Dynamat-ing

[firelizard]

1998 Mazda Protege

I am going to buy 1 (one) 32"x18" sheet of Dynamat Extreme and I am looking to make the most of it. The problem areas for vibration are the front doors and the rear deck. The front doors currently house stock speakers but buzz at the slightest hint of bass. The rear deck vibrates quite violently when the volume is turned up, thanks to the aftermarket Pioneer 6x9 3-way speakers I installed.

I have two questions really. The first is "Should I put the Dynamat on the top or bottom of the rear deck?" And the second is "Should I use the entire 32"x18" sheet on the rear deck, and simply get more for the doors later, or should I "spread the love" so I can quiet the entire car a bit right now?"

The reason I'm only getting 1 sheet at the moment is my budget...it's small.

[blue LEDz]

you might not want to use the dynamat on the rear deck. find out exactly what is vibrating and go from there. with the rear deck, it usually vibrates against the back window. 99% of the time some weather stripping can cure the rear deck rattles.

[firelizard]

What's vibrating (apart from the whole deck..it's just one thickness of metal) is all the clips for wires and the clips holding in the 3rd brake light and the rear deck panel (carpeted piece of composite). I figured Dynamat would also keep the vibration from those speakers from spreading through the car as much.

[Suzuka323]

Dynamat works more like a barrier for sound, to keep it from escaping so to speak.

Example: You have subs in the trunk and the trunk rattles horribly, that's because the bass created from the subs is hitting that bare metal trunk lid. Now add Dynamat to the trunklid and the bass is now reflected back into the trunk of the car, there's still some thumping from the lid, but not near as much.

Example: I have a component set in my doors, and from the outside of the car you could hear my music perfectly because of the bare metal inside the door. After I added a sheet of Dynamat to the inside of the door behind the speaker, it reflected the sound back towards the inside of the car and dampened the music heard on the outside by a substantial amount.

So in short, by sticking it on the surface that is rattling, it won't keep it from doing so, you need to find a better way to secure the things that you mentioned above. If it's the clips vibrating, a little piece of ducttape over the tops of the clips and wires should take care of that problem. All dynamat is going to do by sticking it under the panel is keep the sound in your cabin area, but probably won't eliminate the rattle from the clips and rear deck.

I had the same problem with my last car. God I love having a hatchback, the most sound friendly design EVER!

Good Luck to ya.

[blue LEDz]

actually dynamat is not acoustical barrier. it's a sheet metal dampener. it works by adding mass to the metal to reduce the metal vibration. dynamat would work well to cover the wires and plastic connectors, but good luck if you ever need to service them.

[jnorion]

If you're going to use it on the rear deck, you might want to put a layer between the connectors and the metal of the deck. It'll strengthen the metal and keep it from vibrating, and act as a pad between the rattling plastic and the metal, but you'll still be able to get at the plugs if you need to.

[firelizard]

Thanks for the input guys. Looks like I"ll be getting 20sqft of B-Quiet Ultimate to play with.

[firelizard]

Sorry for the double-post, I'm *bump*-ing at the same time

I'm just wondering if you guys have any tips before I dive in, while we're on the dampener topic. I'm working out a deal for 20sq ft of B-Quiet as I said, so obviously I'm anxious and excited. However I'm also afraid to screw up my one and only car so if you guys have any useful hints or tips or advice on how to handle installing it, lets hear 'em!

thanks

[blue LEDz]

don't put it anywhere that is visible with the panels, carpet, and trim installed. also, buy more than 20 sq ft, that's not gonna do much.

[beetle_orange]

let us know how it comes out and post lots of pictures

[firelizard]

also, buy more than 20 sq ft, that's not gonna do much.

It won't? A Dynamat door kit is only 4 sqft. I don't need to go crazy with it right off the bat anyways, it can always get more later. I just need the rear deck and the front doors critically.

Oh, btw, I checked out the rear deck, and it's the whole thing that vibrates when the bass pounds, it's not touching anything (I took off the panel and everything) but it's moving enough air with its up-down motion to make noise. Most of the clip rattles will be solved with duct tape.

[blue LEDz]

i've got over 300 sq ft of raammat bxt in my truck. it's probably over 20 sq ft per door

[firelizard]

Yeah, but you're all crazy n' **** lol
For a normal person 20 sqft oughta be a good start eh