School me on sound deadener

[calokie]

Apologies to the OP for asking a side question.... I have a 97 on 33" geolander MTs. I do hear them but nothing crazy, Question is why do 80 owners gut their rigs and apply sound deadening material? I understand why but is it mainly for heat or for sound, as previously mentioned my 97 doesn't seem loud inside, maybe I'm just used to my old 82 pickup??? (I have owned my 80 for almost a year but not much traveling yet)

 

[Outsane]

To silence outside sound... the quetier the more comfortable, also to make it easier to have conversations on long trips with the kids in the back seat. I probably won't get Mudd terrains next time, impulse I wanna get on the Rubicon buy.

 

[Somebodyelse5]

Apologies to the OP for asking a side question.... I have a 97 on 33" geolander MTs. I do hear them but nothing crazy, Question is why do 80 owners gut their rigs and apply sound deadening material? I understand why but is it mainly for heat or for sound, as previously mentioned my 97 doesn't seem loud inside, maybe I'm just used to my old 82 pickup??? (I have owned my 80 for almost a year but not much traveling yet)

Because we are bougie and like the quiet

 

[Boykin Hollow]

What I have found for me and so far it works really good and by far the cheapest way out if just to cut the radio up a little louder. Works every time !!!!!!!!!!!

 

[calokie]

What I have found for me and so far it works really good and by far the cheapest way out if just to cut the radio up a little louder. Works every time !!!!!!!!!!!

This is typically what I do, being a Judas Preist/Anthrax and Maiden fan could be my advantage at least for covering up road noise

 

[NLXTACY]

I used the peel and seal (home depot stuff) in my old 82 pickup, although it does work it makes the truck smell indefinitely

Only because you didn’t seal the edges

 

[Delta VS]

1. ISO-butyl rubber (roofing material) WILL off gas UNLESS you seal all the edges with aluminum tape. Did that in my 60 and zero smell and huge sound difference.

My LX and customer rigs I only use Dynamat. This is mainly has a matter of resale. Dynamat sounds a lot better than “Random rebadged butyl”.

2. There is ZERO need to remove the OEM asphalt. None. It’s a sound deadener. Ok, wait…caveat: I DID remove with dry ice because I was driving without a carpet for so long and the heat of SoCal just turned it to mush around the trans tunnel. I wanted it gone.

You absolutely don’t need to cover every single inch. 25% coverage takes care of it. But it looks so incomplete and I’d just never hand that to a custoner.

The Dynamat/Hushmat/Fatmat/etc is the first step. The biggest sound reducer is the MLV (mass loaded vinyl) layer with foam on both sides.

Definitely remove all of the old jute. I use a wire wheel on a drill and it pulls that all right off. You need sticky to stick, ya know.

Buy yourself a roller and spare your hands.

3. Use a foam hole cutter for the bolt holes. Saves so much time.

1. The nice thing I like about Hushmat in particular, is the thicker piece of aluminum that is on the non-sticky side. Stabilizes it a bit. Plus, Hushmat is the easiest stuff I've used to date, in terms of application. and the stickiest.

2. Completely disagree on this front. Have done some tests and even when it's been cleaned really well, have not had good luck with the new stuff sticking to it.

3. That is a great idea

 

[Somebodyelse5]

1. The nice thing I like about Hushmat in particular, is the thicker piece of aluminum that is on the non-sticky side. Stabilizes it a bit. Plus, Hushmat is the easiest stuff I've used to date, in terms of application. and the stickiest.

2. Completely disagree on this front. Have done some tests and even when it's been cleaned really well, have not had good luck with the new stuff sticking to it.

3. That is a great idea

2. You seem to be the only person having this issue. Did you clean it really well, use isopropyl? Tape the seams? Roll it on?

 

[gummycarbs]

I want to start with the area under the rear carpet and the rear quarter panels to try and mitigate my exhaust.

I've been running around without my rear interior trim for quite awhile, as I slowly built my drawers and custom rear side panels and subwoofer box & mount.

I put Noico sounds deadener on all the exterior sheet metal in the vehicle. I didn't apply it over any factory mass-loading except where I didn't think the factory used enough, like the quarter panels.

*By far* the greatest reduction in noise from the rear came when I put in a couple of layers of Thinsulate SMx00L. I used either the 200 or 300. The rear quarter panels are a big echo chamber for road noise, plus there are holes in the bottom sections for wiring and drainage, and the upper section has the air vents.

The three parts of noise reduction are:
* Mass loading to shift the resonant frequency lower so that it's less noticeable. Classic DynaMat, Noico, etc.
* Absorption of sound by converting it into heat. This is done by the factory by using jute above the headliner and under the carpet.
* Blocking of sound. This is done at the factory by seam-sealing body panels and, to a lesser extent, the plastic interior trim panels. Pull out your rear quarter panel trim and hit the freeway, and you'll see that they do block a surprising amount of noise.

Personally, like I said, I put Noico sound deadener on all the exterior body panels, focusing on the ones with little to no factory mass loading. Then I put down closed cell carpet underlayment foam on the floor (Noico's foam is probably a nice option here), and SMx00L on the vertical or overhead surfaces for sound absorption. Then mass loaded vinyl from McMaster for sound blocking, with either vinyl glue or aluminum tape to seal the sections together. Then the carpet.

A lot of people lean too much into the mass loading, in my opinion. They start putting it over the entirety of every panel, and they start using it as a sealer. That said, when I do the doors, I toss the translucent plastic sheet and replace it with sound deadener. It would be ideal to have a proper mass-loaded vinyl layer sandwiched between foam, but there just isn't enough room.

 

[NLXTACY]

2. You seem to be the only person having this issue. Did you clean it really well, use isopropyl? Tape the seams? Roll it on?

My thoughts as well

 

[solidfrontaxle]

How much Dynamat is required to do close to 100% of an 80?

 

[leonard_nemoy]

What about installing a quieter muffler?

This was my first idea but the rig had a complete new exhaust installed by the previous owner. Full stainless to the cat including the headers. I just can't justify spending the money to remove a perfectly good new muffler when there is nothing wrong with it other than the noise.

 

[leonard_nemoy]

Thanks for all the suggestions and info. I am not very concerned about most road noises or trying to regulate temperatures. I just want to mellow out the exhaust note for longer interstate drives, especially with passengers who don't want to listen to a cranked stereo all day.

I already have the rear quarter panels torn apart so I think I am going to order this hushmat and just hit the rear quarter panels.

This is the hushmat I am thinking of ordering.

https://hushmat.com/products/under-carpet-floor-kit-1-2in-silencer-megabond-thermal-insulating-and-sound-absorbing-self-adhesive-foam-2-sheets-23inx36in-ea-11-5-sq-f

What do you guys think? Fyi my exhaust tailpipe currently ends right under the passenger rear quarter panel.


I will try to record the sound levels before and after the hushmat if I go this route. If my exhaust is still too loud than I will take it to an exhaust shop and see if I can get the tailpipe extended beyond the body.

Thanks again

 

[mudgudgeon]

I have to say, I don't understand this personally. The sound is part of the fun! It's also useful on trails to be able to hear the bangs and scratches, that's useful feedback. And if I get my footwells full of water crossing a stream, that sound deadening looks like it'd do a great job at trapping moisture and promoting rust.

I'm guessing I'm not the target audience for this product though.

It helps cut the drone from mud tires at highway speeds, the drone from exhaust, engine noise, and wind noise.
You still hear plenty of noise.
On a long journey, it can reduce fatigue IMO.

Having worked in noisy environments all my life, I find unnecessary noise tiring and draining.

It also cuts heat radiation into the cab.

Overall makes the rig more comfortable, more enjoyable.

 

[mudgudgeon]

This was my first idea but the rig had a complete new exhaust installed by the previous owner. Full stainless to the cat including the headers. I just can't justify spending the money to remove a perfectly good new muffler when there is nothing wrong with it other than the noise.

All else being equal, stainless steel exhaust is noisier than steel. It resonates and vibrates differently and at a higher pitch

I think extending your tail pipe would possibly help

 

[dogcruiser]

@leonard_nemoy keep us posted. I'll be taking out my dash soon and researching the best heat/noise options for the firewall.

 

[SHIfTHEAD]

I've been running around without my rear interior trim for quite awhile, as I slowly built my drawers and custom rear side panels and subwoofer box & mount.

I put Noico sounds deadener on all the exterior sheet metal in the vehicle. I didn't apply it over any factory mass-loading except where I didn't think the factory used enough, like the quarter panels.

*By far* the greatest reduction in noise from the rear came when I put in a couple of layers of Thinsulate SMx00L. I used either the 200 or 300. The rear quarter panels are a big echo chamber for road noise, plus there are holes in the bottom sections for wiring and drainage, and the upper section has the air vents.

The three parts of noise reduction are:
* Mass loading to shift the resonant frequency lower so that it's less noticeable. Classic DynaMat, Noico, etc.
* Absorption of sound by converting it into heat. This is done by the factory by using jute above the headliner and under the carpet.
* Blocking of sound. This is done at the factory by seam-sealing body panels and, to a lesser extent, the plastic interior trim panels. Pull out your rear quarter panel trim and hit the freeway, and you'll see that they do block a surprising amount of noise.

Personally, like I said, I put Noico sound deadener on all the exterior body panels, focusing on the ones with little to no factory mass loading. Then I put down closed cell carpet underlayment foam on the floor (Noico's foam is probably a nice option here), and SMx00L on the vertical or overhead surfaces for sound absorption. Then mass loaded vinyl from McMaster for sound blocking, with either vinyl glue or aluminum tape to seal the sections together. Then the carpet.

A lot of people lean too much into the mass loading, in my opinion. They start putting it over the entirety of every panel, and they start using it as a sealer. That said, when I do the doors, I toss the translucent plastic sheet and replace it with sound deadener. It would be ideal to have a proper mass-loaded vinyl layer sandwiched between foam, but there just isn't enough room.

I'm getting ready to do this on mine as well and wanted to ask about the comment you made about the biggest improvement you found. When you installed the Thinsulate, did you first add the Butyl mat to the quarter panels and then glue on the Thinsulate? And I can only find SM600L on Amazon. Can you send a link to the stuff you used?

 

[bicycleagent003]

I'm curious about the temperature regulation benefits. My dark blue rig feels like an oven in the summer, especially in the SoCal desert. If I drop the headliner (that seems like a lot of work) and put some mat on the underside of the roof, will it make an appreciable difference? What type of mat, how much coverage for this purpose, and how much of a difference?
Thanks.

 

[mudgudgeon]

I'm curious about the temperature regulation benefits. My dark blue rig feels like an oven in the summer, especially in the SoCal desert. If I drop the headliner (that seems like a lot of work) and put some mat on the underside of the roof, will it make an appreciable difference? What type of mat, how much coverage for this purpose, and how much of a difference?
Thanks.

Absolutely.

I did this in my 105 series.

Clean all the old jute fibre crap off. Use a layer of dynamat (use a small roller to make sure its press bonded on fully, coz its upside down).
Then I used a ¼ layer of med/high density eva foam with a foil layer on one side to cover as much as possible of the roof area without integrity with reinstall of the hoodliner.
Glued the eva to the foil layer on the dynamat.
Tape all joints, gaps, cuts with foil HVAC tape.

It made a noticeable difference in overall cabin noise, and cut the heat on hot summer days.

Edit

I used theceva foam as it was a insulation product used as a thermal barrier behind metal wall siding on a warehouse project. Cost me nada.
It had a decent R-rating, can't remember the details though

 

[bicycleagent003]

Absolutely.

I did this in my 105 series.

Clean all the old jute fibre crap off. Use a layer of dynamat (use a small roller to make sure its press bonded on fully, coz its upside down).
Then I used a ¼ layer of med/high density eva foam with a foil layer on one side to cover as much as possible of the roof area without integrity with reinstall of the hoodliner.
Glued the eva to the foil layer on the dynamat.
Tape all joints, gaps, cuts with foil HVAC tape.

It made a noticeable difference in overall cabin noise, and cut the heat on hot summer days.

Edit

I used theceva foam as it was a insulation product used as a thermal barrier behind metal wall siding on a warehouse project. Cost me nada.
It had a decent R-rating, can't remember the details though

Much appreciated, and thank you for the detailed reply. I don't know anything about this stuff, so forgive me for asking this. You said that your second layer as an eva foam with foil on one side - does it matter which side has the foil? Is the foil always opposite the sticky side? Thanks again.