Editing Sound Deadening

==Deadening Doors==

===Intro===

I have recently finished sound deadening the doors on the Skyline.  Since I've done this before I'm not surprised with the improvement but if you haven't done it before you WILL be surprised.

Some people don't like to sound deaden their doors thinking that they dont need to. WRONG. Put simply to seal and sound deaden your door provides the best bang for buck upgrade that can be had for your audio system.

OK, a little of information before we get into what's involved. If you don't want to read this then feel free to scroll ahead.

Basically this process aims at achieving two things.

* 1) Sound deadening door panels will reduce the road noise and the rattles caused by those big ass drivers in your doors.

* 2) Sealing your door creates an enclosure for your drivers.  Basically we are using the door cavity as a box!!

Sound deadening doors simply aims at adding mass to the door panel in order to reduce the resonant frequency of the door panel.  What happens is that the high and low pressure that your speaker makes in the air causes the door skin to move in and out, just like another speaker!! This is bad since this causes more noise through rattles and the like. Solution, add more mass!!

Secondly the sound deadening helps reduce the transmission of road noise through the door skins. This is achieved simply by adding more material to the door.

Thirdly by sealing your doors then effectively what we are doing is building a box for your drivers.  This has two advantages.

* 1) The air does not escape from the door.  This means the backwave from the speaker doesn't leak into the cabin. This means that your driver can produce louder and 'punchier' bass.

* 2) This is a very minor point but by sealing the door we can use the pressurised door cavity as suspension for your cone, adding more cone control. but this is pretty insignificant unlike a sub box.

OK for those who want to read a bit more on how to reduce noise read this link:

http://www.grc.nasa.gov/WWW/AcousticalTest/Industrial/Vibration_Control.html

Pretty much simplified version of what occurs.

===OK ONTO THE SOUND DEADENING===

What you will need:
*Sound deadening; this comes in a mat, spray can or paint on version. always go for the mat because you can put a lot more weight on the door than you can with the paint on stuff.  The draw back is that it 'seems' way more expensive. I always try to convince people to hold up a can of spray on and feel the weight.  Then pick up your sound deadening mat and feel the weight.  That difference is significant.  It's always cheaper to use sound deadening mat to do the job.

:Brands to look for; Stinger Roadkill and Dynamat both make very high quality stuff but you have to pay for it.

:I myself use some stuff called DFQ Ultra (pm me if you want some) which is much better value for money.

:You can also get other brands but remember you get what you pay for.  A lot of cheap stuff doesn't stick well and will fall off in no time flat.

*Grease Remover: Turpentine is a bit harsh and will strip the paint pretty easily, but then again this isn't a real problem because your gonna sound deaden over the exposed metal anyway. If you're worried about rust then use some specialist grease remover. It's just watered down turps anyway.
                       
*Heat Gun: It is very important to use a heat gun to heat the mat so that it becomes more flexible and also so that you 'activate' the glue.  This is a MUST do.  A blow dryer suffices.

In this tutorial I am going to call the two door skins the inner skin and the outer skin.  The inner skin is the door skin that is closest to the interior.  The outer skin is the skin you can see from outside the vehicle.

OK so the process:

* Step 1) Remove the door trim. If you dont know how [[Door trim -Removal|LOOK IT UP IN THE TECH INFO SECTION OF THIS SITE!!!]]

* Step 2) Remove the grease and dirt from the door skin.  This is going to take you a fair while to do.  Please please ensure you clean it very well since no sound deadener will stick to your door if it's covered in shit.  What I do is first remove most of the big bits of dirt from the door with a rag soaked in turps.  Then when it looks really clean, I scrub the door again with turps and a clean rag just to make sure.

* Step 3) Apply the sound deadener to the outer skin.  To do this simply cut out a small bit of deadener and heat the material up.  Then pull some of the backing off so the sticky bit is exposed and stick that to your door.  Rub it onto the metal really hard making sure that you rub ALL of the material.  If your hand doesnt hurt after 5 minutes you ain't doing it properly.

:For best results add two layers over the area behind the speaker.  Then deaden the side intrusion bar.  This is the raised strip of metal that runs along the length of your outer door skin about half way up the door (it's about 200mm wide) this always rattles so it's best to deaden it.  It is up to you whether you deaden the rest of the outer door skin.  It doesn't cotribute to lowering the noise floor but it will keep the sound in your vehicle so you dont look like a wanker when you have your music cranked.

* Step 4) See all those lovely control rods for your handle and locks??  They LOVE to rattle.  Best way of preventing them from rattling is to run over to your local foam and rubber shop and buy some rubber pipe.  Try to find some stuff that is real flexible and has a pretty thin wall.  Then all you have to do is slide the pipe over the rod.

* Step 5) Apply the deadener to your inner door skin.  Do the same as before however this time you want to cover all the metal of the door skin.  This is where you will kill most of the road noise so do it well!!!  BUT don't deaden over the really large inspection holes or over your control rods.  We will get to the inspection holes next.

* Step 6) Seal the door.  This is straight forward.  Cut out some bits of MDF or whatever material you have lying around that is nice and stiff.  Add a layer of sound deadening over it.  Then stuff it into the hole in the door and simply duct tape it into place.  By duct taping it into place you can remove it later.  Use LOTS of duct tape.

* Step 7) Sound deaden your door trim!!  This loves to rattle so it can't hurt to add some deadener to that as well.

* Step Cool) Grab a beer you need one for motivation.  Coz there is another door you have to do yet!!!



Here's a pic of my front door:

[[Image:Sdead_6.jpg]]

So there you have it.  Some nice solid sound deadened doors!! - '''SCorpion'''




==Rattling Bumpers==

Hey Everyone, I've finally decided to put this thread up on what i did to combat some of my boot rattle, mainly the rear bumper! The rear bumper is two pieces, plastic skin, and reinforcement bar,the rattles occur mainly between the two, and as you all know, the sides of the bumpers that you can hear in the cabin!!!! Way to over come this problem is to add mass to all areas where there is any kind of gap.

Things you will Need to this:
- a weekend if you have never done it and LOTS of patiants took me 7 hours all up!
- basic tools including ssockets, wrenches screw drivers
- a good stanley knife
- PREPSOL, this is very important!
- and lastly some sound deadener, heres the interesting bit, I didnt use sound deader that you buy at auto barn for $180 or what not, all it really is, is tar with aluminium on it, which what is used inside house gutters for repairs, and means you can get it cheap at bunnings  Grin
heres a pic, get 2 rolls of the 35metres by 100mm wide, this will do your whole bumpe easily and cost about $70

[[Image:Sdead_1.jpg]]

First Step, get the rear bumper off!, there are four bolts under the car that need to be undone, 8 little bolts insidea the boot on either side of the boot ( behind the rear tyre, and behind where the stock jack goes) and finally theres 2 screws on each side of the car under the rear gaurds! you cant miss them!

Once the bumper is off, take it apart, this includes taking the reo off, and the metal plates on either side of the bumper, in total you should have it 4 pieces.

Then with soap and water watch the inside of the bumper getting all the dirt off, this will save alot of time instead of using litres of prepsol.

Once this is done, on the sides of the bumper, clean the inside with prepsol really well, and let it dry.  and start applying the deadenor,

[[Image:Sdead_2.jpg]]

do this to both sides, and do 2 layers! and do both sides!

Now, there are also two metal side pieces which both have rectanglular wholes,Start by cleaning them with prepsol and  apply the sound deadener over these wholes, on both sides of the metal pieces, and put them back onto the sides , if you have done it right, it should be abit of a tight fit,  and the plastice bit of the bumper should feel quite abit heavier!

[[Image:Sdead_3.jpg]]

Now for reo! once you do the sides, and not  the reo, the middle of the bumper rattles like theres no tommorow! In order to stop this, you need to target the main areas of the bumper skin which sit loose on the reo! mainly the top bit and bottom bit of the reo are the loosest, now, if you really want to eliminate all the rattles, i would recommend 3 layers of this stuff, i've done 2 and i still have a few rattles, but I cant be bothered taking the rear bumper off to do it!

Start by Cleaning with prepsol, make sure ALL dirt is off it, and take your time with this bit, as need to be done well!

[[Image:Sdead_4.jpg]]

[[Image:Sdead_5.jpg]]

If you have any question feel free to pm me and ill do my best to assist! Oh and one last thing, once you have done this, there should be a noticable differene in weight when you lift it up afterwards, i was quite suprised at the difference.

Now, when putting the bumper back on, thee air vent behind the tyre will be an issue, i recommend not taking it off permanently, from my last r31 I found it causes more rattles to take it off then leave it on! so take it off, and before you do take note on how there is about 3 mm of plastic sticking out, take the air vent off and trim this off! then you will have no issues putting the bumper back on!

Cheers '''Steve (mrskyliner31)'''




==Miscellaneous Forum Posts==

===Tru-fit Carpets===

Autobahn wont stock Dynamat, try a car audio retail and installation place. When I went searcing for this stuff I was quoted about $80 I think it was for about 100cm x 30cm so its quite expensive.

Instead I spotted something at Tru-Fit Carpets, they have sound deadener for floors, boots etc for cars or marine, comes in 200cm x 150cm so you have heaps to do the lid and sides, and best of all cost something like $35. While the Dynamat has special textures etc in betwen the layers to stop reverb, this carpet roll had big black think shit tar like stuff between thick cushioney carpet, and did a good job at weighing the boot lid down to stop it rattling so much. I also noticed a better bass response from inside and outside the car.

I have also heard that something similar can be picked up at your bunnings for a cheap price, seek on these forums and you may find - '''Anfz'''

===Autotrimming Wholesaler===

Dad and I purchased waterproof sound deadening material (approximately 18mm thick) for the inside of the door panels, as well as multi-layered heat & flame resistant material (approximately 20mm thick) through an automotive and marine autotrimming wholesaler / distributor in Smithfield, as well as a roll of deadening quilting.  We paid about $200 all up, and we have rolls about 2 metres tall, and four metres long, for each type of material.

Far better quality, far more effective, and far less expensive than any of that ripoff flashtrack crap, or anything Jaycar / Super Cheap Auto / Autobahn sell. - '''Mark E'''

===Gspot===

I bought 2 sheets of Gspot flexi max sound deadener, 1350X650mm each, for $150.
This stuff is damn heavy, and should do the trick nicely, once I get around to putting it in  Roll Eyes
With this stuff, all you have to do is peel of the backing and stick it to the door. Couldn't be easier! - '''Patmanspost'''

[[Category:Cosmetic]]
[[Category:Audio]]