How to soundproof your BRZ

[ebgs500e]

I wanted to add soundproofing to the BRZ while keeping the weight in check. Here is what I did.

Materials:
Flat head screw driver
Phillips head screw driver
Panel removal tool
MLV 1/4 inch, 1Lb per square foot. (bought 60 square ft, used 40, scrapped 20). This added 40 Lb to the car.
3M thinsulate Acoustic 1/8 inch (bought 50 square feet, used about 15). This stuff is light. Did not add anything to the car.
Dynamat extreme CLD 0.35 Lb per square foot. (bought the door kit with 12 square feet. used 8 square feet total for doors and trunk). This added 2.5 pounds to the car.
Tennis ball
Garbage bags
duct tape

Total cost $250

Front Doors:
1) CLD to deaden the sound. 3 ft² total for both doors. Two 12x6 inch pieces to the top of the outed door skin. One 6x6 inch piece behind the speaker.
2) 3M Thinsulate Acoustic, 18 ft² (9ft² for each door to have 1 layer between inner wall and MLV and 1 layer between MLV and trim panel). scraps will fill the spaces in the trim panel.
3) MLV 1/4", 1Lb/ft², 12 ft² (two 3x2ft pieces).


Front foot wells:
1) MLV 1/4", 1Lb/ft², 18ft² (two 3x3ft pieces). Note: the driver's side is a little larger than the passenger side.


Rear seat back:
1) MLV 1/4", 1Lb/ft², 6ft² (one 3.3x2ft)
2) CCF (3M Thinsulate Acoustic), 6ft² (one 3.3x2ft)


Rear seat bottom and rear seat foot wells:
1) MLV 1/4", 1Lb/ft², 16.5ft² (one 3.3x5ft piece)


Trunk:
1) CLD 4ft²


Here are the pictures and directions on Flickr

Enjoy.

[edward]

Thanks! Do you have any measurements? Either quantitative, or "it sounds quieter" :p

[ebgs500e]

Before I started, the car was 66 Db.

When I finished the doors, rear seat back, and passenger side foot well, I had a 6 Db reduction in noise. at driver seat head level going 70 MPH on asphalt.

Now that I have the car done, I will be driving the same route to work tomorrow and will take more measurements.

The measurements were done with a smart phone app, and I took an average of the many data points the app collected.

[ebgs500e]

So... 70 MPh is now 58 Db on Asphalt. That is an 8 Db decrease and a very noticeable improvement in noise. I can now speak on the Bluetooth handsfree going highway speeds and the other people actually hear me!!!

[brzninja]

Very nice, sir!

[michaelahess]

I'm on my way to getting mine done as well. Got MLV in the entire trunk. One big piece the size of the drop in carpet, 2 large pieces behind the carpeted sides filling in 98% of the area, then another big long piece draped against the back held down by the plastic piece the trunk latch goes through. CLD under pretty much all of it.

I took out the entire carpet piece in the back seat and cut MLV and glued it, not fun. Then sheets of MLV and CLD under both seats. Need to do the quarter panels behind the plastic, will do the same.

The doors have no MLV, just a full inner coat of CLD followed by a second skin on the door panel. I will be putting some of that accoustic foam on that as well as the rear quarters.

Didn't think to do the front floor for some reason. Do you think that made a big difference what with the 1" foam already under the carpet?

My trunk is dead quite, the front seems pretty good, but I still get a lot of noise from the rear quarters since they aren't treated. It's a very noticeable difference in fact.

That thinsulate is cheap compared to the MLV so I think I'll stuff that in every crevice I can find. Oh, DEAR......

[ebgs500e]

Originally Posted by michaelahess

Didn't think to do the front floor for some reason. Do you think that made a big difference what with the 1" foam already under the carpet?

Absolutely. The front foot wells done with MLV made the most difference in my case. I did the doors first and did not notice much of a difference in noise. no noticeable Db reduction. What I did notice is better sound quality and higher volume from the factory speakers.

Then I did the front foot wells with the rear seat back and noticed a good difference. This lowered the noise by about 10%. The best way I can describe it is the noise pitch became lower. Prior to doing the foot wells and back seat, the noise was high pitch wine from the tire/road/wind contact. Now it's more of a faded lower pitch version of that.

If you have a smart phone, you may want to down load a noise meter app prior to finishing your project and take some measurements on a specific stretch of road going a specific speed. Then once you are done, repeat the measurements with same conditions to see if you notice a difference. The one I used is literally called "noise meter" for Android. It allows you to make a log of your readings and save several logs to bring up at a latter time.

Did you take any pictures of your project?

[BryanGT]

Originally Posted by ebgs500e

So... 70 MPh is now 58 Db on Asphalt. That is an 8 Db decrease and a very noticeable improvement in noise. I can now speak on the Bluetooth handsfree going highway speeds and the other people actually hear me!!!

So you've halved sound pressure level, and approached a subjective reduction of half too. Not bad at all!

How much do you think all of the material weighed? I would do this but I invariably end up fucking snapping some clip and then it eats at the back of my mind like a cancer.

[ebgs500e]

Originally Posted by BryanGT

So you've halved sound pressure level, and approached a subjective reduction of half too. Not bad at all!

How much do you think all of the material weighed? I would do this but I invariably end up fucking snapping some clip and then it eats at the back of my mind like a cancer.

About 43 Lb total weight added. Mostly from the MLV. As the name implies, it is Mass Loaded Vinyl, so it is heavy stuff. The breakdown in materials is on top of the string.

The key is judicial application of materials if you want to keep the weight down. The wheels/pavement contact generates the most noise, so I focused my attention at blocking off that source. The two front foot wells are right in line with the front wheels. The rear seat bottoms are right in line with the rear wheels. Rear seat back to block off anything coming from the trunk and doors to block sound reflected off of and emitting from other vehicles. No need for roof since nothing coming from there (usually).

As for snapped clips, I had the same phobia, but a pannel removal tool helped that:
[ame="http://www.amazon.com/gp/product/B0002SRCMO/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1"]Lisle 35260 Plastic Fastener Remover : Amazon.com : Automotive[/ame]
Not a single broken clip.

[xjohnx]

Any chance you could list the areas that you feel made the biggest difference in sound, so that those of us who don't want to go all out can get the most bang for our buck by hitting only those areas? Hope that made sense.

[l0aded]

How useful is the 3M thinsulate for soundproofing? The stuff is pretty light and am wondering if it's mainly used for thermal insulation rather than acoustic.

[michaelahess]

Originally Posted by ebgs500e

Did you take any pictures of your project?

My build log, or my photobucket stream I think has some. Can't remember off hand. I know I took photos of it. I'll double check and upload them tomorrow if I haven't yet. www.photobucket.com/mikesbrz

I'll use the rest of my mlv for the front wells. I did the entire trunk as I wanted the sub to be as efficient as possible, so that used a lot. The rear seat has no deadening obviously due to that.

I ordered some of the thinsulate, we'll see how that does. If nothing else it should separate all the bits between panels which should reduce rattles considerably.

[Xdragonxb0i]

where did you buy the MLV from? i think i will do the front footwells

[tracerit]

Gonna check this out this weekend. Thanks for the pictures and guide!