brace ?

Maybe i am imagining it a bit different (i'm envisioning a cross brace similar to what is holding the roof from rattling in the car) is this what you had in mind ?

If you got a picture i would love to see an example of it...

[JimJ 11]

You dont have to go crazy and use 60sq in the doors... thats loco

I have big doors

[///M5 2,833]

While I generally agree, we have to use the term "deadening" pretty selectively. Most associate "deadening" with the app of CLD mat (ie Dynamat). But a simple cross brace on the driver mounting surface might do the trick depending on which driver is in door and the freqs it's playing.

LOTS of forum-goers have been misled with the notion that CLD is mass loading, as in the goal with CLD mat is to add mass. Sure, you're adding mass but this is not really what you're after. If you want to add mass, then cross brace and pack around it with non-hardening modeling clay. Better yet, mass load the clay with chunks of rubber, lead, or steel....or something that's dense and heavy.

My $.02 after using CLD mat and every other "deadening" product in my doors and all over my car.

Perhaps you should drive a Chevy once, my doors needed a shit ton of CLD to stop being huge resonant amplifiers. On the opposite note, and not surprisingly the M5 even when nearly 20 years old fared WAY better.

While I agree that the term mass loading is confusing, it is used in NVH engineering to mean anything that shifts a resonance and the damping characteristics of a particular device. In this case of course the mass is the least important but really the damping. Note, I am using the word damping and not dampening. The distinction of course comes to the amount of ringing that the targeted area is left with in the end. With a door or any surface near a radiating driver we obviously want things to be critically damped and not ring. The mass loading in this case both changes the resonance and significantly alters the actual response of the skin which is the final goal. The misnomer of course occurs when translated into normal terms and all that is focused on is the addition of mass which is only a small part of the puzzle. The bottom line is that the true goal is to prevent the panels from resonating and adding energy where we don't want it in the acoustic response. Of course this is completely and 100% different than acoustic absorption which is done in a completely different method.

Your description of a cross brace is spot on as well. A ton of coloration of sound definitely comes from a piss poor baffle and is also necessary. Again the mass addition as long as it is a flexible energy absorbent substance can surely help in the damping of the area around the baffle and is required, but adding stiffness to prevent flexure is also important to minimize any coloration.

[Darkhunter139 1]

Is there anything cheaper then rammat that is actually decent

[///M5 2,833]

Not really.

[Tmax98 3]

Is there anything cheaper then rammat that is actually decent

its very well priced compared to dynamat

it may not be as efficient, but is well worth the money

and when running double layers is still cheaper the dynamat if i recall correctly

and rick is a great guy on top of that

im sure others have some 2 cents on this

[emperorjj1 2]

You dont have to go crazy and use 60sq in the doors... thats loco

I have big doors

lol

[Dr Durden 0]

While I agree that the term mass loading is confusing, it is used in NVH engineering to mean anything that shifts a resonance and the damping characteristics of a particular device. In this case of course the mass is the least important but really the damping. Note, I am using the word damping and not dampening. The distinction of course comes to the amount of ringing that the targeted area is left with in the end. With a door or any surface near a radiating driver we obviously want things to be critically damped and not ring. The mass loading in this case both changes the resonance and significantly alters the actual response of the skin which is the final goal. The misnomer of course occurs when translated into normal terms and all that is focused on is the addition of mass which is only a small part of the puzzle. The bottom line is that the true goal is to prevent the panels from resonating and adding energy where we don't want it in the acoustic response. Of course this is completely and 100% different than acoustic absorption which is done in a completely different method.

Yea, totally! Pretty much what I was thinking but couldn't spit out in my reply. So smart, you are.

My disgust with "mass loading" comes from several members on lots of forums who seem to be hopelessly addicted to the following notion: Mat is for mass loading, no more, no less. If you really think about it, it makes no sense because the most popular deadening mats everyone knows and loves are not HEAVY!

Edited July 9, 2008 by FoxPro5

[Dr Durden 0]

Foxpro i find this very interesting... I've never seen this...

How would one go about doing this?

let me clarify, I'm certain it will be attached either with a high bond epoxy or tack weld. but how would you form and position the cross brace ?

Maybe i am imagining it a bit different (i'm envisioning a cross brace similar to what is holding the roof from rattling in the car) is this what you had in mind ?

If you got a picture i would love to see an example of it...

Structural damping has many forms and doing something like cross bracing a closed-termination device [think of the door panel as a snare drum] may be all you need to do what ///M5 just mentioned.

You could use an epoxy I suppose. I used a marine epoxy in my baffle construction and it's withstood a beating from some pretty potent 8" midbass and subs mounted to it.

You could also screw it to the door itself where ever you have room and a good, long stretch of open door....preferrably to connect one side to the other. In my mind, the vibration will take the path of least resistance through the brace rather than through the center where vibration is probably the highest? Not too sure.

No pic, sorry. If you search Ge0's install log on DIYMA, he did something just like this with cross-bracing and mass loaded clay.

[Darkhunter139 1]

I might be able to get some rammat from someone on CA.com for 80 plus ship

Thats a great deal

He has two rolls so I am tempted to just buy both but I dont know if I can afford it right now. I am definitely getting one though

[Darkhunter139 1]

I can get two rolls for $180 or 1 for 100 shipped

Ugh what to do