Highway with rougher finish? In Holland? Roads here are like silk
I will do my best.

But be aware, the sound readings will be depending on:
- type of engine
- type of road surface (texture; we have sound absorbing texture)
- speed
- type of tires (much)
- type of car (mirrors ; new model)

 

Given it probably doesn't have much draw, can't you use an A,C, inverter for that preamp? I've got one for a laptop that plugs into the 12 volt outlet (cigarette lighter slot).

 

We have a pro on the forum - That would be very useful & yes please measure on a rough tar piece of road that kicks up a lot of tyre noise.

 

Just returned from a drive on ashpalt and concrete suburban streets and a concrete highway, up to 70mph. Sound system was off the entire time, windows up, ATC was on Auto set to 70 with a 72 degree ambient. The results are very good. My previous employer used a 10 point expert rating scale for qualitative assessment, and this upgrade would merit at least a full one point improvement (which is significant) . I would call it a noticeable improvement which most customers would recognize. The other side of this coin is that this is an area where the MB NVH engineers should have triumphed over the Program Managers' cost reduction efforts. My educated guess is that it was discussed.

The exhaust noise is significantly reduced. Although tire noise is noticeable as the next in sequence to be heard once other noises are lessened, I have the impression that the tire noise is actually reduced as well. I might guess that the spare tire well was either a conduit or amplifier for tire noise. The same seems to be true for the reduced road noise (tire slap/impact sounds versus tread-generated sound).

I realize that Azn300 did a very good job of managing expectations and not overselling the benefit. And, perhaps, I am just sensitive to small differences, but this is a very worthwhile mod in my judgement. The car has a overall quieter and (this is a difficult perception to quantify) more "solid" feel.

So, start cutting and applying the Damplifier Pro, everyone......and after hanging over that trunk opening for four or so hours...have the heating pad ready for your lower back the next morning!

 

Excellent! Thanks for the report. Now I just need to find someone to apply both layers, of this product as my lower back has about as much metal as our trunks have!

 

Sportstick

Good news! Damping does make a big difference to ones perception of solidity.

Do you believe that continuing this activity to include the wheel arches would be worthwhile?

 

Tread noise is clearly the next target, if one felt not yet satisfied with the under-trunk modification. The choices would be dampening the well or a tire quieter than my Michelin Pilot Sport A/S. Looking at the well from the trunk and observing the rear H-point to spindle, it seems this would be a very intrusive project, involving de-trimming from the rear seat and trunk areas, unless you were proposing some type of spray-on to the exterior surface in the well.

Of course, we are adding the pounds/kilos, which is the number one enemy of fuel economy and performance. And, if tread is the source, there are always those pesky front wheels!

I suggest starting with the full under-trunk area, as I did and see how satisfied you are.

 

laguna,

Did you ever get a chance to measure the road noise in your car?

 

What about using Spectrum instead of Damplifier Pro and Luxury Liner Pro. Would using spectrum alone work better than using the first two products?


Also what's the difference between the following:

Spectrum

Spectrum Sludge

 

i installed damplifier pro second skin, took 2 hours, and i did about 1/2 as complete job as Sportstick did above. added it all around wheel well and in the truck compartments (on the metal) and all around the metal, buttom of the rear bass shelf.

even 1/2 the job (didn't cover the entire surfaces, not a perfectionist) dramatically improved noise reduction (can't hear the road) and sound system improvements. Now i hear the noises/rattles that the road sound used to drown out. i don't care! well i do i fixed those few rattles and now its solid as a rock.

 

Agree with boycjo2, used FatMat, cheaper, maybe not as good, works OK.

There is actually a sound absorbing rubber mat sandwiched in the rear shelf.

AFTER the trunk, first the rear doors then the front doors. Some recommend under the rear seat also and behind the rear seat back (on non-fold down seats). Just be careful of the YAW detector located under the rear seat, it is very sensitive. Also the rear floor under the carpet could use some silencing.

Another thread talks even about the pillars. But that is a squeaks and rattles thread, not sound deadening. However, here is the link, it is amazing what some will do to insure silence in their W204.

http://www.benzworld.org/forums/w204...anel-flex.html

 

Interesting that your damplier pro foil is silver....

I just got some damplifier pro for this project and my Foil color is matte black...

Very excited for the matte black, because it will look more OEM and wont have the foil look luckily...

They must have switched the foil color recently....

Also bought luxury liner pro...

Hey Mike, did you use contact adhesive for your luxury liner or did you just plop it down?

PS- damn the luxury liner is HEAVY! quality stuff though....

 

does the damplifier pro just stick to the felt wheel wells or did you have to use extra adhesive or rip off the felt?

doesnt seem like it would be strong enough with its adhesive to stick upside down to felt....

 

A road hazard torn the insulation under my 2010 e350s last night. I can't even find out what it is called to try to find replacement or advice on its replacement - Anyone have information on that part of our cars?

Lynn M. Myrick
Grants Pass Oregon
www.myricklawfirm.com

 

Anyone go through with this and find the result underwhelming?

I just did and I couldn't tell any difference. I used a decimeter to test speeds at 60/70/80/90/100 km hr and I don't get even 1db improvement.

I also did a test at 60km/hr in 2nd gear, 4000 rpm...constant speed - still, no improvement with this.

Thoughts?

Granted the C is quiet enough as it is, but I was bored today so thought I'd try something. Anyone know what model the person had who applied the trunk sound matting and was an expert in acoustic engineering?

 

I just did this and found a HUGE improvement. It's like I'm riding in a different car.

I used a product called Noico that I got from Amazon for $36 (18 sq. feet). I lined the entire spare tire area and any exposed metal in the trunk. There is no noise from the rear of the car anymore.

Trust me when I tell you there is no need to go with a more expensive product. The results could literally not be better.

The only road noise left seems to come from the windows and the roof (maybe just the sunroof). Sure there is a bit of tire noise from the Conti's, but again, it's like a different car.

I was amazed that the plastic spare tire tray has no metal underneath it. And the rubber mat from the factory is a poor excuse of insulating the trunk for sound.

I would HIGHLY recommend this mod. Best $36 you'll ever spend!

I should add that you almost completely lose the throaty exhaust sound. I always liked the tone of that sound. If you like the exhaust sound do not do this. However, for me, the pros outweighed the cons in this case.

 

I guess this is why I'm perplexed. I can't hear anything from the trunk area and I'm wondering if I'm driving the same car as you guys on the thread?

Driving a C300 (2012) with a spare tire in the trunk in that recess.

What are you driving? I mean, I do hear the exhaust when I floor it, and I do like that sound, but I hear no road noise or tire noise or etc from the trunk area. I mean, obviously I hear noise in the car, but not from the back with the seats up.

Tires wise I'm using the Michelin Primacy MXM4 (quiet tire already). Maybe that's why? Did you use a decimeter for a "scientific" review of before/after? What speeds were you testing at?

 

The other piece worth mentioning is are there now concerns of rust? When it's cold out, wouldn't there be moisture in between the dynamat and the actual floor lining? Would that not cause rust assuming things aren't 100% air tight?

 

The fact is, you have to be pretty **** to complain about the noise in these cars. It's a darn quiet car. However, it is present and comes primarily from the rear of the vehicle.
I did not take any decibel readings, but I don't need to. The difference is noticeable to anyone.
(And yes, I have the means, as I am somewhat of an audiophile). It's simply not necessary. It's night and day.

I don't foresee any moisture issues. If anything there would be less, as this material would act as an insulator.

For $36 what do you have to lose?

 

What would I have to lose? You do know that once these things are applied that it's damn near impossible to take off right?

My main issue now is that after applying Dynamat, it's not night and day to me, and after measuring with a decimeter, there is no scientific information indicating that it's quieter.

Unfortunately without having another W204 to test side by side, I'm going off of memory.

To your point, these cars are already quiet. My side project as we go into the fall was to experiment based on the feedback of this thread, and the results were disappointing.

Edit: Curious - are you using a stock exhaust?

 

For starters, I used a different material than you. And you seem very hung up on "science/decibels". I understand your thought process (which is not necessarily incorrect), but decibels are not the be-all end-all of sound.
While I still have some road/tire noise, the exhaust and sound of rough roads, cracks, pot holes, and expansion joints is GREATLY reduced. In reality, the overall noise is lowered to the point I can now hear other things in the car. For example- I had a flashlight in the driver's door pocket. I had forgotten it was there. Since adding the Noico I could hear the flashlight rattling when listening to music. The flashlight has always been there, but I was unable to hear the rattle due to other noise in the vehicle. It was so noticeable, in fact, I had to remove the flashlight because it was driving me crazy.
Perhaps it has more to do with reducing "annoying" sounds, certain frequencies, etc.
Back to decibels- I can play two different speakers at 105 db. One is a $500 speaker, the other $5,000. The better of the speakers, even at the same decibel level, will not fatigue the ear. It will sound as if it's playing at less decibels than the lower grade speaker.
Bottom line, I'm certainly not trying to argue with you. I'm simply sharing my experience so that others may take advantage. Bummer that it didn't work out for you.

 

Yeah, I agree. I spent the better part of today trying to figure out what the experiences have been for fellow Mercedes owners who have decided to undergo this project.

There seems to be three different results.

1) Wow, I can barely hear the exhaust now, but I now hear sounds A, B and C a bit more. Time to tackle those!

2) Meh, there was an improvement and I'm glad I did this project, but it was less than what I expected.

3) Wait, what changed?

I'm completely with you that this is more than a simple DB conversation and that there are multiple variables here. We're probably using two different tires and definitely have used different sound deadening material.

Maybe I went into this with the wrong expectation. To your point that you bring up, you reference exhaust noise and suspension type noises - maybe they are indeed quieter. I'll admit, it's probably my fault here, but I thought the major improvement with this project was with road noise/tire noise, and IMHO they are still present and on those variables my results do not indicate a dramatic change, and admittedly no one on this thread has claimed such an improvement prior to me undergoing this project. That's on me, and I misread what I thought would be improved, so yes, that's wholly my fault.

I stumbled upon this project largely by accident. I had to replace two door seals on my vehicle and as per MB when you buy them, it's trim to fit, so I had quite a bit left over and decided to triple seal some areas. (no I don't have a definite result as far as whether or not they made a difference). My passion to reduce NVH continued onto dynamat and the trunk and thought I'd share my result.

Like you, not here to argue, just to share what my perspective was and glad to read yours!

 

Again, in my opinion, the road noise is coming from the windows and roof. I’m certainly not going to add this product to the roof. And nothing can be done about the windows. So, I’m calling it as good as it gets.

 

Just asking out loud. May I ask why not? I'm considering double glazing for the glass as a pet project when I have time!

 

Ok everyone, in the interest of doing this project properly, here is what I have done.

1) I've removed all of the dynamat from the trunk. This has taken about 8 hours today.

I spent another few hours banging around the trunk/spare tire area, and here are a few things worth noting.

1) There is a small hole that's in the black part of the pan that goes straight outside. Don't ask me why, but it does.

2) The main culprit here is the plastic black area. If you bang around there it's loud as *****. So the focus of the sound deadening should be there.

3) I noticed one of the cords that leaves the trunk area had a loose gasket so all of this time that area had direct exposure to outside air

My concern is definitely one of condensation. On the left and right of the photo, right underneath, is the exhaust.

I live in a rust belt and they use lots of salt here and you mix hot exhaust and cold temperature air, then you will indeed have to deal with rust. I'm glad I caught this.

The exposed metal in the trunk/wheel area here...right on the other side, is the exterior. Sound proofing sheet metal IMHO is stupid. You're just asking for rust issues. One side = hot, one side = cold then you'll run into condensation.

I have since bought hushmat and will be hushmatting the black areas only. I will then hushmat the underside of the trunk mat, and maybe the underside of the black rubber weathertech mat in the trunk.

I will also get that asphalt rustproofing tar crap on the other side of this plastic area. Plastic doesn't rust, so i'll sound insulate on the inside, and I'll use that rustproofing stuff on the other side.

My goal is to leave the metal exposed. It's just stupid to insulate something that the other side of said something is outside, and it's also stupid to insulate something where the cavity (trunk well) has a hole such that it would mix with outside air.

Prior to doing all of this work I'm going to do before/after videos and take noise calculations.

Tomorrow will be a big day.

PS the yellow circle shows where there's a hole straight to the outside. I missed that entirely the first time. There must be a reason for this hole, and no it's not at the lowest point of the pan so it doesn't seem like it's for evacuating any water. Perhaps it's to minimize condensation?