Sound Deadening

Anybody found a successful coating or blanket to cover the rear wheelwells in a 5, capable of being re-covered with the factory panels? I drive mostly with the 2d & 3rd seats removed. Rear tire noise has been an issue all 60K miles, but I now believe the 2d row seats were blocking at least a little bit.

Still no animation here. You're welcome.

There is a thread on the "how to" forum:

http://www.mazdas247.com/forum/showthread.php?123698901-How-To-soundproof-your-Mazda5

Somebody posted a link to this website that has quite a bit of interesting products:

http://www.b-quiet.com/ultimate.html
http://www.sounddeadenershowdown.com/

Read a bit at sounddeadenershowdown.com, he's got a good synopsis of the current best practices for sound deadening a car. It used to be Dynamat, Dynamat, and more Dynamat, now it is targeted use of CLD, and a barrier layer (usually MLV) decoupled from the vehicle structure with CCF.

As a totally coincidental point, that's what I was working on tonight.

Wow! Cool.

So the CLD is the metallic silver tiles that you applied on the first picture?
And the second pic is the barrier layer (MLV = mass loaded vinyl)

How many hours to remove the third row and plastic trim from the back?

Do the 5s get noisier with time / miles?

I can't speak to any possible increase in noise with mileage, my car is a 2013 w/ 15k miles so far. Tires to get significantly louder as they wear.

Yes, the first pic is the CLD (contained layer damper) tiles. There are many brands, the most well-known being Dynamat. They reduce resonance in metal panels, but they are not good at blocking sound waves (like road noise). Current thinking is that more than 25% coverage is unnecessary to achieve good dampening.

In the second pic, the "soft" material that is crumpled up in the spare tire well, and is also behind the MLV on the right quarter, is CCF (closed cell foam). It's only job is to make sure the MLV doesn't touch the metal structure of the vehicle, the CCF itself does nothing to deaden the noise.

The MLV (mass loaded vinyl) is the noise barrier. You use the CCF to decouple the MLV from the metal vehicle structure b/c if the MLV is touching the metal, it is going to vibrate with the metal and transfer sounds. What you are trying to achieve is a limp layer of mass totally decoupled from the noise source, that will both reflect and absorb the sound.

Getting the rear seat and trim pieces out is very easy, maybe 30 minutes? Fitting the MLV is the most time consuming part.

I completely lined the rear area behind the 2nd row with foil backed asphalt. The floor and walls got one layer, the wheel wells got 3 layers. I then filled all voids and crevices with a recycled denim insulation. This took one evening for me to pull the 3rd row and all rear panels, install, and then put everything back in. I did not do the hatch as I didn't want this to get heavier. As said above pulling everything is very quick/easy.

Made a big difference. While seated in the 3rd row on the highway you could not hear those seated in front row unless they raised their voices. Now those in the 3rd row can clearly hear the front row at regular volume. The 3rd row is now also the quietest place to be in the car.

Due to this I also void filled the front door panels. This helped with road noise a bit up front, too and really improved the speaker's treble/mid sound (I was hoping for more bass response, oh well). The front door cards had more insulation on them than I thought they would have:



And for those who are curious, a shot of the door with the panel removed:



I ran out of time, but next time I will pull the inner door panel as well and line the back of the outer door skin. I will do the sliding doors, too. I think this car will benefit greatly from doing the floor as well, but I won't get there until next spring/summer.

torquelover, look into the decoupled MLV sound deadening concept. Especially for the floor, where the install is super simple. The "multiple layers of Dynamat" (or other equivalent product) is the "old" way of thinking in vehicle sound deadening. I know for me, it was all I knew 15 years ago when I was into car audio as a hobby. When I started researching how to quiet down this car last year, I was surprised to find this "new" method. But the science behind it is sound, the anecdotal evidence from everyone who uses it is 100% positive. By all accounts, it is cheaper, lighter, and better performing than the multi-layer Dynamat method.

Damn it. This is giving me bad and unnecessary ideas, again...

For your guys who have done thorough sound deadening, how much of the aero/wind noise do you hear? My grip is there's a lot of glass on this car and it is about as thin as you can get. I was in a new Altama rental and even that car's glass is almost double thickness... the SRX was almost 2.5x thicker. So, will this help drastically??

sac02 said:

torquelover, look into the decoupled MLV sound deadening concept. Especially for the floor, where the install is super simple. The "multiple layers of Dynamat" (or other equivalent product) is the "old" way of thinking in vehicle sound deadening. I know for me, it was all I knew 15 years ago when I was into car audio as a hobby. When I started researching how to quiet down this car last year, I was surprised to find this "new" method. But the science behind it is sound, the anecdotal evidence from everyone who uses it is 100% positive. By all accounts, it is cheaper, lighter, and better performing than the multi-layer Dynamat method.

Click to expand...

I have looked into it, and it does work. Monetarily I spent well under $100 on the material (from a local home improvement store) while only using half of it. Back in the day, this would have been $1k+. I also like the idea of felt lined wheel wells. Check out the rear wheel wells in a new MZ6. The felt is decoupled by being fastened and held away from the wheel well. Pretty neat.

Silentnoise713 said:

Damn it. This is giving me bad and unnecessary ideas, again...

For your guys who have done thorough sound deadening, how much of the aero/wind noise do you hear? My grip is there's a lot of glass on this car and it is about as thin as you can get. I was in a new Altama rental and even that car's glass is almost double thickness... the SRX was almost 2.5x thicker. So, will this help drastically??

Click to expand...

This helped me drastically, however everything is a balance, which is why I decided to do the front doors as well. There is a lot of wind noise in the MZ5 so if you go too far this is all you will hear. Wind noise is harder to eradicate. The body shape, seals, door frame design, and glass thickness can't be easily changed to make it quieter.

I did this as I had a 3.5k mile road trip in the car coming up and the road noise was an issue for me. Getting rid of the terribly loud unevenly worn stock tires and an evening of work transformed the car.

I would rather hear wind rush as it's more of a white noise for me compared to the ringing, booming, thrumming road noise we once had.

Member Vasy did his roof if I recall and reported it was the area of greatest improvement for him.

Good stuff. Thanks.

ROBOTO said:

There is a thread on the "how to" forum:

http://www.mazdas247.com/forum/showthread.php?123698901-How-To-soundproof-your-Mazda5

Somebody posted a link to this website that has quite a bit of interesting products:

http://www.b-quiet.com/ultimate.html
http://www.sounddeadenershowdown.com/

Click to expand...

Torquelover, can you ID the materias brands you used, and generic sources, i.e. bldg supply, auto supply.

torquelover said:

I completely lined the rear area behind the 2nd row with foil backed asphalt. The floor and walls got one layer, the wheel wells got 3 layers. I then filled all voids and crevices with a recycled denim insulation. This took one evening for me to pull the 3rd row and all rear panels, install, and then put everything back in. I did not do the hatch as I didn't want this to get heavier. As said above pulling everything is very quick/easy.

Made a big difference. While seated in the 3rd row on the highway you could not hear those seated in front row unless they raised their voices. Now those in the 3rd row can clearly hear the front row at regular volume. The 3rd row is now also the quietest place to be in the car.

Due to this I also void filled the front door panels. This helped with road noise a bit up front, too and really improved the speaker's treble/mid sound (I was hoping for more bass response, oh well). The front door cards had more insulation on them than I thought they would have:

And for those who are curious, a shot of the door with the panel removed:

I ran out of time, but next time I will pull the inner door panel as well and line the back of the outer door skin. I will do the sliding doors, too. I think this car will benefit greatly from doing the floor as well, but I won't get there until next spring/summer.

Click to expand...

side panels fit

sac02, have you replaced the rear side panels yet? Just wondering about the bulk & thickness of your CCF+MLV layers. Also I appreciated the pix. How did you fasten the layers to the interior sides?

Do you mean have I lined the rear door panels (no I haven't) or have I reinstalled the trim in the rear of the car (yes I have)?

I didn't have any issue getting the panels back on due to the thickness of the CCF and MLV. I used a few various ways to hold the deadening up while working. At the rear of the panel, I brought it up higher on the d-pillar and the upper trim held it in place, as well as ran in behind the rear speaker bracket. Under the window there is an unused weld nut so I used an m6 bolt and washer, and at the front, there was an unused weld stud that I was able to "hang" the MLV on. The most time consuming part was contouring and piecing together the "boxes" on the side of the trunk behind the rear wheel wells.

m5jrw said:

sac02, have you replaced the rear side panels yet? Just wondering about the bulk & thickness of your CCF+MLV layers. Also I appreciated the pix. How did you fasten the layers to the interior sides?

Click to expand...

When I put MLV in our 2006 Mazda5, it was a tight fit. I used MLV with a ~2mm foam pad for decoupling. I had to cut away around some of the pushpins, otherwise they would not fit properly. sac02 has a newer model 5 - he may have more room. I think the 06 and 09 are similar. I'll see if I can dig up some pictures later. I used automotive Velcro strips to hang the MLV - when I took off the doors later, some of the strips had slid off.

yes, I had to cut holes in the MLV around each clip, but that takes seconds and was no issue.

The sounddeadenershowdown.com website really promotes the tactic of using velcro to hang the MLV, but I had the same concerns that you apparently experienced - that the velcro wouldn't stick permanently to either the vehicle or the MLV (the vinyl MLV is notoriously difficult to adhere to - hence the use of contact cement to patch the MLV together). That's why I chose to hang the MLV from studs and unused weldnuts and other permanent vehicle features. I had no issues whatsoever fitting the trim panels in the rear after installing the CCF and MLV.

I have not done the doors yet, but I would not be surprised if they are a tighter fit, doors always have a lot going on in there.

m5jrw said:

Torquelover, can you ID the materias brands you used, and generic sources, i.e. bldg supply, auto supply.

Click to expand...

Home improvement store items:

http://cofair.com/window.aspx

http://www.bondedlogic.com/construction-products/ultratouch-denim-insulation

Last week I started working on the sound deadening, and was able to do a bit more this weekend. I bought materials almost a year ago and had it on my to-do list since forever... Just now getting around to it. :/ I really should have put more priority on getting this done sooner, it really bugs me how damn LOUD this car is (and not in a good engine or exhaust note loud kind of way).

The CLD tiles are RAAMmat, the CCF is ensolite sourced from RAAM, and the MLV I got semi-local at a home theater place.

I'm using 1/2lb MLV instead of the more common 1lb MLV in the interest of weight. It should still be a vast improvement. It will be about a 40-50lb weight penalty, but in this case, for this car (DD) it is worth it - this thing is just a loud, echo-y, road noise-y, tin can.

Here are the CLD tiles in the rear of the car:



The rear panels were a PITA, as they are deeply sculpted and I tried to make them out of a single piece with as little patching as possible. The floor is about 1000 times easier/quicker. I think that even the doors will be quicker because even though they have a lot of wiring to run through them, they are not the deep 3D contours of these rear panels.

Here is the LH rear panel. I chose not to cut/shape the CCF/MLV to go behind the jack. In addition to making life easier by not having to form that pocket, it probably deadens more effectively. In the rare instance that I do get a flat, I will just need to cut through the MLV (can easily be ripped by hand) to get to the jack. Of course, now that I said a flat isn't likely, I'm going to get one next week...



Here is a close-up of how I worked the CCF/MLV behind the rear speaker and CSA:



Here is the trunk section mostly finished:



Yesterday I completed the trunk area, and did the floor up to the rear of the front seats. I still need to do the front of the floor, and all 5 doors.

With the trunk and middle/rear floor compete, the results are interesting. The vehicle doesn't SEEM much quieter at first glance, but the drive home was kind of disorienting because the sound was very different. I do notice a difference in sound level, but maybe not as much as I'd hoped for how much work I put in this weekend - BUT: all the work I did is in the rear of the vehicle. When I poke my head around the headrest and lean back to listen to the rear of the vehicle, it is REALLY quiet.

What I think is going on is that I've made a significant reduction in sound from the rear of the vehicle, but not from the front or doors. When I'm sitting in the front driving, I'm sitting closest to the noisiest parts of the car (FR tires, engine, etc) and that noise is still present 100%. The part of the car that I've deadend is the rear of the car, which is much farther away (remember sound intensity drops with the square of distance) - so despite the fact that the rear is much quieter, it is still dominated by the noisy front of the car. I think the slight disorientation feeling that I mentioned was the fact that I was still hearing lots of road noise (overall levels about 80% of original), but I wasn't hearing anything behind me like I was used to.