How to Sound Deaden Your Car. How Quiet Can You Make It? Results Before and After. 

I added chapters to this video because this video is so long. If you guys have questions check the chapters of the video and you may very well find your answer. Thanks for watching. Sound Deadening Products: Noico 80ml Butyl Rubber: amzn.to/3mUUVtr Noico 150ml Closed Cell Foam: amzn.to/3DKgIKZ Mass Loaded Vinyl: amzn.to/3lLBhAF Products and Tools I used to install the sound dampeners: Noico Roller: amzn.to/3mXq6nP Kneeling Pad: amzn.to/2Z2V85E Trim Removal Tools: amzn.to/3lKZLKs Clip Release Tool: amzn.to/3ANAWBA Scissors: amzn.to/3jqrlev Utility Knife: amzn.to/3pbau2L Degreaser: amzn.to/3lIB4Oy Vinyl Cement: amzn.to/2YYpx5g Foil Tape: amzn.to/3lIssHR My Amazon Store: www.amazon.com/shop/repairgeek Help support the channel, buy using my Amazon links As an Amazon Associate I earn from qualifying purchases and your cost is exactly the same.

I am a retired Mercedes Benz technician. Here I am talking about only S class. Yes they engineered to be quite. Every inch of this car has extraordinary insulation including very heavy padded floor carpet. It is so heavy that flooded car carpets are impossible to remove by one person, even though it is divided in 4 sections. Your job is outstanding and very laborious. Once you get old ( 60s ) you won’t believe that was you, who can perform such a hard work. I enjoyed and appreciate your each minute of hard work. Thanks 🙏

I put two bits of foam in my ears and the difference was AMAZING.

As an audio engineer I think you’ve limited yourself to analyzing decibels which is just a measure of loudness when in reality what is evident from the video and even more important in my opinion is the frequency spectrum was reduced to the lower vibrational waves which will never go away unless you replace the floorboard with a few inches of lead. You have successfully reduced the noise and loudness of the mid and high frequency range of hearing which clearly results in less harshness while driving leading to reduced fatigue and a better driving experience.

If you attempt testing noise level again, use a spectrum analyzer instead of a db meter. It will show you what differences there are at different frequencies rather than just a general noise level.

Excellent video! FACT: On the Jazz/Fit or any Hondas, the biggest reduction of road noise/tyre roar comes from extensively treating the FRONT fender chamber and fender liners. The road noise creeps out via that tall thin gap behind the front door hinges. The fender liner must be lined with Dynamat type of constrained layer dampener+foam, while the chamber should be sprayed with underseal. Most importantly, the tiny airspace directly behind where mudflaps reside shd be stuffed with waterproof material such as Thinsulate. This will give significant reduction of road noise which must be BALANCED by a reduction of engine noise by treating the underside of hood. And then, you can progress to the next most significant area (in order of importance): 2. The 4 doors 3. The 2 rear wheel humps 4. Front floor 5. Rear floor 6. Roof (the last). For a further highly noticeable reduction in exterior noises, and done to all my Hondas: Install 3M additional rubber door seals. Stuff THINSULATE into both A-pillars as both are hollow with tiny holes acting as a flute, and amplifying windnoise and tyre noise that slams onto the 2 pillars. In your situation, since you hv even used MLV, thats excellent. But you have missed out 4 critically important areas that can give you another approx 4db of reduction: 1. Front fender wells (super critical) 2. Under undercarriage (shd be sprayed with any suitable compound or just plain undersealant) Significant difference. 3. Stuffing A and C pillars with Thinsulate. 4. Additional rubber door seals. All the above were done to my 9yr old Honda City and the results were marvellous! Avg 8db of reduction at 80kmh over the same stretch of tarmac. No MLVs used. Even the Honda mechanics noticed the significantly quiet interior😜

Having 3 different layer tests throughout one video was by far the most in-depth I’ve seen someone go on this topic. Well done.

I have sound deadened a large sprinter van and can confirm that 20% coverage of butyl rubber works perfectly. Place a square of butyl in the center of large panels to stop reverberation. Don't bother with tightly pressed curves because they don't reverberate. Olny use the closed cell foam on inside of side, roof and door panels. Forget the vinyl, stock carpet is fine. High end cars with double glazed windows are the quietest you will see. A very limiting factor with cheap cars is thin glass which lets in lots of outside noise.

Considering that every 3 db less, reduces the perceived noise to half for the human ear, you just reduced the noise in your car to less than half 👏👏👏👏 The sound db scale, is not linear for the human ear, it’s progressive 😉

Nice work! The decibel scale is logarithmic, so even a 1.5-2 dB drop like you had in the early stage is pretty significant

this is a video that ask people NOT to do the hard work by themselves, 'cause it's too damn hard. Thanks. I cannot image, how much planning, how many miles of test drive, how many hours of research, all of these spent on this video. Huge appreciation. I cannot do it.

I did an entire 80 series landcruiser . Floor, doors, roof firewall and tailgate with foil and foam. took me 50 hours to strip, then install and reassemble. The difference in that particular vehicle was amazing. Tip for viewers= if you can still see the diamond pattern in the foil, you have NOT rolled it down enough and results will suffer.

Recently restored an early 90’s Nissan. Adding butyl and foam inside the body and door panels made a noticeable difference in road noise, similar to what you observed. Replacing the 30 year old door and window seals made a significant difference as well. The amount of time you spent making this video is commendable. I like how you told the purpose and function of each layer, and what they will and will not do.

As someone that works in the NVH industry for a car manufacture, I will add that another thing you want to do when sound proofing a car is to cover up any holes that are not being used for bolts or plastic clips. Like at 25:55 on the left side where the wiring harness runs along below the doors, there's a small hole that can be covered just below the harness. Block off the open areas around the seat belt retractors, etc. Any open holes are a pathway for noise.

That final comparison gives me 2 impressions : You got rid of most of the high frequency hisses that are really irritating and you end up hearing the engine more than the road noise. I'm fairly sure (even without a drastic reduction in dB) that the result is a much less fatiguing noise compared to what it was before

You do NOT need 100% coverage, and this can be validated with knock-testing. It's especially easy to test with the roof, because when you tap again a proper application of CLD tiles on the roof it will make a very dead "thunk" noise as opposed to the hollow noise without the contrained-layer applied. This difference in sound is due to the panel's inability to resonate due to the increased inertia of the butyl layer. You should also apply the CLD to the pillars, especially the larger C or D pillars, because they can act like an echo chamber. The inner door panels do not need it as much

It's such a pleasant change to find a video that doesn't dumb down a subject.

4-5 DB is more than appreciable, 3 db means that the sound pressure is cut in half, the db scale is logarythmic so the work you done worth every penny and sweat invested. going further involves redesigning the suspension links to the shell and of course, the powertrain supports. even the tire choice have an impact on the noise transmitted to the shell. The exhaust system have an important role to play, even if it seems not loud, it generates frequencies that are likely easier to transfer to the shell. The noise that the easier to dampen is the noise that is not produced. you done a very good job on your Honda Fit.

OH MY GOSH. I only did the back area of my Mazda and there’s no way I was adding recording it for other people. No one will EVER know the work you put into this video and it’s greatly appreciated. Thank you

Musical detail was what I noticed most when I did my 2013 Nissan Versa. Though I used both an asphalt-based sheet and a spray deadener/insulator. Then I did the foam (two layers in most places) and MLV on top. I also stuffed hollow areas with closed cell foam and then insulated inside the wheel wells where I could. I got about 7.5 dB reduction total.

There's a MASSIVE change in the pitch of the noise. The best way I can describe it is tire hiss, the tire hiss sound of the tires on the pavement is drastically reduced. Thanks again for the video, this is VERY informative and I appreciate it. I'm in the process of trying to quiet down our 2022 Bronco while upgrading the horrible audio system to something that is much more enjoyable. This is a brand new territory for me when it comes to installing sound deadening and your video has been the best one I have watched out of maybe 10 videos that are covering this process. Thanks again!

@RepairGeek~ Excellent video! I'm a Speech Language Pathologist & Audiologist. I wanted to add some observations about your "sound db meter measurements" and the limitations of the type of db meter you used to measure the "Before and After" noise changes. Sound is measured by TWO aspects: # 1] Amplitude (Volume/Loudness): High Amplitude is Loud and Low Amplitude is Quiet. Amplitude is measured in Decibels (db). #2] The "Frequency" (Pitch) High frequency is a high-pitched sound, low frequency is, well, low. We measure frequency in hertz (Hz) and kilohertz (kHz), which is thousands of hertz. Lower pitches travel further and pass through objects more easily than higher frequency sounds. Every sound we hear, including each other's voices, is a complex combination of different high and low frequencies. The frequencies and how we hear them can be impacted by the environment. All the pitches that make up any one sound are important to the experience of that sound and the removal or quieting of any of them, can change our experience of that sound. So, for example, when you hear someone talking on the other side of a door their voice sounds different because the higher frequencies in their voice do not carry through the door as well as the lower pitch parts. When high pitch sounds are quieter they sound like they are further away, because high pitch sounds/high frequencies don't travel as far or through objects as well as low pitch sounds/low frequencies. (It's why the kid in your elementary school class with the deep voice always gets caught talking in class... because their voice carries further and more powerfully than the kids with higher pitched voices.) SO.....while your DB METER measured the gross AMPLITUDE/LOUDNESS, it did NOT measure the FREQUENCY/PITCH of the sounds inside the Honda while you were driving. This is why you perceived a bigger difference in the sound level within your car after you added the sound deadening than what your DB meter indicated. The DB Meter you utilized did not measure the change in Frequency/Pitch of the sound within the car!! Sounds, such as the tires whining against the road or howling of wind outside the car, are HIGH PITCHED SOUNDS. Your sound deadening install altered the Frequency/Pitch of those sounds too!! I would venture to guess that, IF you were to MEASURE BOTH the DECIBELS and HERTZ within YOUR Honda Fit vs another Honda Fit of the same year, you would see a tangible and SIGNIFICANT IMPROVEMENT IN YOUR CAR after the sound reading install!! I believe you altered the interior sound much more than your test revealed! Great video Repair Geek! ~~Christy~~

This looks like a lot of work, installing sound deadening and recording it. Thanks for making this video 👍

I improved the noise level in my car by leaving the wife at home.

As a person who have disassembled totally sound proof cars and noisy buckets, i've never seen something like that in the video that people install. Quiet cars have two differences on the interior: 1) Thicker glass like BMW and Mercedes going with better weather seals on the doors 2) Triple as thick and heavy carpet with integrated foam pads compared to normal cars When you want to absorb sound waves you need volume and density in sound absorbing insulation eg dense foam pads, rock wool etc, if you just make the sheet metal heavier and add mass with the things in the video what you do is just absorb the resonance of the metal so it usually tunes to lower frequencies and the best thing it does is get rid of rattling. It might seem like it reduces noise but only because the chassis now tunes to a narrower frequency spectrum, and in fact those material are sound reflecting not sound ABSORBING, meaning any sound produced will be reflected till it fades out. If you are looking to sound proof a car save your money and install some pads like in this video in vital areas like in transmission tunel, near the muffler, in the center of the door skin, some roof, the firewall etc, you'll see that most are already installed from the factory so next step is to install some new weather seals and grab a Mercedes ML carpet or similar from the scrap yard cut it up to pattern and install it under your stock one.

You worked your butt off in a thorough and methodical manner. Thank you, and I'm not even going to sound deaden my car. It was cool watching you master a challenge!

Great job! This reminds me of the very first car I did sound deadening on :) I've learned a couple of things since how to make it easier/cheaper: - The amount of butyl rubber is excessive here, you only need to cover 40-60% of the bigger flatter surfaces. Covering everything else typically only serves aesthetics. - Use aluminum duct tape to seal butyl rubber edges for aesthetics and to prevent the butyl to squeezing out and sticking to whatever is there on a hot summer day. Vinyl seems to do great job covering the mess also! - Thin foam doesn't help so much on the floor, I only had noticeable results using 6-10mm foam but that creates a lot of troubles when putting the interior back together. Factory carpet does some sound deadening as well, adding a thin layer of foam wouldn't change much. - Factory deadening starts falling off after a couple of years, it's best to get rid of it if possible, some heat may help a bit. - Don't push butyl rubber so hard, those squares on a foil side are there for a reason. - Make sure it's warm enough when applying butyl rubber (high 70s and up), use heat gun otherwise, especially when doing doors/roof. - Use heavier butyl rubber (like 150mil) on wheel arches and flat floor panels. - Use some butyl rubber on the hood and try to squeeze into fender cavities and cover fender panels as well. - Using foam on a ceiling doesn't help sound deadening as much but creates a strong heat barrier. This is great during warm season, not as good when it's below freezing since the layer of snow and ice you may have on the roof would never melt. Same applies to the hood panel. - As far as efficiency goes, this would be my order: doors (including hatch/trunk), fenders, roof, firewall (very labor-intensive), hood, wheel arches, floor. Doing doors + fenders + hood is least effort and gives great results.

I would have thought doing the firewall would be the first place to start.

I studied noise control at university. I wouldn’t expect a lot of reduction from treating the floors, roof and firewall since the window glass has no treatment and I suspect a lot of direct noise radiation comes from the glass. I did a “poor man’s” treatment of my car with limited results. Thanks for your video! I won’t waste time or money trying to do a deluxe treatment. Clearly a case of diminishing returns!

The thing is, youre not only making road noice lower. You also optimize the overall stereo sound in the car. So i would say its absolutely worth it. Great work.

Hands down this is the best most informative DIY vlog on sound deadening. I had watched at least a dozen videos before this and contemplated on whether to watch another and I am so glad I did ! So thorough with all the db tests at different intervals, exactly what I needed to help make a decision on sound deadening my 2nd Gen Scion xB. For me now I don't think I will bother with the cost and time to do this. So glad I came across this video. Thanks Repair Geek

As far as i understand, every 3dB is half/double the loudness as perceived by the ears, so a 4-5dB difference, as you have said, is noticeable. I've got a BMW 4 series that has sound insulating windscreen, which is not fitted to the BMW X1 range ... the road noise and traffic noise difference inside is huge, even though it's only the windscreen that's insulated. Great experiment, thanks for taking us on your journey.

Most comprehensive comparison I've EVER seen. Thank you for your time and effort. You helped me decide which route to go.

I’ve been playing the same game with my landcruiser 80 series for awhile. I used the same tin butyl, a slightly thicker closed cell foam, and a giant sheet 45x70” of mlv over the cargo floor that I had left over from soundproofing pipes in my house (which works btw). My vehicle, like your Honda, already had segments of the floor and wheel Wells coated with a butyl skin in certain areas from the factory. I did not apply a foam underlayment under the mlv sheet, but if this video was out i would have. That being said I believe it still benefited quite a bit. Following the vehicle manufacturers line of thinking, I didn’t completely cover surfaces, but rather have large pieces of butyl staggered on the inside quarter panels like spots on a cow. For me, welding rust holes shut, and covering unnecessary holes with butyl made the biggest difference. I can also recommend from experience, a sprayed asphalt/rubberized undercoating on the bottom of the body makes a big difference for sound. Particularly in the front and rear exterior wheel Wells

It’s really nice to see someone like this guy out here doing damn good work. He’s highly detailed, competent, organized and honest. No BS, this guy is a rare human.

Something you should be aware of is that the road surface together with the tires makes a massive amount of difference. So whenever you were recording different speeds on the road, you needed to record on exactly the same piece of road to leave that variable out.

I have successfully removed a LOT of drone noise and NVH (noise, vibration and harshness) from my car after doing four things that made a big difference. (And I had like everyone else started off by trying to get things quiet using butyl mats/dynamat etc. I realised that that had a very limited effect and beginners usually end up sticking down way too much of the stuff and later regret it because you start thinking how much you’ve weighed the car down by. And a year or three down the line you end up taking two thirds of it back out - or trying to). Here in England I run a 2011 Ford Mondeo (Fusion) estate/station wagon. MY FOUR BIG TIPS for INSTANTLY reducing noise (REMEMBER - you are NOT going to get your sub-$25thousand dollar car to hush like a Bentley. BUT - you can get a LONG way towards it.) NUMBER ONE - REPLACE YOUR TYRES. If you want quiet, you need to LIFT the car further away from the ground and have less tyre in contact with the ground. So run NARROWER tyres with a TALLER SIDE WALL and if you can a SMALLER RIM SIZE. I replaced my 215 55 R17 tyres with 205 65 R16 tyres on replaced 16 inch rims. This dramatically reduced the rolling drone of the tyres on the road and gave a softer ride because the taller side wall raised the car further above the ground as well as reducing the contact with the ground. Yes you will get less of a sporty ride but I’m not interested in a sporty ride. NUMBER TWO - INSERT SURGICAL TUBING into all your door seals. You need to improve resistance to outside sounds coming in. Adding surgical tubing into all your door seals makes them nice and snug. Don’t go TOO tight though - get the right tube width - or else you won’t be able to shut the doors and you’ll feel real dumb. NUMBER THREE - Buy cheap ‘RECON FOAM’ cut it up into small cubes and shove it compacted into all the empty cavities under the trim around the console, footwells and glove compartment. You wouldn’t believe how many just open holes there are in that area doing nothing but causing sound from the engine and up from the ground to reverberate around. Foam (NEVER USE SPRAY FOAM - it will enter places you really don’t want it to get and you will never get it out in the event of a repair requirement) dampens all that NVH and contributes to the multi-pronged solution we are going for. You need to do a LOT of things to add up to removing those decibels. NUMBER FOUR - Go to the back of the car. On most cars under the rear bumper on the left and right corner areas hidden away you will find a one-way ventilation flap on each side of the car. These are interior pressure flaps that allow air to escape from the car when the doors are closed and to allow ‘used’ air to escape from the cabin as new air enters from the front air vents. BUT they usually are located behind a very large cavity that sits adjacent to the rear wheel arches. In some cars you can reach into this large empty cavity through the back hole at the rear of the small felt door/closet you find in the left or right wall of the boot/trunk - the little hidden hole you might put an emergency traffic cone or yellow jacket in for example. I discovered these cavities causes a LOT of droning noise. The noise from the rear wheel comes straight through them, reverberates and comes out through the interior rear air escape vents. FILL ONE OF THESE CAVITIES UP! Don’t fill both - you need one to maintain the ability to release the cabin air pressure remember - and often the fuel fill area prevents access to one of the cavities depending on if you have a left or right hand drive. But if you can get access to one side - fill it up tight with old rags, recon foam, old carpet that can be scrunched up - you want as much as possible to remove cavity space that creates reverb. Use anything not too heavy but DENSE. So recon foam, being more dense, is a lot better at dampening and muffling drone than, say, bubble wrap. Pack it in tight - and there’s room for a LOT of foam and rags in there. The more you stuff in the quieter you'll get. This for me REMOVED 80 to 90% of the heavy drone in the back of the car - which had been particularly irksome on long motorway journeys. NUMBER FOUR POINT ONE (!) Not essential but this improved my car dramatically - If your car is one of those that tilts down slightly towards the front end (to allow for the backend to dip slightly and the car to even out when the trunk is fully loaded) buy a pair of polyurethane lifting spacers to sit at the top of your front struts. Your garage can fit them for about $250. They again move the front end higher off the ground, away from the noise of the road. So coupled with the tyres we’re really changing how close we are to the noise of the road. Plus they make the car sit more evenly and look a lot better... SO These are my main tips for really getting to a quieter, pleasant drive. And they have really worked for me. I wish you all the best with your own particular car - every one has its quirks and every one will have slightly different solutions. It's a lot of sometimes unpleasant work, but persevere and you can get a nice result.

Thank you for the most comprehensive car sound deadening guide and results comparison video on RU-vid! I've watched nearly all the sound deadening guides on RU-vid and this one is lightyears ahead of them. I really appreciate the methodical comparisons you have shown us. Great video and kudos to you! 👍👍

This is a fantastically documented account of sound deadening a car. The video is logically laid-out and the comparison between each layer makes it that much more thorough. Thank you very much.

17:01 compared to 17:09 there is a change with the comfort fan setting. See the dial move from position 2 or 3 down to the off position. No, I don’t think this was misleading… but I do think it may have impacted your reading by some unknown amount of decibels. What ever the case, wonderful video!

Great content! Thinking about sound deadening my diesel pickup. After watching this video, my expectations have definitely changed. Thank you for all the work you've put into this content.

Appreciate the work, man! Both the sound deadening and the making of the video. It'll definitely be an inspiration for many.

When you knock down the DBs by 5, you have effectively knocked down the sound level by 50%! Thanks for your hard work

I just picked up a 1985 vw golf. It sounds like a coffee can rolling down the road. Your video helped a bunch!! Thank you for all the hard work!

About a year ago, I purchased a new 2022 Nissan Versa as a commute car (I'm 96 miles door-to-door to work). I hadn't even thought about sound-deadening until watching this. And this tutorial is so complete, I can't see a reason not to do it.

That's about 50% decrease in loudness. dB reading are not linear. Good video man.

Your dedication to documenting the process and showing results is a rare sight to see. You have my thumbs up.

Ive deadened more vehicles than almost anyone else i know and i can confirm - it makes a massive difference. Not just for insulation but it really does make an audible difference. And remember! Every 3db is is twice the volume meaning 150db is twice as loud as 147db.

-4 db of noise sound is about -63% reduction. So, your work actually was pretty darn good. I notice that you have not dampened the side panels yet. It may be worthwhile to do that since the metal on the side of the body is thin and wide. So dampening it may reduce the higher frequency "rattling" noise.

Fantastic work! I'm really blown away by how much effort you put into this video and this little car. Hope the car lasts you a long time! Greetings from Germany

This is amazing! One major source of noise, especially at higher speeds, is the air passing the car.. check on your door seals, make sure they are not cracking, are elastic and have good surface contact. For some cars there are even comfort seals for extra noise reduction.

Best sound deadening explanation and demo on RU-vid. Much appreciated!

I once had to make a "quiet" box for my wife's blender. She bought the "mass-loaded" fabric from a music store for me. Her and I had to put TWO layers of it inside of an IKEA cupboard to get 20 dB difference. No windows though :)

It's worth mentioning that Decibels are an exponential measurement. A decrease in 5 DB from 80 to 75 is much more significant than from 45 to 40. I think the results were pretty good. Edit: I see others have said this. Still a good video.

Great work! I also tried to sound proof my car and I searched so many disassembling videos of some expensive cars and realised that they also have deadener on the inside of the car doors + sound absorbing material such as felt just the thick same as the carpet (roll royce/ mercedes/ lexus/ bentley/volvo), they also put thick felt between the plastic cover wheel well and the chassis for absorbing road noise, next to the air pressure balancing vein in the trunk they covered by felt + some foam blocks, at some pillar covers they also add foam or felt. I did make the soundproofing for my car including 4 doors, 4 wheel wells with some damping stuffs bought online with butyl, soft foam,thick felt. The doors when closing are much more better - feel more solid and there is only little tires sound echoing from the road concrete separator through the doors when driving on the high way than before. I also recorded my car sound when driving on the harsh road and the result was the frequency from 50hz to 1500hz is the most annoying sounds. I felt that it came from the chassis vibrating not the sound from the tire because I drove very slowly. So I think that adding some damping material to the flat iron surface to absorb the vibrating will lead to result as you did to the floor.

This is an astonishing video. One of the best I have ever come across on RU-vid. Big big congrants!

I was invested the minute you explained all three pads. I know you did this to show how much road noise or general noise in the cabin but I’m sure with the proper speaker setup now it would be a dream to go for a ride with your favorite music.

You should have definitely put sound deadening on top of the fender liner in the wheel wheel, it’s what a lot of manufacturers do and tires are one of the top 2 source of noise on cars even beating wind noise sometimes. You HAVE to do the wheel well if you want good results. It would be awesome if you did that and did a update video.

Very nice stuff. I just did a lot of this to my 2017 Civic... Honda really made it easy to get rid of a lot of the panels. Only noticed a bit of a drop in road noise but the frequency response from music just sounds so much better. And it makes your doors sound like vault doors too!

Probably the most thorough video on this subject I've stumbled across. I have watched videos on this before specific to my vehicle at the time but never seen one quite this detailed. I've also done my doors before but not the floor or roof, taking all the stuff out of my car seem hugely daunting when I don't have a garage lol. Thanks though would love to do it one day 😊

Glad someone finally conducted this test! I didn't expect to find it, but thank you for sharing this helpful information.

Absolutely love that you took the time to measure the difference after each addition, thanks very much for your thorough process!

That's a massive amount of work, thank you for documenting it! Like you said with the sources of the sound, if the car is over 5-7 years old you might see great results from replacing the strut mounts since that's the load bearing rubber isolation between the wheels and the chassis.

Really makes me appreciate how well built and relatively quiet my 15 year old Passat is as the noise is till okay even when I’m at 200km/h

Great video. From a car audio perspective, I bet this made a night and day difference versus your 5-6db road noise difference. Low end sound, panel vibration reduction, escaping sound outside of the vehicle reduction, etc. If you were focusing on car audio, a before and after of your interior speakers with and without the sound deadening would have been awesome. Cheers

This channel is so good. I love the elements of Project Farm-type research and process of application. Thank you!

Great work, - well done! I know how much of a pain it is, as I've done quite a few of my cars over the years. Best result was with a Lotus Elise, but that car started with virtually zero sound deadening, so it made a dramatic difference. One thing I found during my various projects, is that removing the the wheel-well liners, spraying heavy-duty deadener into the bare wheel arches, then also coating the inside of the liners as well, made a dramatic difference to road/tyre noise. Just as much as doing the floor with butyl + foam. In the lotus I also did HD thermal + laminated felt on the bulkhead (firewall). Overall, it made the little beast an acceptable daily drive and I could throw away the earplugs (literally). Even the wife would then ride along... Thanks for the video!

I did that only on the floor of my car and i can feel the difference before and after and then i just saw your video and i feel much appreciate to your hard work, thank you.

Wow! I can say that's a good enough difference! Congrats! I've been thinking in the past how can i do it, but now i have watched your video i got a lot of ideas. I enjoyed every minute of it. Thanks!

Nicely done. You are definitely not exaggerating the effort that went into this production.

I've done a lot of sound deadening and the area that helps the most is the doors and wheel arch's. sound mostly comes from the wheel arches and the glass. Apply fabric to the arches and back with deadening or heavy foam. The floor makes the least difference. Firewall is also a good location. You can use expanda foam in sealed panels

I've been on the fence about doing this project on my gti and this confirmed I would be happy to spend the time and money, thank you!

Great video. I'm currently falling down a sound dampening/deadening rabbit hole studying all of this and your video comparisons really helped. Thanks for your efforts!

Thanks for the video, u got my respect for the amount of work and effort not only by diy and soundproofing your car but to show us the difference on the decibel for every layer u installed. Im driving a honda fit too and been always frustated by the road noise and always try to use a quite tire. Will be installing soundproof too. Thanks again

Thank you for all your videos, you are definitely teaching us and giving us courage to attempt jobs like this. I appreciate all the work you do.

That was actually a fairly comprehensive example of how sound damping products can be utilized in a passenger car and the effect it can have. Good work.

This video is one of very best 'HOw TO" videos on RU-vid. It is done seriously, with caveats that are explained well enough for an inexperienced person to understand. I have been considering putting some sound deadening material in my car, but having viewed this video, I'm not so sure whether I want to take on that size of a project. It would take me 2 to 4 weeks of part time work to complete the job and my car would not be available during that time for use. It was good to see how a professional would do it and I don't think I can gain that much patience and knowhow to complete the job. I am going to look at replacing some of the tires (before they actually wear out) and I probably will put some of the butyl sheet in exterior portions of the car ( door panels, trunk lid, wheelwells, trunk floor, engine compartment and firewall & rear seat area but not under the front seat seats and not on the roof - due to the air bags that I don't want to accidentally actiivate resulting in a very large cost to replace if they are disturbed. I feel competent to do the above described areas without too much trouble and less down time from the use of the car. I will proceed with smaller portions of the work as time permits with an overall year's time planned. Excellently done video and information,

Thanks for making this video, it was obviously a crazy amount of work. I had thoughts of doing this to my Nissan van (and it had literally no interior panels), but thinking about the amount of time and work caused me to procrastinate. Your video corroborated my thinking.

Great video. I’ve been contemplating doing something similar for my vehicle, but the work to received outcome ratio makes it hard to want to do. But I do have some experience in how sound and decibels work for radio waves, which long story short are just a negative inverse of sound the human ear can hear. But anyways a 3db chance is 2x the sound. So 73db is twice as loud as 70db. So to see a 3-5db chance appears as not much change, but in reality it can be quite a noticeable difference. Sorry to nerd out a bit but I enjoyed the video. Fantastic job!

I used to have an 07 CRV, and on the interstate the road noise was soooo loud. I can see this as a good "quality of life" upgrade - like you said, not dramatically mind blowing but enough to edge your comfort and conversations to where you aren't noticing the road noise in the foreground of your attention. Good work on this video, that's a lot.

Good job with these. Really change my perspective on sound deadening on car positively.

Greetings from New Zealand. Huge respect to you for your professionalism in putting this amazing video together. It should be the blueprint for anybody considering undertaking such work. I’ve done some sound deadening work in my Nissan Sunny many years ago and while it greatly reduced drumming noise the reduction in road noise although noticeable was not great. I later went onto to spraying the wheel arches with a bitumenous type of thick spread which helped massively with tyre noise but eventually resulted in accelerated rusting where there were gaps as water off wet road surfaces would stay in these gaps for a very long time. That was in the early 90’s. Here in New Zealand the road sealing is done using quite coarse stone chips making road noise a real issue. I’ve driven an identical Nissan in Sydney, Australia where the road surfaces are of much finer chips and the the interior noise in the car I was driving was so much lower.

Excellent work! One thing I think you could emphasize more is the pitch of the noise...the "after" clips had a noticeably lower average pitch than the "before" clips. High frequencies are being reduced much more effectively than low frequencies, which makes sense given the energy involved in producing the sound. The subjective improvement is impressive! Your meter is probably weighted to account for that somewhat, but the audio tells the story more accurately than the meter in this case.

I can't stand cars or car culture, but this was a fascinating watch on one of the worst forms of pollution from cars. It's also cool to see the same car I utilize.

I seriously appreciate the time and effort that you put into this. Thanks for the informative content.

If the dB meter can be set to show readings from, say, 20Hz to 5KHz, I think you'll see a greater dB drop because it looks like you've succeeded in reducing noise in this range. And that's a good achievement because our ears are more sensitive in this range of frequencies. Cheers.

Great work! Quick note - tires made a huge difference on my Ford Transit Connect. The stock Continentals were awfully loud (and ended up failing prematurely due to separating belts @ only 30k miles), and we got some Michelin Defenders. MUCH more quiet and comfortable. Also looking at installing some of this sound deadening material.

Actually if you have a higher end vehicle and lower end vehicle, you can hear the differences and I do own both, a Honda hrv and expedition, the honda you can hear the road and its loud in the inside, where the expedition is just all kinds of quiet and the seat comfort level is unmatched by the honda, this is a really good and informative video, thsnkyou.

Fantastic video. Love you showing the whole process!

Excellent video that is so educational. You did an incredible amount of work to show us all the installation steps and the final measured results. It is greatly appreciated. Thank you!!

I had a set of Bridgestone tyres from Japan (17") with foam on the inside, they were noticeably quiet compared to other tyres on the same wheels. Love the video, very interesting

I used three layers of Peel and seal from home Depot to make it as thick as the expensive stuff and it was still cheaper

This is the best video I have seen on sound insulation! I've debated on installing some in my current cars and SUV but i didn't know how much it will actually do. Plus now i know what the 3 layers are actually for. I don’t know if i will but its definitely nice to know actual real world results instead of just marketing numbers or what people think.

Awesome video. Subscribed! Fellow DIY er here. I think one of the factors for the big difference in DB after the closed-cell foam application might have been the butyl rubber sealing off the holes in the doors. I have sound-deadened 3 vehicles, and I noticed a big difference on the two that I sealed off the door holes vs the one that I didn't.

I think you may have noticed a larger difference if you held the meter in the other hand. Perhaps you were getting a reading of window noise which would be unaffected by your work. A now central location may have given more insight. Great video.

Thank you. For the amount of work, the result is fairly meager. It is good to know the limit of these sound products. I greatly respect your excellent effort. It has saved me and many others from spending a lot of time on an upgrade when the better answer is simply to buy a higher end vehicle.

This is amazing. I've been wanting a scientific incremental layer experiment for years! This is exactly what I've been looking for. You should also look into weather stripping and next time you replace your tires see how much of a DB drop new or higher end tires give.

i used the exact same materials in my 2017 Subaru Outback Premium this summer and I got similar results. Conversation is much easier and the interior noise is hushed more than the meter can measure. Maybe it's the pitch of the noise that changed; it's hard to describe but it's very noticeable. This was the first time I had ever used mass loaded vinyl under the carpet. I didn't glue or tape it down because the thick carpet will hold it in place. And I agree that it would be helpful inside the doors but almost impossible to install. It's too heavy, too thick and wouldn't conform well to the irregular surface of the back side of the door panel. I would like to eliminate more of the noise from the wheel wells and would like to hear from anyone who successfully used a rubberized spray exteriorly. Kudos for a well done video. The best one I've seen on this subject.

I like this video, you're very knowledgeable of the materials you use and how to install. Very strong presentation, not stumbling for words!

This is exactly the video that I needed. I kept looking for tires that are quiet. Thanks for this video