Sound Deadening a Car Where It Actually Makes a Difference!

Using sound deadener in a car will definitely make the sound system sound better but does using sound deadening mats in a vehicle actually make it quieter inside the cabin? Ill talk about that and also where exactly to install the sound deadening material in the vehicle to take full advantage of the sound reducing qualities.

Ill also touch on the difference between the mat insulation like second skin or dynamat versus a spray on sound deadener like boom mat spray to Reduce unwanted road noise and vibration, even in hard-to-reach places.

Links to the soundproofing products I talk about in this video. All links are from Amazon and are affiliate links which helps my content at no extra cost to you. Thank you!

[soundproofguide]

Links to ALL products I recommend in the description of this video!

[darrenschmitz]

On your comment of insulating the floor of the car, I just put standard house floor underpadding underneath the carpet in a cheap econobox. It was so effective people actually would comment on how quite the car was.

[Jay-jefc]

I also did deadening on the roof. it didn't help much in normal day driving. but much better when it rain. It also help reduce heat from the sun.

[hkhatri]

Your experience over the years of making these videos is definitely showing up! This was much better put together.
Thanks.

[fullfacejosh]

really great overview of different areas. The only thing I'd add is specifically in hatchbacks I have found doing the "trunk" area can make a huge difference since it's really inside the cabin vs. the mostly uselessness of doing the trunk in a sedan.

[Mcfreddo]

I have an 'entry level' vehicle for getting about and yes, it's quite noisy. Thinking that it's not good for my hearing. Been on my mind off and on for a long time to insulate it than it has. This video has spurred me on. Remember: No project's too big to start! 😂😢😂

[philsowers]

TLDR: Under Hood, Under Wheel Liner, Doors, Floor. Not the Trunk.

[billiebobbienorton]

I kept my late husband in the trunk and the ride became soooo much more pleasurable and the sound changed dramatically. Had to remove him when decomposition started.
Seriously.

[LocalAutist]

the trunk is also dependant on the car. Newer cars are usually pretty stuffed with liners and interior/trim. Older cars, especially wagons, can benefit a lot from it. My car specifically, Volvo 740, has a solid rear axle and (iirc) no factory insulation and the trunk actually uses a lot of wood for the trunk interior, sound deadening the trunk area makes a HUGE difference on my car specifically, mainly around the wheel wells and where the axle mounts to the chassis to be specific.

Potential seal breakages and where stuff mounts to the chassis are areas you'll see a lot of improvement, suspension mounts like I mentioned above.
If your car has a tow hook then it could (theoretically) make a big difference when pulling a trailer considering they don't have suspension most of the time so your car is gonna absorb a lot of the road vibrations

[JS-wcxs]

A fabric headliner with a polyfill backing added (in addition to adding cheaper sound deadening material) is a great way to lower the road noise. Yes adding sound deadening to the floor, (and)doors, and adding closed or open cell foam in between the outer and inner skins r also inexpensive ways to reduce road noise. I've personally been able to reduce my ambient road noise by at least 3db. Also I'm only halfway done with my vehicle so hence y I say at least. (It's been 3db already and I'm not finished yet. I still have 2 more doors and 2/3 the floor to add material to).

[myma]

Best of all is the trunk of cheap/barebone hatchbacks/estates because it's often just steel sheet down there. I once had a cheap mk.1 yaris and it made a world of difference just with the area aft of the rear seats; it muted a lot of exhaust rattle and road noise for very little money and effort. It's also really easy to cover the rear wheel wells in hatchbacks from the inside.

[monkda]

I understand that the trunk can be not entirely worth it, but for me it was worth looking at! I have a 2010 corolla s, and under the carpet where the spare cavity is, there is nothing! Its just plain frame. I added adhesive back cat scratching carpet and added missing plugs to the drain holes and at fwy it reduced droan and lessened the bang over speedbumps quite a lot!

[JOHN_WICK_IS_SICK]

that last comment about left over clips hits home. i can even count the number of times I've just said "F it" and left plastic parts off my car because of the hassle of those clips.

[zelowatch]

Sound deadening doesn't do much besides stop rattles. To stop road noise MLV or sound absorbing material is more important

[tonyleung]

The other cheap and effective way is to spray truck bed liner to your fender liner (only the plastic part)
It does reduced high pitch road noise

[Aljoeharper]

It's a double edged sword putting it under the hood, yeah engine sounds are reduced cool....but engine sounds are reduce....meaning you're less likely to hear a potential major issue before it becomes major....example Car starts to misfire.

[sleekitwan]

Easiest tip - never mind the underfloor work. That’s hard, and not for everyone. Two negatives for it - hard and water absorption. Maybe the foam you use is closed-cell, maybe it’s not, how would you know before buying it (sure, there’s a description by the vendor, I know). Add a second set of floor mats, or some kind of under-mat padding, eg same underlay as for carpets at home. One big issue hardly mentioned, is fire. Hands up all those who flame-test the stuff that says it’s ‘fire-resistant’ themselves after they buy it. I got a shock, had some special foam pads for a loft, flame-retardant it’s meant to have…I lit it with my hob igniter flame just like the ordinary foam - both were self-perpetuating to a degree, once they ignited. But, floor mats, is my tip. Remember, these are the biggest flat sections of your interior, along with the roof and the door panels. It’s not just about stopping large flappy panels from undulating, it’s also about absorbing lots of little echoes that otherwise ping-pong around. But, good vid, thanks for these insights on other stuff. Take care all, and don;t be afraid to use earplugs for long lonely journeys, that works too (question for discussion: is it worse or better, to use the likes of Apple earbuds when driving, for your ear protection? My brother and I kicked this around. It is alarming how loud you turn the stereo in the car up, when going faster than say 50mph/80kph. Earbuds block noise, but do you end up turning them up too, so much it’s bad on a long journey? And, the earplug/earbud method, makes you slightly more ‘deaf’ to vehicles in close proximity. Anyway, points to ponder.)

[robertSharp-ss]

Excellent mate. Thanks for your advice which I will follow later today. Very clear explanation, great work.

[epicraptorman]

I have a hatchback/lift back. So sound deadening it's trunk is a lot more salubrious than a typical sedan

[MrPooh]

Depending on the car you have a lot of sound comes from the trunk especially the spare tire location. if you dont do the trunk at least insulate the rear deck as trunk noise can enter the cabin thru there. Dont take off the wheel well liner, just Clean it real good and spray many layers of under coating. I noticed a reduction of road noise and liner remained in place. So far the undercoating is still in place as it was made to withstand outside conditions such as when installed on under the car.