Instructables
Picture of Harnessing sound power
Everyone is talking about using solar panels and wind turbines to Go Green however those are far from the only sources of renewable energy; one that is almost never spoken of is sound.
Although it does take a fair amount of noise to generate a descent amount of electricity, if you think about it, say you were to harness all the noise from a football game or the hustel and bustel of a large city, by the end of the day you have a lot of power energy. And, while it is of course far from the solution to the plethora of climate problems that faces us--being as impractical and inefficient as it is--the notion of converting sound into electricity is nevertheless in my mind a very neat and fun concept to which very little attention is given.

The things you will need:

2 wires
1 volt meter
1 speaker (the bigger the better)
 
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Step 1: Wiring the speakers

Picture of Wiring the speakers
The whole process it quite simple. The first step is to attach wires to your speaker. Your speaker may already have wires attached and if that is the case go right onto the next step.

Step 2: Hooking up the speaker

Picture of Hooking up the speaker
The next thing to do is to connect the your positive and negative wires on the speaker to the volt meter contacts and switch it on.

Your done!

Step 3: More

To increase its output you can place the speaker up against a speaker playing some music or if you happened to own a jet, you could strap it onto the engine and make some serious electricity!
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gmartin8881 month ago

mmmm, it makes me think, how about collecting electricity from silence...meaning from sound waves that we can not hear...

arjunmenon4 months ago

I dont understand. How by connecting the speaker wire to a multimeter set in volts, will show a voltage?

rsingh796 months ago

can you light up a 1.5 volt bulb with this/how loud it needs to be to light up a 1.5 volt bulb

Applebohn (author)  rsingh795 months ago

You certainly wouldn't be able to do so the particular setup in this Instructable... but that hardly means it's impossible! I'd recommend trying to light an LED (as they have a very low power draw) and testing out a number of differently sized speakers for generating electricity. My intuition is that a large generator-speaker would be ideal, as it would have a corespondingly larger stroke (the amount the surface of the speaker rises and falls when making sound). If you give it a go, be sure to post your findings!

I'm very interested in making sound energy sufficient enough to produce great amounts of energy. I was wondering is there a way to amplify the power produced from sound? If not do you think something like that could be built?
DoctorDv1 year ago
Hi!

My science fair involves an idea similar to this. I am going to see how much electricity is produced by the speaker when "x" amount of decibels are provided. I was wondering if you have any suggestions as to which type of speaker I should use and if it should be big or small. Thanks for your help!

-Doctordv
tatay663 years ago
Unlike one commentary this is a sound idea for the most part. Anybody who has a shake flashlight and a little electronics background knows you can reverse engineer most things. Try using a large paper plate as your sound collector. Also if anyone here has seen the exalted belt generator for 3rd world country use you should recognize the same electrical as the speaker here. So yes this would work in some functions if you rethink your uses. PS you can find that Ribbon generator on you tube. http://www.youtube.com/watch?v=dZ0v-CK63-4&feature=player_detailpage (be sure to observe this guy uses two coils from speakers to make this work)
meghatoks3 years ago
speakers emit sound ..... how do we get to gather it ???
Applebohn (author)  meghatoks3 years ago
Yes, speakers do emit sound but as is the case with all electromagnetic devises not only can they consume energy, i.e music blaring out a speaker or a motor spinning, but if done in reverse they generate power and speakers are no exception. This is the basic principle behind wind turbines and it too can--in theory--be applied in speakers to harness energy (although it is not nearly as effective). Read the instructable!
MaXoR Applebohn3 years ago
Doesn't sound travel better through water? What if water was replacing the air in this idea? Air is just a liquid when it comes to physics......
Air is not a liquid mate, it's a fluid. Air and water are both fluids, but they aren't both liquids.
You're right, I used the wrong word. Thank you for being ever so vigilant sir.
gmabe19833 years ago
also this idea was also used by Tesla to prove a point
Bando_Red4 years ago
How well do you think gunfire would work with this?
Applebohn (author)  Bando_Red4 years ago
Great thought, it never even occurred to me!!! With gun shots being so loud, all you'd have to do is set this device up at a large firing range and you'd be in business!!!!!! Yet sadly, as for tapping into all that energy wasted by firearms, it could be more difficult to do so than with say, an excited crowd at a stadium. Due to the fact that gunfire is typically is in short loud bursts, you would be left with incredible short, sporadic bursts in voltage. But hey, its still sounds perfectly doable. For starters you could add an inductor to your circuit in order to help create a more consistent voltage output and then all that's left to do is strap it to a machine gun and pull the trigger!!! :D
I think what you meant to say is a capacitor, not an inductor. Since you have an oscillating signal, an inductor would create high impedance until you had current flowing in one direction for a long period of time. A capacitor, on the other hand, would gain impedance as it collects charge and release that accumulated energy when the voltage drops.
A moving voice coil creates alternating current. Capacitors filter out AC electricity. You'd have to run the 'wild AC' from the coil through a rectifier before a capacitor would even out the current to cleaner DC.
Good point. I forgot about rectifying when I responded to this last year.
Applebohn (author)  Great Wight Ninja3 years ago
whoops, your quite right!
How about placing this in the engine compartment of a vehicle? Or on a larger scale, places of industry/vehicles that "generate" noise.
4sc4n103 years ago
Sometimes you have large signs printed on plastic fabric, mounted on sandows. Just add a voice coil and you've got a huge transducer !
Would using a microphone produce more energy than a speaker? Are they not designed to be sensitive to collecting sound? You might be able to collect a wider range of sounds. Maybe a microphone is just a speaker in reverse much like you've done here.

Here's a random link I googled: http://www.marktaw.com/recording/Electronics/MicrophonesSpeakers.html

I think the cone/funnel idea is an excellent one for increasing the sound collected by a single speaker. I would definitely expect it to increase the power output.

I'm going to try this today.
Well it depends on what microphone you use some types of microphones only change resistance and do not convert sound to voltage...
microphones and speakers are built the same, the only real difference is that speakers are made of thick material and microphones are made of very thin material.

Speakers are thick so they can produce louder sound.
Microphones are thin so they can be vibrated easily (more sensitive to sound)
Applebohn (author)  morgangalpin3 years ago
That's a very interesting idea! I bet you're right, it would make perfect sense that a mic would generate more electricity than a speaker!
MaXoR3 years ago
LMAO.... you guys aren't stepping back to look at this whole theory..... all of you who think this has potential, will cry once they realize that even the most efficient set up like this, would be very watefull, and inefficient.

Don't get me wrong, I love this idea.... there is just a reason it's not being used today.......
Cool idea, did you think about using a very large "speaker cone" attached to your speaker coil?
Applebohn (author)  omgitzstegman4 years ago
Na, hadn't thought of it, but now that you mention it, it makes perfect sense. Focus the sound on the speaker... good idea!
I don't really mean "focus" the sound but more like a large rigid surface that you could even attach to the regular speaker cone. It would act like a larger piston to move the coil. BTW I'm not sure how you could rectify that AC into some useful DC for your LEDs. Good luck!
use a bridge rectifier, and run it through a smoother circuit. I run LED's off generated AC, converted to DC..... good as gravy!
I wonder about using a "bank" of speakers... several in series or parallel to capture the entire range of sound... several octaves in both directions from human hearing... placed into a busy "city" environment... I'll bet you could generate 24 volts and up to a couple of amps. Worth a try? How about a long "wire" mic next to busy trains and freeways? Or what about capturing the very rumble of the earth in ultra low freq piezos? the possibilities are endless. Mankind soon will be groping for such salvation technologies. I'll bet my 57 years on it.
MaXoR mortso3 years ago
sorry for another one.... Mankind will ALWAYS have to take the cost of harnessing such power, against the gains you receive. How much will they have to spend, to gain how much energy?! I like others on here would like to see a scaled up model put to actual tests. I doubt this theory would be anywhere near to an "answer" for our energy crisis.
MaXoR mortso3 years ago
I have a question.... where did you get your voltage math from? Just pulling numbers out of the....air?
Applebohn (author)  mortso4 years ago
YES! That would be awesome!!
...and let's not forget the whole range of powerful Cell, Radio transmitters out there... basically putting energy into the air in a certain spectrum— like sound! How about capturing that energy as a pure energy source... no "listening".. just watts of RE-captured power. just "another" thought! lol
Applebohn (author)  mortso4 years ago
LOL
Well guys I did some more research in it and what happens is very disapointing. There is a ring of coild which when receives electric input gets mangnetized and moves away from the magnet.
In his case the guy was using sound waves from another speaker to vibrate that coil. Whenever copper coil and magnet come close the magnetic field excites electrons in copper coil and current is produced. Those who know how electromagnetic works will understand immediately whats going on. To cut long story shot this idea is busted. Switch to wind turbine its more affective. However if you are really interedted in harnessing sound lookout for acoustic systems which use sound to generate waves in helium. .......
Actually, the sound energy is being used to power the speaker, like how a microphone works. I believe speakers are magnetically shielded, or at least not a large enough magnet to actually influence stuff around them through their case.
Applebohn (author)  talhakamran20063 years ago
What the heck is "this idea is busted" supposed to mean?! It does work, not with great efficiency but I was proposing it as a concept project, for fun, not a plan to save the planet. If your still a cynic I suggest you check out this article about Daniel Wang: http://findarticles.com/p/articles/mi_hb242/is_201009/ai_n55071644/pg_2/
Sorry my friend, wrong words came out. Actually me and my fellow contrymen are desperate to make electricity in our backyards. You can imagine how would you feel if you dont have electricity at house for 12 hours a day and you live right on the equator.

Please accept my sincere apology.
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