Water for soundproofing. Ideas and thoughts.

[JohnnyHolland]

Researching information about soundproofing ive found out a few things.


The lighter something is, the worse its acoustic absorbtion & reflective properties.

The heavier & Looser something is the better its absobrtion properties.

If its rigid, it will reflect and transfer the sound (vibrations, think how rigid a drum surface is)

I researched heavy industry acoustic blanketing and found it is essentially rubber, with its structure in complete dissaray.

This is Rubber |-|-|-|-|-|-|-|-|-|

This is acoustic rubber /^-\/`\-_\/^

It makes sense, as each rubber particle vibrates it absorbs the energy and dissapates it as heat, because it has no "Radiator" or outlet for the vibrations.

This led me to a very obvious deduction,

WATER would shit allll over acoustic rubber for its denseness & looseness.


My idea is to create 2cm thick bladders or panels structured within a cabinet walls, these would be filled with water, as a side benefit if your grow caught on fire the walls would help!


Anyway thats my idea, has anyone ever heard of this being used in this application or others?
Im not doubting the properties of the water but the job of building the bladders/resovoirs yourself!!



JH.

 

[JohnnyHolland]

On further thought they could be plumbed in to increase the capacity of your resovoir?

 

[Mr. Greengenes]

Water is heavy but not so loose, at least not in the sense that sand is, which is great for soundproofing by the way. When it comes to sound, water is almost a solid. But, it would work well with a layer or layers of air between the water, which would be good for the cooling no?

Stage one soundproofing is no air holes, second thing is non contact of the wall surfaces with staggered studs or something. Beyond that, adding mass to the walls and floors.

 

[JohnnyHolland]

Thanks for the response Mr Greengenes,

I agree that sand would be brilliant , liquids are of course the "loosest friction free" of all solid things , i guess what you mean is that its too close to itself in that the structure is continuous and constant? I guess in that way it would transfer some frequencies sand wouldnt.

Im thinking of when im in a spa, with no bubbles going and i try saying something to my gf sitting 3 metres away she cant hear it, the water seems to absorb most of my voice till their is a muted remenant.

Going back to your idea of layers inbetween, by placing any reflective rigid material on the outside of the water wall thingys, it would reflect the sound back into the water , I know air is terrible conductor of heat but i dont know about sound? I reckon a crapload of bubblewrap around ducting would double for cheap duct sound deadener though because its higher frequency waves.

JH

""As sound travels through a medium such as water, it gets absorbed - caught by the molecules within the medium. The medium actually changes some of the acoustic energy of the sound wave into heat. One way that this happens is that the acoustic energy of the sound causes the molecules of the medium to start vibrating. The molecules are at rest before the sound wave comes through. In order for them to start vibrating, the sound must be powerful enough to overcome the molecule's resistance to movement. The molecules must overcome the viscosity of the medium through which the sound is propagating. They do this by stealing some of the energy from the sound wave. The absorption in sea water is much greater than would be expected due to the viscosity of pure water. In addition to the absorption due to viscosity, some of the chemicals that make the ocean salty also absorb sound and convert it to heat. The final result of absorption is that as sound moves or propagates through a medium, its amplitude decreases faster than it would due to spreading loss alone. This is due to the loss of acoustic energy to heat.""
http://www.dosits.org/science/sndmoves/2b.htm


This makes sense, water cant vibrate, im thinking only heavy bass would get through water whereas heavy bass might not get through sand.


Hey how about a watersoaked blanked encased so it did not evaporate, theres an idea...?

JH

 

[statusquo]

I was under the impression that sound carried exceptionally well in water

 

[GMT]

yes water is 5 times more efficient at carrying sound waves than air is. On the other hand "no one can hear you scream in space". A vacuum is the best insulator of sound, and heat, eg. double glazing panels.

 

[ScrubNinja]

Dammit, yes I was going to suggest looking into vacuums as well.

 

[grow1620]

temperature can affect sound waves alot as well. I know that colder temperatures conduct sound much better, I think it's dues to the fact that atoms/molecules or whatever move or vibrate slower at colder temperatures therefore creating less friction or resistance on passing sound waves, where as warmer air molecules would be much more active creating more resistance...i hope that mostly made sense, I'm no physicist but that's my simple understanding of it..at least in the aspect of temperature.

ok scrubninja time to design us a "vacuum trap" made out of simple materials at HD

 

[ScrubNinja]

Haha grow, all I have is a toilet plunger and a bike pump, I'll see what I can knock up

Anyone know how much of a vacuum is in something like double glazed windows? Does more of a vacuum kill more sound? Hmmmm Would be very hard to implement methinks.

 

[Jnugg]

Sound travels through water much quicker tand farther then in air.

Never thought of using water as an acoustic sound suppresor but I do know that it can be used as a deoderizer....it's called the waterfall effect.

 

[Ipsissimus]

you can hear sounds for longgggg distances over water.

 

[ColBatGuano]

You know that sonar is used by submarines to detect everything around them? Using sound reflection, sonar creates an accurate three-dimensional portrait of the undersea world--until it goes so low that water pressure stifles sound. That means it isn't the water, but the pressure which blocks sound. In a bladder, the water can easily change its shape to conduct sound. Because there is only the pressure of the air around it to prevent that, it wouldn't be much more effective than a wool blanket.

Interior foam and/or wood baffling has been the choice of studios and musicians for years. Baffling works better than single surface blockers because it diffuses sound before it hits the exterior surface of the room. It causes the sound to bounce around in different directions. Every time it bounces, and changes direction, it loses amplitude.

Baffling works against air movement, too. Microphone windscreens diffuse the force of the wind across the mic's diaphragm, reducing or eliminating its "noise" in doing so.

Low frequency sounds travel through objects far more efficiently than those in high frequencies. It is because they travel through a medium much more slowly. It is why you can always hear (or feel) the bass pumping out of the car next to you, but not much (if anything) else.

 

[Ipsissimus]

yes, but the sound is being generated IN the water. ever swim underwater? you can't hear squat of what's going on above the water, because the water is reflecting the sound, not absorbing it, or transferring it.

 

[ColBatGuano]

yes, but the sound is being generated IN the water. ever swim underwater? you can't hear squat of what's going on above the water, because the water is reflecting the sound, not absorbing it, or transferring it.

That is simply not true. Maybe for you it is, but I can hear a lot of sounds from the surface when I'm underwater. In fact, the closer I get to the surface, the more likely it becomes that I will be able to discern spoken words. I remember being at the community pool as a kid, and testing out how the sound of the music they blared overhead would change underwater. My friend Brenda and I even used to play games to see if we could tell what the other was saying. A thinly-filled bladder would have even less water in it than the amount in-between my ears and the surface when I'm swimming.

I should clarify:It is true that the surface of the water does reflect sound. Anything you put in the way of the sound wave will do that to some degree. A set of water-filled bladders might very-well work, but would they work any better than a furniture blanket or a sheet of foam? Probably not. Why bother with all that crap when it won't do any better than cheaper, easier, less strenuous methods?

 

[Ipsissimus]

as a kid, you noticed how sound was muffled and distorted underwater. that's what I was saying, I didn't mean to say you can't hear anything. everything sounds far away. the sound that does transfer to the water, travels really far and well. (that same faint music can be heard very far, at that faint level). have you noticed how ridiculously loud and clear sound is that is generated in the pool, vs. outside? try cracking your knuckles underwater vs. out of water. people sound like they're a few rooms away, at best. to me at least. on a body of water you can hear people talking thousands of feet away. if the sound travels a long distance above the surface of the water, then it seems logical that is not being absorbed by the water. if water is both reflective of sound as a surface, as well as highly conductive of sound as a medium, it seems like one of the worst materials you could use to sound proof a room.

 

[JohnnyHolland]

Hehe well you guys cleared all that up! thanks very much.

JH

 

[JohnnyHolland]

yes water is 5 times more efficient at carrying sound waves than air is. On the other hand "no one can hear you scream in space". A vacuum is the best insulator of sound, and heat, eg. double glazing panels.

What would be a cheap alternative to double glazed glass? as far as creating a vacuum would go?

JH

 

[Ipsissimus]

JH - much research has been done in this area. Try googling "sound proofing". Checkout http://www.soundproofing.com/. Try drywall on both sides of your wall (if interior), or double up and leave an inch of air inbetween. Spray on cellulose works well too.

 

[GMT]

Creating and maintaining a vacuum is difficult and expensive. The wondow industry have brought the costs right down due to the economies of scale they achieve. I think you'd be very hard pressed to outdo them at that game in your garden shed. On the other hand the music industry uses Rockwool to "catch" sounds that would otherwise bounce off hard surfaces. A layer would certainly muffle any noise, though wouldnt stop vibrations from being passed through the floor. You have to look at everything from the way its in contact with the floor (and type of flooring) to how you hang anything that vibrates, like fans, before even considering moving to additional measures.

 

[rrog]

Spray on foams are, in fact, a bad idea with sound proofing.

Mass is a good thing, and drywall is cheap mass.

Decouple the noise-side of the wall stud from the wall stud with staggered studs, double studs or resilient clips.

Insulate the air cavity with standard fiberglass.

If you add more mass (second layer of drywall) you could dampen the drywall with greenglue: http://www.soundproofingcompany.com/library/articles/room_within_a_room/