Sound Engineer here…To put this into perspective, I’ve tested dozens of professional sound engineers with this simple test rig: A simple tone generator and a speaker…Two buttons and two volumn controls. Press button 1 and set the volumn to any random level. Now press button 2 and match the volumn. Go back and forth adjusting the levels until they are the same. I then measured the relative signals. The best these professionals could do was to get the two tones within about 3dB of each other. Conclusion: 3dB is pretty much the minimum difference most folks can detect. So, in this case all the work yielded pretty much zero sound deadening. BUT, the insulation value still makes it a worthwhile addition…IMHO.

@MatthewFinlay

6 ай бұрын

This man clearly decibels. Thanks buddy!

@flepper231

5 ай бұрын

This is why you want to see a frequency spectrum and not just decibels. The human ear is way more sensitive in the 1000 to 5000Hz range. It could be that all the sound deadening and absorption made a bigger difference in that region. I see it like this: a well carpeted room "feels" and sounds more quiet than one with hard floors and hardly any furniture, but both could show the same reading on a decibel meter. A luxury car with a leather vs. one with fabric upholstery "sounds" louder, but on a decibel meter probably isn't.

@gutshotgriz3936

5 ай бұрын

@@flepper231 I couldn’t agree more. Well said! Acoustics is a pretty exact science. Psychoacoustics, on the other hand (or how human PERCEIVE sound), is far from exact. Said another way, what a meter ‘reads’ is objective…i.e. it is what it is. What a person perceives is subjective…i.e. subject to interpretation. If someone pads the bejesus out of their car and can hear the difference, more power to them. But sound absorption is a fairly exact science, and in most cases required a combination of hard surfaces, soft surfaces, and air spaces. I used to do a demo for engineers with a small radio, a small wooden box, and some cotton batting insulation. Put the batting over the radio…very little affect. Put the box over the radio…again, very little affect. Put the batting inside the box and put them both over the radio, and…voila! The batting diffuses and absorbes some, and the box reflects what gets past the batting back into the batting. In the case of putting sound insulation inside a car, the affect of placing the sound absorbant material on a metal floor or body panel actually works better at reducing the transmission of sound from inside out. Pedestrians will appreciate not hearing your blasting stereo, but you’ll hear less of a reduction from the guy’s stereo in the car next to you. Yes, sound insulation inside your car will reduce the noise level, but it is likely more due to it’s ability to reduce the road vibrations that turn your body panels into speakers themselves (like the transducers attached to the inside of the body panels in my Honda Ridgeline, effectively turning the truck bed into one giant speaker (and it sounds pretty good!). I offer all this not to encourage or discourage anyone from adding sound deadening materials to their cars…only to cut through the hype, and maybe help them make a more informed decision with a little knowledge of the science involved.

Doing this on my Yaris soon. Already did the doors, spare tire well, rear hatch, floor and under hood. After Each I did a test drive and it made a small but noticeable difference to the noise, mostly at highway speeds(I measured using a calibrated condenser mic i use for speaker building). Interrestingly adding a silicon emulsion to the weatherstripping made a huge difference from wind noise that I wasn't expecting! My Weatherstripping looked tottaly fine, so this was a pleasant surprise.

@MatthewFinlay

8 ай бұрын

Awesome buddy! I’ve wanted to test with a mic and see the difference at different frequencies but man that sounds like a nightmare to test haha. I love doing area by area and hearing the difference too

Ya'll are the best, hope you enjoy the video!

I currently have the headliner out of my '95 F150 (same reason, it's falling down of course) and was considering doing this, not for the noise, but for the insulation properties...I only have enough material to do a single layer but this has convinced me to give it a shot anyway, thanks, love your videos.

@MatthewFinlay

10 ай бұрын

Do it buddy and clearly great minds think alike! Do you have any sound deadening anywhere else in the cab? I don’t and wonder if that screwing my results, aka it might be making a bigger difference but since the noise is coming in from literally everywhere else it’s just seems like not much.

@marks93cobra

10 ай бұрын

​@@MatthewFinlay I do not have anything at the moment. When I replace the nasty-arse-original carpet, I am going to apply it to the floor and on the cab behind the seat (mine's a regular cab) to see if it helps with sound.

@MatthewFinlay

10 ай бұрын

Same! I’ve got a few places where is starting to show it’s age. A carpet shampooer got them smells out but it still looks rough.

You're funnier than half the comedians i've watched

Do you think just adding a thermal barrier padding would accomplish the same thing? Since sound deadening isn’t actually making it more quieterness

@MatthewFinlay

10 ай бұрын

Yes and it may actually be more effective then sound deadening and closer cell foam but I’m honestly outta my element here. It’s also kinda hard to tested or at least I’m not sure how

So it cuts down on summer heat like window tint? How's that possible?

@MatthewFinlay

7 ай бұрын

It’s basically just insulation!

Maybe a radio (or noise maker)on the roof ,before and after,would have showed the actual roof sound deadening affect..👍🏼🤙🏼🤷‍♂️

@MatthewFinlay

10 ай бұрын

That’s a solid point - when it rains it’s silent so it’s definitely doing something but road noise is NOT it haha.

@MatthewFinlay

10 ай бұрын

I swear it’s quieter in there now than before but the decibel meter doesn’t lie! The stereo does sound fuller now - so it’s also helping keep music in. But I didn’t have a real way to test that. I’m still sold on the insulating properties

@ryanmcclendon3309

10 ай бұрын

@@MatthewFinlay the decibel meter will pick up the sound coming from everywhere, not just the roof. I say it can’t hurt,and like you said about the thermal properties,that in it self makes it worth it. 👍🏼

@MatthewFinlay

10 ай бұрын

@ryanmcclendon3309 Solid point that could actually be making a bigger difference but since only the roof is sound deadened you can’t really tell from all the noise coming in everywhere else.

Kazakhstan, I've been. It's not pronounced kuh-zack-uh-stan... it's more like kaz-eck-stan