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I must say, it made quite a difference. No scientific tests yet, but I will be doing so.
For reference, on the Primacy MXM4, 17" staggered, at 2'c, with my 2012 C300 W204 with HVAC/Audio off, and before the modification in that youtube video above:
120km/hr: 67db
130kmhr: 69 db
140kmhr: 71db
150kmhr: 72db
Now the problem with measuring sound is that every decimeter is different. I'm just using a DB app on my Samsung phone, so other people's measurements are meaningless. I will be testing and reporting on values again after I make my first run with that mod in the Youtube link. I just went around here doing 100kmhr and I did notice quite a bit of difference.
Anybody have any other ideas? The youtube idea cost me $6.99 for some closed cell rubber weatherstripping. Quick install.
I know you are a fan of the MXM4...however if/when those wear out, perhaps you may want to upgrade to the next gen Premier tires (the direct Michelin replacement of the aging MXM4).
I know you are a fan of the MXM4...however if/when those wear out, perhaps you may want to upgrade to the next gen Premier tires (the direct Michelin replacement of the aging MXM4).
I can't. I'd love to (the Premier AS you mean?) Unfortunately a BUNCH of tires I'd rather run (including the Serenity Plus) tire or the Versado Noir tire from Toyo don't come in 245 40 17 which is the rear tire size!
I can't. I'd love to (the Premier AS you mean?) Unfortunately a BUNCH of tires I'd rather run (including the Serenity Plus) tire or the Versado Noir tire from Toyo don't come in 245 40 17 which is the rear tire size!
I took all 4 splash guards off and installed Dynomat on all the metal around the wheel arches. I then put some second skin closed cell foam mats over the dynomat and the results were impressive. With the combination of the trunk, spare tire area ,behind rear quarter panels, under the rear seats and wheel guards, during winter, with the closed windows you can barely tell the car has studed tires until you open the windows.
The last part I will do is the headliner/roof, it is the last part that needs attention because mercedes didn't put put sound deadning up there, you can really hear the thin can sound during rain falls.
Last edited by W204Motorsports; Feb 21, 2018 at 12:14 PM.
I took all 4 splash guards off and installed Dynomat on all the metal around the wheel arches. I then put some second skin closed cell foam mats over the dynomat and the results were never impressive. With the combination of the trunk, spare tire area ,behind rear quarter panels, under the rear seats and wheel guards, during winter, with the closed windows you can barely tell the car has studed tires until you open the windows.
The last part I will do is the headliner/roof, it is the last part that needs attention because mercedes didn't put put sound deadning up there, you can really hear the thin can sound during rain falls.
Notes underneath each photo. About a $13 mod total for two rolls. Butt tests = great improvement. Tomorrow, the scientific tests will follow with db measurements. Hoping this makes a big improvement!
Two layers of closed cell foam, one stacked on each other, forcing the inside lip up, thus creating a closer seal (at the top)
Door closed, you can see how much of a better seal that is at the top.
I also put in a second layer of weatherstripping above, but the problem is that it doesn't seal at the top. Oh well, it was leftover door seal, so whatever, :P
Last edited by superangrypenguin; Feb 20, 2018 at 08:10 PM.
2db REDUCTION across the board. For people who know how sound levels work, a 2db reduction is insane as noise levels are not a linear increase/decrease.
Most notably, at 150km/hr, I averaged 70db. That's pretty insane. Obviously the results today were in light rain, and the results in my OP were on dry roads, so I'm not comparing apples to apples. I will re-test once it stops frigging raining around here. That said, with the rain today, I would have expected the rain to negatively affect me due to the sound of rain hitting the windshield etc. That said, I have no idea if tire noise is reduced when the tires are on a slightly wet road...
Agree with ltwargssf that Dynomatting (or FatMat) the W204 makes a substantial difference in road noise. Did the entire trunk and spare tire well (without the lid), plus under the rear seat. May do the doors sometime. Most of the road noise now comes through the rear door seals, however the W204 is not a road-noise quiet vehicle to begin with imo.
Road noise can also be dramatically reduced by tire choices, the OEM Michelin Primacy HPs were extremely NOISY especially at highway speed. Now have much quieter, and frankly better riding and gripping/braking tires and is reasonably quiet. The higher profile of 17" rim tires will be quieter than lower profile 18" or larger rim sizes.
With a drag coefficient of 0.26, the W204 should be relatively wind noise free, attested by having driven a substantial amount of my W204's total miles at above 110 MPH.
Tested out my new DB reader today, readings were around 65DB at 120km/h, that's is with loud *** 2 year old Hakapelita 8's winter tires with a lot of studs on them, my summer tires are noticeably quieter so the DB's will be substantially lower.
Last edited by W204Motorsports; Feb 28, 2018 at 08:07 PM.
@ltwargssf: Was this measurement using a cell phone app or a dedicated dB meter? One would think that the SPL would be well into the mid 70's dB range, which is 10 times the Sound Pressure Level or actual sonic energy (especially with studded snow tires).
Guys...you have to keep in mind the DB levels measured are useless unless we are ALL using the same phone AND app or a real DB meter. Even real DB meters vary. All you can do with that data is to figure out, relative to a baseline, if you're going in the right direction or not, and how noisy or not noisy your car is versus others.
You must use the same measuring device. It is 100% useless for me to measure my car versus you measure your car if we're using two different measurement sources.
Ok, so ignore my OP. The suggestion that the Youtube guy offered made NO difference. I was too excited when I made the original DB measurements. The way I had my phone mounted simply blocked a bit of the mic which is how I got a better reading. Since then, I have removed the stuff added to the windowsill since it made no measurable difference.
THAT SAID, please see the below. Solid 2DB gain, on average, tested on the same roads, same temp, and measured from the same device in the same way. not expensive mods! So to summarize
1) Rubber seal at the A pillar between the fender and the two front doors
2) Rubber seal on front two doors, and below the B pillar on the two rear doors, forming a double seal when doors are closed
3) Rubber seal near the C pillar, so when you close the two rear doors there's a strong seal.
4) additional seal on the trunk
@superangrypenguin: Actually any ANSI calibrated device would provide consistent measurements. So any brand or model of omnidirectional sound level meter would be adequate provided that it is properly calibrated. More revealing is to attach the calibrated sound level meter (or microphone) to a digital 1/3 octave spectrum analyzer, which would provide data on which specific frequencies increase with velocity and by how much. Once offending frequencies are identified, the source can be pinpointed with a unidirectional microphone/meter.
In the meantime, recommended for Android is the SPLMeter app, which has the capacity to be calibrated if referenced along side an ANSI standardized SPL meter. Has a multitude of modes, including 1/3 octave display, ID of the loudest frequency, average SPL and rolling peak indicators. FYI.
@superangrypenguin: Actually any ANSI calibrated device would provide consistent measurements. So any brand or model of omnidirectional sound level meter would be adequate provided that it is properly calibrated. More revealing is to attach the calibrated sound level meter (or microphone) to a digital 1/3 octave spectrum analyzer, which would provide data on which specific frequencies increase with velocity and by how much. Once offending frequencies are identified, the source can be pinpointed with a unidirectional microphone/meter.
In the meantime, recommended for Android is the SPLMeter app, which has the capacity to be calibrated if referenced along side an ANSI standardized SPL meter. Has a multitude of modes, including 1/3 octave display, ID of the loudest frequency, average SPL and rolling peak indicators. FYI.
@ltwargssf: Was this measurement using a cell phone app or a dedicated dB meter? One would think that the SPL would be well into the mid 70's dB range, which is 10 times the Sound Pressure Level or actual sonic energy (especially with studded snow tires).
It was my friends DB reader, it was old didnt seem to accurate, I download the SPL app and it seems way more responsive and accurate then whatever old school reader he had. I wont be able to give any results for a bit but I tested at idle, I am at 37-39 DB and when everything is off, I got it as low as 10DB trying not to breed.. lol. In comparison I tried it in a 2012 camry and just sitting with everything off, it was hard to get anything under 12.9dB just to compare in the same environment.
@superangrypenguin I did everything you did with the doors but not the trunk, did you see any difference when doing the trunk or di you do everything at once ? My last area that I have left to add sound deadening are the doors and headliner, the doors im not too worried but the headliner is bugging me, mercedes put zero deadening on the roof, maybe some foam attached to the headliner as far as I can tell. I dont really feel like pulling my headliner off but one of these rainy days I will lol.
Last edited by W204Motorsports; Mar 1, 2018 at 02:18 AM.
It was my friends DB reader, it was old didnt seem to accurate, I download the SPL app and it seems way more responsive and accurate then whatever old school reader he had. I wont be able to give any results for a bit but I tested at idle, I am at 37-39 DB and when everything is off, I got it as low as 10DB trying not to breed.. lol. In comparison I tried it in a 2012 camry and just sitting with everything off, it was hard to get anything under 12.9dB just to compare in the same environment.
@superangrypenguin I did everything you did with the doors but not the trunk, did you see any difference when doing the trunk or di you do everything at once ? My last area that I have left to add sound deadening are the doors and headliner, the doors im not too worried but the headliner is bugging me, mercedes put zero deadening on the roof, maybe some foam attached to the headliner as far as I can tell. I dont really feel like pulling my headliner off but one of these rainy days I will lol.
So the useful chart that you found is one that I have already been referencing. I don't buy the numbers too much, because some of them just don't make sense. Take the W204s, from 2008 to 2014, and take out all of the high end cars (C63, etc), and just look at the C250, C300, C350 (IIRC) and the C180 (IIRC), and the numbers are vastly different, especially at speed. Vastly because even a 1db change is "vast". I'm not sure what their test methodology is, but I wouldn't read much in to it.
As for the trunk, no, I did everything at once, so I don't have the info you're looking at.
I did miss two additional places I added insulation, and I'll take a photo of them. One makes a pretty vast difference.
There are two things to keep in mind when adding insulation. 1) Does it actually touch something else and 2) is the insulation in place or what you are adding - does it have a strong seal?
I can test #1 by using a spray bottle. I'll spray water onto a surface and then I'll close the door to see if the insulation gets wet, if so, they touch.
I can test #2 by using a paper bill, or a sheet of paper, and slamming the door shut with the paper in between the interior and the exterior. I'll then pull on the paper and see how easy (or not) it is for me to pull it out. I've noticed that the A pillar insulation is pretty weak. Yes, you still have to exert some force to pull out the paper, but there's a LOT of wind noise that comes through there (lot being relative to everywhere else). I'm going to see what else I can do to seal that place off.
Also.
It is worth keeping in mind that, in my car, I have a pano sunroof, so there's not THAT much I can do to the headliner unlike your car, just so you know I"m not ignoring that comment, it just doesn't apply to me.
SPL Meter shows 55dba in the car with the engine off. Sound Meter (top app on Android) shows 26dba.
One of these clearly is wrong!!!
Do you have a DI ? Because that seems high, mine is barely hitting 40DB with the SPL Meter although it was in the middle of the night with nothing but the engine running. From what I see you have the frankenstein w204, face lift body, old 3.0 engine so it should be like lower.
Do you have a DI ? Because that seems high, mine is barely hitting 40DB with the SPL Meter although it was in the middle of the night with nothing but the engine running. From what I see you have the frankenstein w204, face lift body, old 3.0 engine so it should be like lower.
Do you mean if my engine utilizes DI? No, but it shouldn't matter because as I indicated, that reading was with the engine off...
There's no way it's like 55db. SPLmeter has to be off.
The app the guy used gives the same measurements as the one I used (I checked), and while I didn't drive at 50mpn (I will on Sunday), this goes to show our W204s are scarily quiet
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