Sound deadening questions

I believe what this does show is that, like you have stated, CCF is kind of an afterthought for most. It actually matters or it is a waste of money. It needs to be as soft as possible, much like pillow stuffing (but that isn't good for car use and is why we do use CCF).

Too stiff, and it gets to be pointless (or even worse) as you get to the point where you would have been better off just hanging the MLV by itself with no decoupler.

It also shows a pretty wide range of CCF products from 970hz to 1550hz. No where near as good as some, but still a fairly wide range.


This also is similar to CLD tile choice matters. Some are good, some aren't.

MLV is the same as not many actually make this.

3m ACOUSTIC thinsulate works well and I used this quite a bit in my truck, but it must be the acoustic thinsulate.
 
I'll have to check out the acoustic thinsulate as well, do a little cost-compare... and add it to my noise-block compare to see if it compares to the HeatWave in that way as well.
The SecondSkin Heatwave obviously is meant as a thermal insulator as well, and that also has me thinking: It adds an interesting other consideration.

Being in Buffalo NY, it's already cold here, have to run the heat in the car, turn on the heated seats, etc. Heated seats alone help with not running the heat full-blast, but it's usually still a constant in the winter. It could be an extra benefit if either of these serves as a real thermal insulator, that would allow you to turn that interior fan down.

I've even speculated on buying a bunch of heated seat kits, and installing those in the floor just below the carpet, to create an inexpensive electric radiant-heat, to also allow that benefit, but that's just another thought to the end on "reduce fan noise" with cold weather.

Anyway - that's off topic with this particular thread, but I'm glad you mentioned it.

What's your experience with the noise blocking aspect of it? I don't suppose you installed in stages, so that you might have actually had some time to drive around with just damping/thinsulate?
 
why ccf? usually thin enough to fit between vibrating panels and decouple them. it's aftermarket, where automotive manufacturers haven't already accommodated for pillow/jute insulation/space.

why ccf? closed cell foam is supposed to help in high-moisture environments. usual use is in the dry portions of the car, so this benefit is sorta moot.

1/8" hmf (hydrophobic melamine foam) seems to be softer than ccf but also moisture-rejecting. i don't know how well it'd work in these decoupling cases. second-skin sells 1/2" thick as mega-zorb heat insulation, i'm sure others have it as well.

buying blocks of magic eraser (hmf) and cutting it up into strategic spots might work as well to decouple things.

i've lucked out in my car, i've got space behind panels for deadener. i just stick ccf to mlv/sheet-lead 100% and place it.
 
FYI - I got my hands on 12"x12" samples of 0.75 lb and 1.5 lb mass loaded vinyl.
I have lots of 10mm closed cell foam, and I have a section of Honda OEM Jute that isn't Heatwave but is very similar.

That will allow me to compare the relative noise blocking effectiveness of:

  • MLV with a 10mm closed cell foam layer
  • half-weight MLV with a 10mm Jute barrier.

At some point over the winter, I'll build basically a bandpass box, where the center divider will have a 10" square or circle cut from it, with a frame to hold the samples and decouplers.
On one end, will be an opening to seal the mic against to do a REW sweep, so we can see the results by frequency, since that's of course a necessary factor.
On the other end, I'll have an opening to send sound into - I'll probably just stand this whole rig on top of an existing test cabinet that I have for a 6.5" woofer.

I'm personally interested if the thinner/lighter MLV and Jute/Heatwave can be used for weight saving purposes, yet be similarly effective.
...or based on Justin's results, actually seems likely to outperform it between 67hz and 321hz. Possibly even across the whole spectrum, when used in combination.

If you think about tire noise and road noise - which would be why people want to install product beyond simple CLD that stops panel vibrations but doesn't block road noise - lots of it occurs right in that range:
(graphic from a Michelin road noise study whitepaper)
View attachment 14704
That might be exactly why OEMs use jute products (which are similar to heatwave - though there's generic recycled cotton Jute products out there too) rather than CCF in luxury cars.

So right now, I'm busy setting up a windshield/side-windows/A-pillars in my basement lab for some imaging experiments (or rather, near the PC in the open space where my fiancee is not so pleased :lol: ), but this is an objective, measurable, much simpler experiment that Justin's results definitely imply some plausibility.
It's definitely an answer that I want to know the answer to before spring, so it's being added to the list.

We'll see where CCF really stands. :cool:
Especially since the gauntlet was so arrogantly thrown. :wink:
In all my years moderating audio forums, I've had low tolerance for obnoxious trolls - but this is an answer that I do want to have regardless.
 
i don't have any factory jute in my doors. my floorboards are lined with 2-3" thick factory jute below the carpet, factory CLD in strategic places. there's a thick rubber+jute under the front footwells.

i suspect the jute will have an impact as a sound barrier but it won't be as good as mlv. however, it likely weighs less too which helps fuel economy numbers. it also probably checks some environmental/recycled boxes, which is good as well. so there's probably a bunch of business-related reasons to use it over other competing products.

i suspect ccf isn't thick enough to have an impact on anything but high frequencies. its use case is generally decoupling though, not a sound barrier nor deadener.

i think the SDS folks also extolled virtues of the pillow insulation as sound barrier, but i don't know how effective it is when compressed flat (like what happens adding it to doors where there's no space for it)
 
nadams5755 said:
i suspect the jute will have an impact as a sound barrier but it won't be as good as mlv.
Click to expand...
I'm not sure - it is fundamentally different.
But bear in mind, 1/16" MLV is more than half the effectiveness of 1/8" MLV.

There's also the consideration that jute weighs more than CCF. I'll have to compare that on the postal scale too. I'm sure that the weight difference between jute and CCF won't equal 1/16" of MLV, though.

nadams5755 said:
i think the SDS folks also extolled virtues of the pillow insulation as sound barrier, but i don't know how effective it is when compressed flat (like what happens adding it to doors where there's no space for it)
Click to expand...
I agree - the more you compress something, the more rigid it becomes... the more rigid something becomes, the higher the resonant frequency.
Is it likely that Justin's results are another way of arriving at a resonance of a combination of materials?

I'm thinking you are right - if I were a betting man, I'd think if you compressed pillow stuffing to the density of jute, you'd basically have jute. But there's other organic material in jute that apparently give it different properties, I'm sure heatwave isn't simply jute either...
I'm just going to do this as the most basic comparison.
Maybe I'll be ambitious and see if they will send me a heatwave sample for this, too, to see how it compares to OEM.


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geolemon said:
.....
We'll see where CCF really stands. :cool:
Especially since the gauntlet was so arrogantly thrown. :wink:
In all my years moderating audio forums, I've had low tolerance for obnoxious trolls - but this is an answer that I do want to have regardless.
Click to expand...

Hi, since I am a nooby here I was wondering whether you were able to perform your tests and posted them somewhere else?
I hope you had the time and were successful. 🤞
 
I haven't, and my apologies for that.

I do have two squares and a concept for a test rig, but with my position i found myself leading QA for an IT project tied to a government mandate that we engaged a consultant vendor for [to implement before the July deadline] to avoid potentially millions in fines... while also enduring the data sharing aspect of this new national network didn't risk the company millions in lawsuits.

Even with a global QA staff able to work nearly around the clock, we couldn't overcome a vendor who overpromised and underdelivered, and my whole team has been overwhelmed.

You can see the progress on my own install has been just as handicapped.

But I'm glad you reminded me -
Worst case, if push comes to shove, my own car will get to the point where I have to make this decision.

Sent from my LM-G820 using Tapatalk
 
No need to apologize, getting out of this spot between a rock and a hard place has priority. Good luck and success with your project!
 
Justin Zazzi said:
geolemon, if you do get some results with your experiments, I'd love to hear about it too!
Click to expand...
No time yet, but I've purchased two MLV in the two thicknesses, and I'm sitting on piles of MDF and scraps, and have my own install actively going on, so there's no physical barrier to building a rig for sure. Just time constraints.

I haven't built anything yet, but here's my test rig I've worked up in my head:

Two boxes. Really three if you count the one a test speaker will be in.

View attachment 16124

Box 1: will have my calibrated mic held inside. Shouldn't really need to be totally enclosed but we'll see. Will have a 6" hole or so in the other end.

Box 2: basically will have a 6" hole in each end. One end will be used to sandwich a piece of MLV between box 1 and 2, boxes screwed together to hold it tight but make it easy to swap MLV.

Box 3: a test speaker (probably a 3") firing into the 6" hole, screwed tight to box 2. I have a bunch of knocked-up test boxes that I don't care about screwing through.

That way, all the sound will be contained in box 2 - other than sound leaking through the MLV.

I'll do sweeps with REW.
 
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geolemon said:
No time yet, but I've purchased two MLV in the two thicknesses, and I'm sitting on piles of MDF and scraps, and have my own install actively going on, so there's no physical barrier to building a rig for sure. Just time constraints.

I haven't built anything yet, but here's my test rig I've worked up in my head:

Two boxes. Really three if you count the one a test speaker will be in.

View attachment 16124

Box 1: will have my calibrated mic held inside. Shouldn't really need to be totally enclosed but we'll see. Will have a 6" hole or so in the other end.

Box 2: basically will have a 6" hole in each end. One end will be used to sandwich a piece of MLV between box 1 and 2, boxes screwed together to hold it tight but make it easy to swap MLV.

Box 3: a test speaker (probably a 3") firing into the 6" hole, screwed tight to box 2. I have a bunch of knocked-up test boxes that I don't care about screwing through.

That way, all the sound will be contained in box 2 - other than sound leaking through the MLV.

I'll do sweeps with REW.
Click to expand...
Wouldn't that just turn the mlv into a passive radiator? Wouldn't it be better to have the center enclosure vented to atmosphere?
 
ckirocz28 said:
Wouldn't that just turn the mlv into a passive radiator? Wouldn't it be better to have the center enclosure vented to atmosphere?
Click to expand...
I don't think it would. It's not going to be able to move, and it doesn't flex.

All that will happen is we'll measure how much sound permeates and see that on a response plot.

If the center cabinet is open to the outside, then the sound will be able to escape as well, and potentially be picked up by the mic.
In that case, I'd HAVE to seal that mic chamber.

The goal is to have all the sound coming to the mic, only having the path of "through the MLV".

You never know - might even have to do more than just MDF, but hopefully will be good enough for an A/B test.

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