Welcome to, The home of the PCCA => General Help- Ask the Experts... => Topic started by: C. M. Wolf on August 30, 2015, 09:36:55 AM

Title: Sound-Deadening..
Post by: C. M. Wolf on August 30, 2015, 09:36:55 AM
Hello Everyone..

I'm responding to a shout that I noticed here.. Sound Deadening on cars.. there's basically 2 ways to go about this, the actual reason for the sound-deadening is key.
1st.. Would be insulating for temp/climate reasons, which also supplies some sound deadening quality too(certainly can protect the car & passengers from the elements, hot & cold). Making sure all the window, door, & vent seals are in very good shape is a place to start, Then making sure all the vehicle's undercoatings are in excellent shape & fairly fresh also helps, this reduces any sound-vibration also. Even applying this exterior under-coating to the body surfaces that are covered with upholstery/carpet helps(just make sure it's the 'rubberized type' that dries completely to the touch so you're not cementing the carpet to the body making it too hard to ever replace). Then getting a good neoprene type foam padding that's 1/4" to 3/8" thick under the carpets adds insulating factor & sound-deadening degrees also. Any carpet padding that's added does need to be custom fit to the areas it's applied. This foam padding can be contact-cemented directly to the areas of carpet that need to be 'movable' such as the area that covers the spare tire.
Also a very thin(1/8" to 1/4") spraying of "Urethane-Foam" can be carefully added to the inside surfaces of most of the passenger compartment panels.. but this spray-foam can be expensive and hard to find someone to do it correctly as the right type requires a special catalyzing sprayer when it's applied.

2nd'ly.. Would be to strive for 'sound-deadening' quality by applying the under-body-coatings to all unseen/uncovered interior surfaces of the car, then contact-cementing a layer of the above neoprene-foam to those same surfaces(as long as these layers don't interfere with the proper operation of the vehicle or it's intended moving parts(such as windows, vents, doors, lights, wiring, hatches, etc)..   

I wish to strongly note here.. that putting in a "Boom-Box" sound system or any sound system that strongly vibrates the car's surfaces most certainly WILL do DAMAGE to the structural integrity of any vehicle. If a sound system is strong enough to vibrate the car's surfaces, it's eventually going to vibrate the very welds apart that hold the vehicle together,(this can destroy a "Uni-Body" vehicle and render the vehicle into a "Death-Trap" rolling down the road.. and that's aside from the physical damage it's doing to your hearing and the hearing of any passenger in that vehicle).
(Btw, if anyone might need proof of the catastrophic damage a strong sound system can do to a vehicle, just let me know.. a very good friend of mine owns a body shop & I can supply pics of the popped welds that a too strong a sound system has caused on the structural areas of a vehicle).. Needless to say, I would never buy any vehicle that had ever had a 'boom-box-stereo' in it, not even for half the actual price it might have been worth.


C. M. Wolf
Title: Re: Sound-Deadening..
Post by: popbumper on September 07, 2015, 06:47:06 PM
As someone who has severe ear damage and lives with chronic tinnitus and hyperacusis (on short term disability from work currently), consider me the POSTER CHILD against deafening stereo systems. These fools that are pumping out 100+ dB noise levels on themselves are gonna find some real misery in their lives one day. Consider your hearing as a bank account that you make withdrawals from each day. Once your account is empty, you can't make any deposits. Period. Simplest way I can put it.

If you think you are immune/impervious/or don't care, go ask a veteran who lives with tinnitus from gunfire and explosions. We're all gearheads here, we love our cars, but remember - it can happen to you, and loud noises are silent killers. I learned the hard way. DON'T do it to yourself.


Title: Re: Sound-Deadening..
Post by: Wittsend on September 07, 2015, 11:36:25 PM
I'll second what Popbumper said. Of all things it was a Christian concert (Any Grant) where I first experience hearing loss. And I wasn't planted directly in front of the speakers either. The second incident of hearing loss came from a ringing circular saw.  My blade was dull and the wood hard. I was in a hurry and just persisted through cutting a stubborn 2X4 even though the ringing blade was very unpleasant (and I'm not exceptionally sensitive to loud sounds). It took less than 10 seconds to do the damage. It's not that I can't hear, but I sure can't hear like I use to. I'm also acquainted with a professional sound guy. He told me that years ago they found that men had hearing loss in their left ear and woman in their right ear. The cause? The sound of wind driving with the windows open. Where as today we had A/C we also have deafening stereo system.

I taught Television Production for a living. And as the economy faltered I was arm twisted into teaching a beginning audio class - if I want to maintain my class load. This was not my area of expertise and I had to study a lot to met the class criteria.  I found it amazing the rate of hearing loss in the industrialized world. I spent nearly an hour on the subject, its causes and prevention.  I hope they were listening.

Can you hear me now... Can You Hear Me - NOW?
Title: Re: Sound-Deadening..
Post by: dga57 on September 08, 2015, 08:49:31 AM
I generally blame 35 years in industrial engineering for my hearing loss but it was helped along by years of playing in bands.  As has already been said here, the key is to protect your hearing!  Even with all the OSHA approved safeguards, your hearing is still vulnerable.  I have the hearing aids to prove it!

Dwayne :) [size=78%] [/size]
Title: Re: Sound-Deadening..
Post by: 76hotrodpinto on September 08, 2015, 12:26:04 PM

I was a "rave" dj for over 20 years, and built/operated large sound systems for the edm community. I always kept a big jug of earplugs with a free sign on it next to my little dark corner of the venue, and RARELY did anyone take them without me prompting them. In the "scene" we had these crazy people that we called speaker freakers. They would get right up front of the stacks when they danced. Often I would post a sign the subs to warn them of the extremely high db levels, but they thought it was worth the risk and/or the signs would just rattle off after a couple minutes of shaking. After I started using servo drive subs, I HAD to fence them off. The servo subs would do 17hz at 141 db. They would blow empty water bottles about 10 feet away on the floor.

I'm not the sound deadening expert, but if you want to shake a car apart... from the outside ;), I got you covered!
Title: Re: Sound-Deadening..
Post by: popbumper on September 08, 2015, 05:51:35 PM
Thanks for adding your personal experiences guys. This is such an underserved and little mentioned topic (the dangers of sound). To think of all the industrial work in the past when men were building boilers for locomotives, doing steel work on ships, autos, etc., and the amount of racket they were exposed to for years. Sad to think it's a resource you can "maintain"....but so fe knew then, and so few care now.

76hotrodpinto - 141 dB at 17Hz....dear God, that's a massively long wavelength and I can see why it blew water bottles down. People don't understand the dangers of sound energy just as much as they don't understand the destructive power of UV rays that can cause cancer, and do, contribute to the formation of cataracts later in life. I know because the eye doctor says I have about five more years before surgery.....

Title: Re: Sound-Deadening..
Post by: 76hotrodpinto on September 08, 2015, 11:03:35 PM
We ran low on voltage before I could max it out, still had a little headroom. Never ran it at a show that loud, just at system checks. It would blur your vision and make your stomach queezy.
Title: Re: Sound-Deadening..
Post by: Reeves1 on September 09, 2015, 06:11:02 AM
My car is going to be loud. I put sound proofing on the full floor & fire wall.

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Title: Re: Sound-Deadening..
Post by: pinto_one on September 09, 2015, 09:34:43 AM
Did mine that way Reeves 1 but I used the 1/2 felt with the Alum backing from JC Whitney , cut and fit and used Alum tape to hold it all in place, I also use Rino truck bed liner painted on thick on the floor, after I had to replace the drivers side floor area due to a windshield gasket leaking , so if any one does this make sure you DO NOT have any leaks in the car , the insolation will hold the moisture and rust things out big time , I also sprayed undercoating inside the doors to sound proof any road noise from there , I also done the back if the seats in the trunk area and the rear tray area under the speakers also , I wanted a very quiet Pinto, and the overdrive slowing the engine down on the hwy makes it very quite, only at red lights the only thing I hear is the ringing in my ears from tinnitus I got years ago working in tow boat engine rooms ,   ???, and to you young pinto guys out there protect your hearing AND eyes , its bad when us old pinto people cant hear shizod or see shizod,  :o