Anyone Sound Deaden?

truck_newbie · March 3, 2020

I was doing some random browsing and it landed me unto Dynamat and sound deadening in general. It got me thinking that maybe it could be the solution to some minor issues I’m experiencing. The T1 is already a very quiet vehicle but some minor issues I can think of that this could fix:

1. Door and interior rattles from Bose speakers. I know a few here find this annoying, me included.

2. Road noise reduction. Houston has a lot of concrete roads and they are much louder than asphalt.

3. Exhaust drone or intrusion, big or small.

4. Any general noises from the truck that don’t necessarily need “repair” but you would rather not hear them e.g: 6.2 squeaks, axle jingling, etc.

I am considering it as a last resort if some minor noises that I’m experiencing can’t be identified and fixed by the dealer. Dynamat is sort of expensive but looks like there are cheaper alternatives that are equally as good.

Anyways, I did a search and couldn’t find any references to sound deadening on the T1. Anyone done this or considered doing this? Please spare me “it’s a truck” comments .

OnTheReel · March 3, 2020

Door panels are on the list for me this spring. Plan is to pull off the white sound deadening pad, dynamat most of back of the door panel, put the white pad back on and see what that does. Also bought a roll of felt tape to *maybe* put on some of the mating surfaces of the door panel and trim. Still uncertain where that will come into play having not had it apart yet.

The rattle on mine seems contained to the armrest, and the area of fake leather above it. It really drives me nuts on certain songs and it’s a shame because the stereo otherwise sounds pretty good to me. My thoughts on doing the panel instead of the door is to hopefully block some of the resonance and “stabilize“ the panel.

Looking at the backside, there seems to be room for improvement on the factory deadening.

The rest of the truck...to me...seems past the point of diminishing returns on dynamat-ing.

truck_newbie · March 3, 2020

30 minutes ago, OnTheReel said:

Door panels are on the list for me this spring. Plan is to pull off the white sound deadening pad, dynamat most of back of the door panel, put the white pad back on and see what that does. Also bought a roll of felt tape to *maybe* put on some of the mating surfaces of the door panel and trim. Still uncertain where that will come into play having not had it apart yet.

The rattle on mine seems contained to the armrest, and the area of fake leather above it. It really drives me nuts on certain songs and it’s a shame because the stereo otherwise sounds pretty good to me. My thoughts on doing the panel instead of the door is to hopefully block some of the resonance and “stabilize“ the panel.

Looking at the backside, there seems to be room for improvement on the factory deadening.

The rest of the truck...to me...seems past the point of diminishing returns on dynamat-ing.

Looks like you are much farther along this path than me. Like you, I'm maybe part of the few that actually likes the sound of the Bose system but the occasional rattles with some songs can get annoying. I thought the oem kicker sub upgrade would solve it but it didn't (sounds good though).

Most of the research i have done so far suggest doing the doors and floor. I will also most likely just start with the doors, see the effect and decide where to go from there.

You might not need to do the whole back side of the door. One of the videos i watched, i think the guy just applied a small piece behind the speaker. He did the "knock test" and it was quite impressive the difference from just a small piece.

Dynamat Door Install Video

OnTheReel · March 8, 2020

Had some down time today and did the driver’s side...holy cow...what a difference! I seriously picked up so much bass I turned it down from 10 on the EQ to 6...it was too much on Hits 1 station! Rattling is about 90% gone, nothing like before. And the door closes with more of a thud too!

Pulling the panel off, I noticed the door is actually surprisingly well dampened. There are a few side impact bars that run through the door and the door skin is foamed onto the bars. Everything felt really tight and made a solid thud when I tapped it, not tinny sounding.

The main shortcoming I noticed was the vapor barrier. It’s an “acoustic“ type foam, but it was adhered very loosely and is thinly constructed. Tapping the speaker cone induced some rattles because the center of the barrier was not glued to the support bars going across the opening in the door. This would most definitely make some noise and kill some bass.

Somewhat of a plan in hand, I started sticking Dynamat on the back of the door panel for starters, focusing on the armrest area that rattled a lot on mine. But also put strips anywhere that sounded plasticy when I tapped it. All told, added about 1 pound of Dynamat to the panel. To wrap it up, I removed all of the push pin clips that hold the panel to the door. I put a small piece of Tesa tape where the clip slides in, slit it, and put the clip back. That takes up any slack in between the clip and the panel. Then I put the factory white pillow sound deadener back over top and the panel was done.

On the door itself, I pulled the speaker, put some Dynamat behind it and some behind the vapor barrier. Didn’t go overboard because I have a limited amount of Dynamat, and didn’t feel like it needed much. Wrapped the clip and tongue of the speaker module in Tesa tape and threw it back in.

Next, I glued the vapor barrier correctly (paying attention to the braces that weren’t glued to it before). Then I just put Dynamat over the barrier to beef it up. I didn’t overlap to the door, so the vapor barrier can be removed for service as easy as if it were factory stock. I forgot to take pics but still have one door to go. I am betting this made the biggest difference. Now, I know a pro would ditch the barrier and go over the whole door, but that was not practical for me to do, especially if the window motor craps out! After slapping the Dynamat on, the barrier sounded like wood when you tap it, so I think it’s doing the job great now! Very sturdy.

To re-assemble, I snapped the door panel back on carefully. I also applied Tesa tape around all of the clips holding the fake wood trim piece on, as well as a few wraps where it’s tongue slides into the arm rest. All told, took about an hour and a half, just putzing around and engineering things as I went.

This is my materials list thus far. Fabric tape:

Tesa 51608, 25m x 19mm adhesive wiring cloth tape original ISOBAND 3 pcs pack https://www.amazon.com/dp/B00XPDVER2/ref=cm_sw_r_cp_apip_wT2o1Qb52Dd1E

Tape for vapor barrier:

Yunpo Butyl Sealant Tape 4M/13Ft Waterproof Butyl Rubber Sealant for Car Headlamps Window Door Windshield Butyl Tape Black https://www.amazon.com/dp/B07PRXRF9D/ref=cm_sw_r_cp_api_i_pvdzEb56GKEMZ

Dynamat:

Dynamat 10435 12" x 36" x 0.067" Thick Self-Adhesive Sound Deadener with Xtreme Door Kit https://www.amazon.com/dp/B00020CAUG/ref=cm_sw_r_cp_api_i_1XdzEbSRG0BRQ

Not listed are trim removal tools, 7mm socket, wife’s wallpaper roller, etc.

Overall, bang for the buck here is just awesome. I was really, really surprised.

truck_newbie · March 8, 2020

That's awesome man. Great minds think alike . Got a kit myself over the week. Went with Kilmat. Also have my Zoom H4n and dB Meter to do some pre and post measurements. I was planning to start the install this weekend but will probably start next week. I instead did some pre measurements today using Zoom H4n and the dB Meter so i'll have something to compare to once done.

I'm really glad you are liking the improvements. I had no doubt there would be improvements after deadening the doors. I'm reconsidering doing the inner-door layer or doing too much because of potential future PDRs. I did at least get one thing deadened today though. These 2 screw covers go over the front passenger side grab handle. I had to remove them when routing my dashcam wiring and they have been rattling ever since. Today i stuck 2 kilmat stickers on the backside of both of them and the rattling has been eliminated. I'm really looking forward to doing the doors and other areas.

OnTheReel · March 8, 2020

That’s great you are going to measure the difference...will be nice to see it on paper.

Think you’ll be just fine putting minimal, if any material on the door skin. I guess I pictured that the door would be flimsy, rattle-y aluminum but that’s just not the case. It’s all very sturdy feeling on the skin side. And then the inner door has a lot of rolled edges, dimples, ribs, etc. I really think the main thing letting it down was the vapor barrier flapping in the breeze down there.

truck_newbie · March 8, 2020

That's good to know, will keep that in mind when i take the door apart. I will be deadening the floors a little bit, just one rectangular mat under each passenger. When the kicker sub really gets going, i can feel the vibrations through the floor. Hoping deadening the floors should reduce it a little bit. Any reduction in road noise that comes from that will be a side benefit.

I don't expect to measure much difference before and after but if i feel like i'm hearing a difference, i would rather it not just be a placebo effect. We will see how it goes.

OnTheReel · March 9, 2020

8 hours ago, truck_newbie said:

That's good to know, will keep that in mind when i take the door apart. I will be deadening the floors a little bit, just one rectangular mat under each passenger. When the kicker sub really gets going, i can feel the vibrations through the floor. Hoping deadening the floors should reduce it a little bit. Any reduction in road noise that comes from that will be a side benefit.

I don't expect to measure much difference before and after but if i feel like i'm hearing a difference, i would rather it not just be a placebo effect. We will see how it goes.

Yeah, I’m mainly happy to have gotten rid of the buzzing door panel, but you may be surprised at the overall result. I know I am.

truck_newbie · April 13, 2020

Finally got around to doing this. Installed some deadening over the weekend. Did front doors and a bit of the floors. Only left with the rear doors, will do that later.

Disclaimer: I make no claims of being an expert on this. Audio engineering tends to have a lot of controversial topics so I’ll try not to step on any landmine.

TL;DR -> You should do this. Best way I can describe the improvement is the sound system sounds very clean. It’s actually a little bit weird. I can really crank it up with no rattling or resonance from the doors and the bass sounds very tight and less boomy. You don’t have to do any measurements like I did, just stick away and enjoy. Keep wanting to go out for a drive it so I can listen to it.

@OnTheReel, good tip on the fabric tape, definitely made the clips tighter. Didn’t end up using the butyl tape though, the vapor shield on mine was still sticky for re-application.

Summary

1. I took measurements before and after with the UMIK-1 and REW software. I didn’t do any tweaks to the system. Just wanted to see before and after performance from installing the mats. Will probably tweak and dial the system in later.

2. Frequency response didn’t show much variation pre and post install.

a. I didn’t see any improvement in the mids which was a little disappointing. Nevertheless, resonance improvement won’t show up in frequency response anyways.

b. Freq response results tells me my system is unbalanced and that I like a lot of bass . Don’t judge. I actually found that a little surprising as the kicker knob is only halfway and my settings are bass=2, mid=4, treble=4.

3. Spectrogram measurements show that post install, the bass decays faster. You can see in the pre-install that the bass has some decent magnitudes even past 600ms. Much tighter now.

4. Material is not expensive and it’s very easy to apply.

a. The doors are not hard to take apart. Some of the clips are stubborn but they should come off with a little persuasion.

b. I’m not sure how much improvement came from doing the floors but they are the easiest to apply. You just lift the carpet and roll it on. It definitely killed some of the Kicker sub vibrations that travel through the floor. I think it’s maybe a tad quieter now but I haven’t measured the noise SPL post install so can’t say for sure. Will measure it later.

5. Knock test didn’t disappoint and the door has a much more solid thunk to it when closing.

6. Surprisingly there is actually some factory applied sound deadening. I have highlighted it below. There is a deadening mat that goes across the top section of each of the front doors applied from factory. Who would have guessed.