Dynamat to the rescue - cabin booming noise reduced

[C-Mack]

Some postings and other places have made mention of a cabin booming or reverb type sound when traveling down the road or when you hit a sharp bump at speed, especially when the cabin/cargo area is empty in the Grenadier. I’ve experienced similar sounds and although not horrifyingly loud for short trips on longer highway drives it seems a bit more annoying.

I’m not a big fan of sticking sound deadening material all over the place but I had a hunch the rear floor in the cargo area was acting as a type of drum and might be contributing to the booming sound. So I put down a single layer of Dynamat Xtreme on the exposed part of the cargo area underneath the rubberized mat. I have the cargo hold down tracks so I removed them first so I could lay the Dynamat down completely flat. I reinstalled the tracks on top of the Dynamat and after the first drive it has made a noticeable difference to the sound quality inside the vehicle.

Needless to say, I was dubious such a thin layer of sound deadening material would make such a difference. It’s even quieted down the exhaust so perhaps the rear muffler was contributing to the booming sound and was vibrating the cargo area floor? I’m by no means a sound deadening expert but I’m rather pleased with the results. The Dynamat is thin enough once the rear cargo mat was reinstalled everything looks like stock so you’d never know any sound deadening material has been added.

I don’t think it would present any issues later on if I was to install a drawer system as with the added bulk and structure it would probably help quiet things down even more assuming the drawer system itself doesn’t rattle around. Here are some pictures for anyone dealing with the same issue.

 

[Greg]

While I never had the booming problem, I did the same as my drawer system will sit on the floor, not the rubberised mat.
It certainly made a difference as the back floor is like a steel drum

 

[C-Mack]

While I never had the booming problem, I did the same as my drawer system will sit on the floor, not the rubberised mat.
It certainly made a difference as the back floor is like a steel drum
View attachment 7878586
View attachment 7878590

Very nicely done… I’m glad I had the same positive results you did. It was actually a fun little job to do and didn’t take very long at all. The Dynamat material was very easy to work with and will most likely install a drawer system in much the same manner as you did.

 

[SkiBum1]

Some postings and other places have made mention of a cabin droning noise or booming sound when traveling down the road at speed especially when the cabin/cargo area is empty in the Grenadier. I’ve experienced similar sounds and although not horrifyingly loud for short trips on longer highway drives it seems a bit more annoying.

I’m not a big fan of sticking sound deadening material all over the place but I had a hunch the rear floor in the cargo area was acting as a type of drum and might be contributing to the booming sound. So I put down a single layer of Dynamat Xtreme just on the exposed part of the cargo area underneath the rubberized mat. I have the cargo hold down tracks so I removed them so I could lay the Dynamat down completely flat. I reinstalled the tracks on top of the Dynamat and after the first drive it has made a notable difference to the sound quality inside the vehicle.

Needless to say, I was dubious such a thin layer of sound deadening material would make such a difference. It’s even quieted down the exhaust so perhaps the rear muffler was contributing to the booming sound and was vibrating the cargo area floor? I’m by no means a sound deading expert but I’m rather pleased with the results. The Dynamat is thin enough once the rear cargo mat was put back in everything looks like stock you’d never know there is any sound deadening material installed.

I don’t think it would present any issues later on if I was to install a drawer system as with the added bulk and structure it would probably help quiet things down even more assuming it doesn’t rattle around. Here are some pictures of the install for anyone dealing with the same issue.

I haven’t noticed a problem with mine, but your solution is really cool!

 

[GN4HIR]

And while those were complete coverage, you can stop the resonating just by adding a couple of sq ft of the material.

 

[grnamin]

Thank you for this thread. Black Friday project...

 

[RobP]

Thank you for this thread. Black Friday project...

Verdict?

 

[grnamin]

Verdict?

Didn't drive after installation. Will report back tomorrow.

 

[grnamin]

There is some attenuation and I think it was worth the effort to install the Dynamat.

 

[parb]

I've decided to do the same. I was going to treat the doors anyway when I install my new speakers

 

[RobP]

I never thought to do this since I haven't experienced any resonance from the rear, until today. I normally have the rear filled with fishing and kayak gear, including a large moving blanket that was doubled up and covered most of the rear floor. I cleaned it all out yesterday since the season is over and on the highway tonight I was thinking what's that booming sound coming from the rear. I'll put the moving blanket back in and confirm, but will probably end up going with dynamat anyway. I think I have some laying around somewhere.

 

[HereinDaRockies]

Some postings and other places have made mention of a cabin booming or reverb type sound when traveling down the road or when you hit a sharp bump at speed, especially when the cabin/cargo area is empty in the Grenadier. I’ve experienced similar sounds and although not horrifyingly loud for short trips on longer highway drives it seems a bit more annoying.

I’m not a big fan of sticking sound deadening material all over the place but I had a hunch the rear floor in the cargo area was acting as a type of drum and might be contributing to the booming sound. So I put down a single layer of Dynamat Xtreme on the exposed part of the cargo area underneath the rubberized mat. I have the cargo hold down tracks so I removed them first so I could lay the Dynamat down completely flat. I reinstalled the tracks on top of the Dynamat and after the first drive it has made a noticeable difference to the sound quality inside the vehicle.

Needless to say, I was dubious such a thin layer of sound deadening material would make such a difference. It’s even quieted down the exhaust so perhaps the rear muffler was contributing to the booming sound and was vibrating the cargo area floor? I’m by no means a sound deadening expert but I’m rather pleased with the results. The Dynamat is thin enough once the rear cargo mat was reinstalled everything looks like stock so you’d never know any sound deadening material has been added.

I don’t think it would present any issues later on if I was to install a drawer system as with the added bulk and structure it would probably help quiet things down even more assuming the drawer system itself doesn’t rattle around. Here are some pictures for anyone dealing with the same issue.

How much of the material do you need to cover the cargo area?

 

[C-Mack]

The Dynamat bulk kit comes with 9 sheets 18”x32” you’ll need at least four of those sheets to cover the exposed floor in the cargo area and a few smaller cut pieces to fill in odd bits here and there.

 

[grnamin]

Did 75 mph on the highway for the first time since installing Dynamat. Cabin was definitely quieter than before.

 

[C-Mack]

Did 75 mph on the highway for the first time since installing Dynamat. Cabin was definitely quieter than before.

By no means is it Rolls Royce quiet but the Dynamat did help take a bit of the edge off the reverb types sounds especially at highways speeds. Worth the time it took to install which really wasn’t all that long. 35 minutes if you slap it down really quick and a couple of hours if you take your time and make it look neat and tidy.

 

[pjsb50]

Did you install the dynamite under the plastic? So that you cannot see it in the back?

 

[C-Mack]

Did you install the dynamite under the plastic? So that you cannot see it in the back?

Yes, on my install I ran it a few inches underneath the removable plastic cover near the door only because I have the cargo rails and wanted to extend the matting far enough it was under the entire length of the rails. Optionally, you can stop the mat at the natural seam in the floor along the forward facing edge of the plastic cover and call it good if you wanted.

 

[grnamin]

Did you install the dynamite under the plastic? So that you cannot see it in the back?

Here's the full extent of my installation so far...

Turns out I didn't have to remove the plastic wheel well covers. No Dynamat under the section below the rear seat backs. I'm thinking of adding more in the blue area.

 

[C-Mack]

Here's the full extent of my installation so far...
View attachment 7879942
Turns out I didn't have to remove the plastic wheel well covers. No Dynamat under the section below the rear seat backs. I'm thinking of adding more in the blue area.

Exactly, you don’t have to remove any trim to install the matting. I ran my matting into the blue area you are thinking about near the edge of the sharp crease where the floor drops down to the section with the drain in it. A little overkill but again I wanted the matting underneath the end of the cargo rails so everything was sitting at the same level along the length of the rails.

 

[HereinDaRockies]

How did yal lift up the plastic cargo cover? Just by force?

Mine has the floor mounted L tracks. However it doesn’t look like the tracks are holding down the plastic cover..