Shhhhh Quiet Please (3rd Gen Sound Deadening Project)

He's showing the frequencies that steel plates are resonating at with different dampers applied. Those waterfall charts are pretty neat--the "depth" axis is time, so you can see how they initially resonate a lot, but it falls off over a third of a second.

Presumably better dampers will cause the resonation to fall off more over time, in the frequency ranges that you care about.
 
Cool thread. I like that youre taking a scientific method toward tracking actual results. Here's another product to consider. I didnt see it in your list . . .

Amazon.com: FatMat 50 Sq Ft x 80 mil Thick Self-Adhesive RattleTrap Sound Deadener Bulk Pack w/Install Kit: Automotive

Check out the reviews . . . customers compare it to Dynamat claiming its just as good, and for half the price. I bought 50 ft/sq and installed it at the beginning of the summer in my doors, rear hatch area, and over the rear wheel wells. 50 ft/sq didnt go nearly as far as I thought it would! I applied it to both layers of sheet metal in the doors. Im going to purchase more and eventually cover the majority of bare sheet metal with it. I still have a large portion of bare metal left to cover, including the front floorboard area, so my results arent very conclusive yet. But it did reduce noise from the rear cabin area, and as many have claimed, it did completely change my sound system after installing in the doors. I hear minor details in my music that I never heard in the past.
 
Cool thread. I like that youre taking a scientific method toward tracking actual results. Here's another product to consider. I didnt see it in your list . . .

Amazon.com: FatMat 50 Sq Ft x 80 mil Thick Self-Adhesive RattleTrap Sound Deadener Bulk Pack w/Install Kit: Automotive

Check out the reviews . . . customers compare it to Dynamat claiming its just as good, and for half the price. I bought 50 ft/sq and installed it at the beginning of the summer in my doors, rear hatch area, and over the rear wheel wells. 50 ft/sq didnt go nearly as far as I thought it would! I applied it to both layers of sheet metal in the doors. Im going to purchase more and eventually cover the majority of bare sheet metal with it. I still have a large portion of bare metal left to cover, including the front floorboard area, so my results arent very conclusive yet. But it did reduce noise from the rear cabin area, and as many have claimed, it did completely change my sound system after installing in the doors. I hear minor details in my music that I never heard in the past.

Fatmat is another alternative to dynamat or second skin but keep in mind it uses asphalt as an adhesive just like peel and seal (which i used in my rear cargo area and wheel wells). Im unsure of how it well it will stick when your car heats up so im saving my butyl based CLD for my doors and roof..

but it still is a cheaper alternative to dynamat
 
Fatmat is another alternative to dynamat or second skin but keep in mind it uses asphalt as an adhesive just like peel and seal (which i used in my rear cargo area and wheel wells). Im unsure of how it well it will stick when your car heats up so im saving my butyl based CLD for my doors and roof..

but it still is a cheaper alternative to dynamat

Yeah, I know there have been some complaints about the sound deadeners that use the rubber asphalt as an adhesive . . . though Ive never heard of it not sticking well, as long as it's properly applied. More commonly you see complaints about it running when it gets really hot. I know that Eastwoods version has issues with running. But you dont see that as a complaint so much with Dynamat for whatever reason. And I didnt see it in the reviews with Rattle Trap either. I removed my door panels in August about 2 months into the summer after installing it and the stuff was plastered to the metal like concrete. Getting it off would be next to impossible. And there were no drips or runs. As long as it's applied to a clean surface, once it heats up and then cools back down it's permanent. Though, I might be a little concerned if I were living in one of the southwestern states.
 
Yeah, I know there have been some complaints about the sound deadeners that use the rubber asphalt as an adhesive . . . though Ive never heard of it not sticking well, as long as it's properly applied. More commonly you see complaints about it running when it gets really hot. I know that Eastwoods version has issues with running. But you dont see that as a complaint so much with Dynamat for whatever reason. And I didnt see it in the reviews with Rattle Trap either. I removed my door panels in August about 2 months into the summer after installing it and the stuff was plastered to the metal like concrete. Getting it off would be next to impossible. And there were no drips or runs. As long as it's applied to a clean surface, once it heats up and then cools back down it's permanent. Though, I might be a little concerned if I were living in one of the southwestern states.

Yea i trust it. I just came across about 20 sq ft of dynamat for real cheap so im using that for my doors. Also im in the LA basin valley a lot and it normally reaches 100-110 in the summers so i dont want to take the chance on vertically mounted areas. However i do this it works just as well.
 
Correct me if I am wrong, but it looks like you purchased a c-weighted sound meter. That might be the reason you're seeing spikes in decibels... see this website for a description on sound meter 'weights'
Frequency Weightings - A-Weighted, C-Weighted or Z-Weighted

The one I recommended was A-weighted

Yeah, looks like I goofed on that one. Time for an Amazon return! But that also leads me to another question. Would there be more value in measuring C-level weighted decibels if my primary goal is to reduce low frequency rumblings caused by suspension and road noise?

I'm also looking in to getting a multi-weighting capable sound level meter, or just buying an A-weighted one and keeping the C-weighted.
 
He's showing the frequencies that steel plates are resonating at with different dampers applied. Those waterfall charts are pretty neat--the "depth" axis is time, so you can see how they initially resonate a lot, but it falls off over a third of a second.

Presumably better dampers will cause the resonation to fall off more over time, in the frequency ranges that you care about.

Thanks a bunch for the explanation on that. I figured it had something to do with how dampers impact resonation, which would require a time sequenced chart to illustrate.
 
Lead sheets are pricey

Just got a quote back from Nuclead for lead sheeting. Kind of blown away by how much this option would cost.

Nuclead-Estimate.jpg


It would be $471 in lead alone to layer on my floor, plus shipping. Whoa!
 
Just got a quote back from Nuclead for lead sheeting. Kind of blown away by how much this option would cost.

Nuclead-Estimate.jpg


It would be $471 in lead alone to layer on my floor, plus shipping. Whoa!

Yea, its pretty damn pricey. IMO lead sheeting is a bit over kill. Even with all the deadening in the world, our trucks aerodynamics arent the greatest and we will still hear wind noise through the windows..
 
Yeah, looks like I goofed on that one. Time for an Amazon return! But that also leads me to another question. Would there be more value in measuring C-level weighted decibels if my primary goal is to reduce low frequency rumblings caused by suspension and road noise?

I'm also looking in to getting a multi-weighting capable sound level meter, or just buying an A-weighted one and keeping the C-weighted.

c-weighting.gif

Looking at this chart, it shows the C-weighted meters will be reading every frequency almost equally, so if you have an excessive amount of low frequencies that your ears are not hearing, the meter will pick them up.. and if the lower frequencies are in higher dB(C) than the higher frequencies dB(C) that your ears are hearing (human ear frequencies), then the meter will be giving dB(C) peaks to a frequency which you may not be able to hear.

a-weighting.gif

If you look at the A-weight chart, the weighting is curved to hear like the human ear does, cutting off lower and higher frequencies that the average person can't hear. So therefore it will be reading dB(A) at nearly the same relativity as your ears.

The C-weighting would be beneficial in a scenario where you would want peak measurements at any given frequency, or pure sound pressures, and the A-weighting will give peak measurements relative to how our ears are hearing the sound pressure... so in other words, a dB(C) measurement could technically be measuring sound pressure levels you cannot or can hardly hear and the dB(A) will give you measurements relative to what your ears can hear.

It's really going to be up to you how in depth you want to get with the measurements, but in my opinion, I think using the A-weight alone would yield satisfactory results relative to what you will be hearing inside the vehicle. Hope I cleared things up instead of mucking it up for you.
 
It's really going to be up to you how in depth you want to get with the measurements, but in my opinion, I think using the A-weight alone would yield satisfactory results relative to what you will be hearing inside the vehicle. Hope I cleared things up instead of mucking it up for you.

Sadly, you're only fueling my "geek out on sound" obsession, which I've never really had before. Actually, scratch that. That I've only started to have in the last few years.

I used to see a bunch of concerts, and have a stack of old ticketmaster concert stubs to prove it (one of my odd collections). As I started getting older, I started to care more about sound. I also started to care about sitting down in a comfy seat rather than standing for 4 hours in general admission. I realized how crappy a lot of bands sound live. Then, I actually came to the realization that it had way more to do about the venue than the actual band itself and started boycotting venues with bad sound. I'd rather see an OK band at a good venue than a great band at a crappy venue. Why? Because I've seen a lot of great bands play at crappy venues and it has completely ruined it for me. And I'm always pleasantly surprised when an OK band sounds great. I saw Mew play at the Henry Fonda in LA and it was absolutely incredible.

All your info is great! Thanks a bunch for sharing. I'm really looking forward to seeing how this project unfolds.
 
Sadly, you're only fueling my "geek out on sound" obsession, which I've never really had before. Actually, scratch that. That I've only started to have in the last few years.

I used to see a bunch of concerts, and have a stack of old ticketmaster concert stubs to prove it (one of my odd collections). As I started getting older, I started to care more about sound. I also started to care about sitting down in a comfy seat rather than standing for 4 hours in general admission. I realized how crappy a lot of bands sound live. Then, I actually came to the realization that it had way more to do about the venue than the actual band itself and started boycotting venues with bad sound. I'd rather see an OK band at a good venue than a great band at a crappy venue. Why? Because I've seen a lot of great bands play at crappy venues and it has completely ruined it for me. And I'm always pleasantly surprised when an OK band sounds great. I saw Mew play at the Henry Fonda in LA and it was absolutely incredible.

All your info is great! Thanks a bunch for sharing. I'm really looking forward to seeing how this project unfolds.


All we need is another hobby, right?? :lmao: well I'm glad I am at least helping. It's nice to meet other people who will evaluate what they are hearing rather than just listen with no concern. When it comes to live shows though, even in a good venue, a bad engineer can ruin the show - I've seen it happen. Also, a good engineer can also make some bands sound 'better,' but you can never turn down the 'suck-fader' to make somebody suck less, so usually bad bands always sound bad. I love music and sound, and just recording and writing songs on my own drove me to switch from a Computer Science major to Audio Production Technologies. I am still a big computer nerd, and will probably go back for computers eventually, but my heart is in sound.
This thread is coming along nicely, and I really don't think there has been this much scientific effort put into this subject since the original engineers designed these bad boys! :D Keep it coming!! :banana:
 
I love music and sound, and just recording and writing songs on my own drove me to switch from a Computer Science major to Audio Production Technologies. I am still a big computer nerd, and will probably go back for computers eventually, but my heart is in sound.

Ah, computer science! I'm a healthcare IT manager and live in the world of data, workflows, and acronyms. All the healthcare.gov stuff? Not my project and not in any of those companies, but I work in that same world. CMS is a really crappy business partner, so no surprises on that one. Regardless of whatever political party is in power.

This thread is coming along nicely, and I really don't think there has been this much scientific effort put into this subject since the original engineers designed these bad boys! :D Keep it coming!! :banana:

Thanks! I wouldn't have tried to undertake a project like this on my own. These forums have a ton of expertise and knowledge of all sorts hanging out here. Nice to know I don't have to be an expert on anything and can bounce ideas off of people. And scientific effort? Sheesh. If I can do something with a beer in my hand, I just call it bullshtting!
 
Well, guess I stumbled upon another project before I can start / complete the sound deadening project.

Just picked up a supercharger from eBay. I finally found a reason to use this emoticon now, too.

:girl:

Time to upgrade my engine bay to look something like this:

supercharged4runner004.jpg~original


And of course, this means baseline testing both with and without the supercharger installed. See, priorities in life!
 
Congrats on the supercharger!! Yeah...this is a no brainier! Anytime you can score more power...you have to take it.:zoom:

If you don't mind me asking...what did you pay for your S/C? And is yours a 1st or 2nd gen?

Thanks and enjoy! I'm jealous...:hail:
 
Congrats on the supercharger!! Yeah...this is a no brainier! Anytime you can score more power...you have to take it.:zoom:

If you don't mind me asking...what did you pay for your S/C? And is yours a 1st or 2nd gen?

Thanks and enjoy! I'm jealous...:hail:

Woohoo, performance! I'm used to zipping around in my Audi A3. Driving the stock 4runner around is kind of like pushing a fat kid up a staircase on a sprained ankle. Not that I'm ever expecting the 4runner to be anywhere near as nimble and quick as my A3 ever, but still...

I was debating whether or not to hold out for the 2nd Gen (4th Gen, actually) S/C, or see if I can get a reasonably priced 1st (3rd Gen) S/C. As I understand it, there really isn't much of a difference between the two other than the 2nd gen is cast as a single unit and cheaper to rebuild. Same performance specs, so not a lot of difference. It kind of came down to price / condition. If I found a great condition 1st gen for under $1300, I was going to grab it. If I found a reasonable condition 2nd gen for under $1600, purchase time.

For $1225 including shipping, I have this coming to my door soon:

Supercharger.jpg


I'll start up a new thread on installation, performance observations, etc. Kind of like in same vein as this thread. My master plan is to create a build thread someday and link back to these threads as the step-by-step guides on how I was able to perform these upgrades and what the rationale was behind them.
 
I took some sound pressure level measurements today. Deadening materials were Raamat and PS ensolite, used full coverage, even double coverage on some critical areas.

Spl measurements before:
72 dbm parked with engine idling
94 dbm cruising at 70 mph

Spl measurements after:
At idle the sound level was below my meter's lower limit of 53 dbm
71 dbm cruising at 70 mph.

A 3 dbm reduction requires cutting sound energy by 50%, making this a pretty dramatic change. Road trips are much more pleasant, and my music now has a low noise floor to rise up from.
 
Wow... well done. I just finished lining only the outer skin of the doors in mine to help with an amp and noticed a difference. I can only imagine how quiet yours has become
 
So, winter hit. Snowboarding season and I've been up at Mt. Hood every weekend. I've been traveling for work 4 out of the last 8 weeks, too. Garage wiring still isn't working and the driveway has a stack of garage shelves I haven't been able to throw out yet. And first gear just went out on me.

This sound deadening project is really taking a back seat. I'm hoping to tackle this as soon as it starts getting warm again. Right now I'm looking for rebuilt manual transmissions. Ug...
 

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