Sound Deadening

This is likely to begin a firestorm.....

Planning a HU and speaker change. Looking into sound deadening aspect of this process.

My research about how much to use is full of conflicting information. The sound mat websites ardently say 100% coverage of the area, but they want to sell product. Sound based websites state 35-60% coverage of the area.

Being on a budget and the mat is expensive I don't want to 100% cover everything. I also am not looking for Rolls Royce feel. Just want to suppress road and wind noise. I'd be happy with a 5-10 dB suppression

My thoughts are floor, doors, roof, rear panel (back wall under slider window). Not touching the firewall, I don't want to tear the dash apart.
So, my questions. What is a functional %age to cover in these areas?

 

Firestorm indeed...

EDIT: to answer your question: to each his own.
I completely covered the rear wall (Access Cab), the front doors received maybe 70% coverage, and the rear doors about 60%.
If I ever pull down the headliner I will completely cover the ceiling.
I used Dynamat.

 

Maybe I should've waited until Friday...............

I'm not asking who makes the "best" mat. All the mats are made of similar material.

 

That's good because I have no idea who makes the best stuff. Everybody has their own opinion.

 

Agreed. I can make my own decision on the "best" mat for my $$. Then my opinion can be formed after install and butt dyno of the results.

On your install, do you think you covered too much, not enough? Did you tackle the floor? Do you feel you need more areas covered? Yeah, the headliner seems a bit ticky to me also.

Also Access Cab, specifically '06 V6 4WD.

 

The most bang for my buck was covering the rear wall. I covered 100% and got decent coverage on the lower raised section where the rear seats used to be. I covered down around the jack storage across the rear. I also installed a second layer of a foam deadening material (also made by Dynamic Control) across the rear wall between the ribs. You can see some of that work here:
https://www.tacomaworld.com/threads/the-lawl-team-ullie-express-build.667475/page-13#post-23443399

I installed less coverage on the doors but am happy to say that it made a big difference. When I close the doors they sound solid. I think that most of the exterior noise I hear now comes through the thin glass.

I hope this helps.

 

Thanks. Yes, that helps.

It makes sense that most of the "noise" is from the rear wall. It is closest to primary noise sources, exhaust, tranny, xfer case, rear tires..... I was thinking floor and/or rear wall would be the best targets for suppression.

My coverage plan is forming.
90+% rear wall
50-60% doors
Floor???
Roof???

I hesitate on this because stripping the interior can open a big can of worms for disassembly/assembly. In my past experience, the parts don't quite match up on reassembly, leading to a shitty looking install.

 

Yeah, I understand the concern. I would pull the interior without reservation to cover the floor.
The ceiling is another matter. If the headliner doesn't go back in just right, I will see the "difference" every time I get in the truck.

 

I did doors and rear wall. Didn't want to tackle floor and headliner. Doors definitely sound more solid with the mat installed.

 

Another question regarding the floor.

Would it be possible to lift one side at a time? Follow me...... remove driver's seat, rear "seat", flip the carpet up over the passenger side, install the mat, reinstall all the parts. Then repeat on the passenger side.

I figure this would maintain carpet alignment with all the bits easing reassembly.

Essentially, do the floor in sections.

 

Earlier this year I sound deadened my truck with results that I’m happy with. I confronted all areas besides the firewall (which is up next)

1st layer: Butyl backed sheets, 80% coverage, a couple places with only 60%

2nd layer: Closed cell foam with an adhesive backing, about the same on coverage. This is supposed to create a nice environment for your 3rd layer to soak up most of the actual sound waves entering the cab.

3rd layer: 1lb Mass Loaded Vinyl. Try for 100% coverage here. Sound will leak around the vinyl but it really won’t penetrate it. The mat is dense and difficult to work with if going against gravity. Above the headliner was frustrating but the floor was a piece of cake.

to make all my interior parts fit well again I used one of these cool little tools. Just go along the edges of your plastic pieces and remember that it’s best to go slow and test fit multiple times.

Deburring Tool Kit 11 pcs High-Speed Steel Rotary Burr Removal Blades, Burr Remover Hand Tool for Wood, Aluminum, Copper and Plastic

https://www.amazon.com/Deburring-High-Speed-Removal-Remover-Aluminum/dp/B08BCSFHS6/ref=mp_s_a_1_2_sspa?_encoding=UTF8&c=ts&dchild=1&keywords=Deburring+Cutters&qid=1606580408&s=industrial&sr=1-2-spons&ts_id=340035011&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEySFhaSk1UVEhRUUdGJmVuY3J5cHRlZElkPUEwNjc2NjAzMkhXM1YxT0xXR1lFWiZlbmNyeXB0ZWRBZElkPUEwNjgzODYzMTQ1RTlQOEZBMlBVTiZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

Second Skin Damplifier Pro- thick extruded butyl with thick aluminum- use less than half% coverage only on the big flat areas. You need more than just a pack of this or that, you will get the best results from using a 2- or 3- layer setup consisting of Different materials as in post #11. With that said my first layer (SSDP) certainly made a difference, but it doesn't sound like a Mercedes yet.

 

LOL good luck! That’s a HUGE number.

Keep in mind the butyl sheets are for reducing flex in panels, not blocking noise from outside. Also, they are very heavy so going nutso will add a couple hundred pounds to your vehicle.

Like Lil Puke did, you’ll need actual noise insulation to reduce road noise. Usually it’s thick so fitting panels back together can be challenging.

 

Yeah....I know its a big reduction.

Using my calibrated ear.....its more likely to be in the <3 dB range.

 

Just finished three layer (noico butyl, noico foam, second skin MLV) on doors, floors and back. It is not difficult, but it takes lots of time and planning to do a decent job. One take away, the second skin default 24 inch width luxury liner fits pretty much perfect on the floors of 3rd gen Tacomas. The foam backed luxury liner pro fits perfect on the back wall of the cab (24" x 54"). I am not associated with the company.

Here is a photo of the back:




The luxury liner pro fits so well that I decided not to re-install that stupid plastic monstrosity behind the seats. It scuffs a bit, but so what. I had to do a bit of cutting on the plastic corner material, where it joins the foam-backed vinyl, but I don't think it is too bad. I am sure others would do a better job.

One of the floor:



Four 2 x 4.5 sheets of MLV cover the whole floor. I used one for the front footwells (driver's side is a bit longer). Two sheets yielded the back footwells, with the extensions by the doors. The leftovers fit right in the underseat jack cubby. There was 12 inches on each sheet remaining that I used to join the two sides of each footwell. You can see the join in the photo. I used vinyl glue (does not work well and is super toxic).

A final sheet was on standby when I made a mistake, but I ended up adding it on the back deck, behind and under the rear seats, with about 7 inches of material to spare.

Tricks: Templates! If I had it to do over again, I would use clear plastic, like a thick painter's tarp. You can see through it and then transfer every cut to the vinyl. Also, the front seat rear post spacers came in handy, since they lifted the front seats just about exactly clear of the added volume of three sound deadening layers. I ripped out the cheap jute material on the back of the floor carpet. This probably should have stayed, since the vinyl is hard and a bit unforgiving under the carpet. You can kind of feel the hot air vents under driver and passenger's carpeting. I will probably go back eventually and add some closed cell foam or something to address this.

Any suggestions or advice would be much appreciated. I am a noob at all this.

 

I’d recommend rolling the seats and carpet out and throwing down a layer of Mass Loaded Vinyl. You’ll hear it get called MLV. It’s a dense rubber-like sheet that offers some protection, is waterproof, and has great noise canceling qualities. The only trick to it is that for it to work well, you have to keep the sheets very intact. Only necessary holes such as those for seats and anchoring seat belts should be made. Wherever there’s a hole, sound can leak through. It’s an extremely helpful layer for noise reduction though.

 

Damping material works by damping the material/metal that is not covered with the material. 25% of an area is sufficient. More than that gets into diminishing returns. The best way to demonstrate this is by "The Cymbal Test."

Cymbal Test:
https://www.youtube.com/watch?v=tMzarz4kKJA

 

https://acousticalsolutions.com/mass-loaded-vinyl-and-the-correct-uses-for-it/

Good info on MLV and how it works against sound (it's based on building construction but still good info)

My understanding is use the mat to take away vibration than MLV to help remove the remaining sound.

Cymbal shows a little goes a long way.

I'll be traveling this road soon and hoping for a quieter ride.

 

Bingo! My interpretation, partially from experience is the butyl based layer does a great job of panel dampening and then the closed cell foam gives a great buffer surface for the MLV to work its magic.

I have a buddy doing a 4bt build. He said that a product called Green Slime? Or something similar to that is what a lot of people swear by on the firewall. I haven’t researched it but I plan to eventually.. food for thought at least.

 

I did Noico dampener at around 50% coverage for all 4 doors. Definitely more solid sounding now.

There's 3 layers:

CLD: constrained layer dampener (I think) (Noico dampener) which absorbs vibrations from the material it covers (door skin). 25% coverage minimum, based ony reading.

CCF: closed cell foam which acts as an interface absorber or something for your 3rd layer. I think the idea here is to keep the 3rd layer isolated from other moving/vibrating things not handled by the CLD. 100% coverage. I got some 1/16" neoprene sheets from Foam Factory: https://www.thefoamfactory.com/closedcellfoam/neoprene.html. Plan is to sandwich the MLV with them.

MLV: mass loaded vinyl. 1lb/sq ft seems to be popular. I believe this is where true noise reduction comes from. It acts as a physical barrier to incoming sound waves. Mate it with the CCF to prevent direct contact with moving/vibrating things. 100% coverage. Haven't bought this yet. It's the most expensive.

Floor is tight but I think it should fit all 3 layers. Headliner won't support all. I think you can do CLD & MLV or maybe just one.

Check out this thread. Very helpful. https://www.tacomaworld.com/threads/how-much-sound-deadening-and-proofing-material-do-i-need.660844/