How To Make a Speaker
A homemade speaker using a plastic cup, business card, wire, magnet and some Lego blocks. I built this speaker from scratch; I was surprised of the quality of the sound. Updated! (6/14/2007)
Source: http://www.josepino.com/?howto-speaker Tags: diy
homemade
science
projects
audio
I doesn't look like a high-tech speaker but it works well. I didn't expect a high quality of the sound from this made-from-scratch speaker but it performs very well, better than I expected.
A speaker is just a magnet, a coil, frame and a cone or any material that can make the air vibrate. Here is the bill of materials that I used to build this speaker:
Taken from http://www.josepino.com
1 Magnet (neodymium magnet works great)
1 Business card
Wire 32 or 34 AWG (you may use 30AWG)
Paper bond
Tape
Glue
Scissors
Ballpoint pen
Lego bricks or wood.
Ruler.
Cut two long pieces of paper vertically, half inch wide. (0.5 inches by 11 inches).
Roll one strip of paper over the magnet. Use some tape to keep it but DO NOT put tape on the magnet. The Cylinder needs to be removed from the magnet, so do not tape the paper to the magnet.
Roll the second strip of paper over the first one. Do not glue or tape each one with the other. Roll it individually.
Use tape to keep the paper as cylinder.
Using the ballpoint pen, Draw three lines on each side of the business card. There is no exact measure but try to draw the lines at least half inch away from the corners (0.5 inches)
Fold the business card using the lines as reference. The lines will help to fold it.
Remove the magnet and glue the paper cylinders at the center of the business card. Using instant glue or hot glue works ok.
Once the glue is dry, put the magnet back inside the cylinder and start making the coil.
I do not recommend to use wire AWG 30 as it needs a lot of loops. Using AWG 32 or 34 will need about 40 to 50 loops. After you finish winding the wire, use some tape to secure it.
Do not try to make the coil without attaching it to the business card, it is an almost impossible task.
Make the frame approximately the size of the business card and not higher than one inch.
I used Lego bricks because I had some handy. Wood may work better. Try not to use any metal that can be attracted by the magnet.
Put some glue on the magnet when it is inside the cylinder. On this step, Hot glue works better than instant glue. Be sure the glue doesn't touch the paper cylinder.
Assemble the speaker and let the magnet to fall and glue itself to the frame. It will allow to have the magnet exactly on the center of the coil. Wait until the glue dry.
Once the glue that attach the magnet to the frame is dry, remove the business card and the coil. Try not to disturb any piece on the frame or the business card.
Now, remove the inner cylinder. Is ok to break it as it will discarded. Try not to damage the secondary roll [or paper cylinder].
The last step is to put back the coil to the frame. The coil should not touch the magnet and should move freely.
I did connect my home-made speaker to my laptop and here is how it sounds like:*
WAV File, 1MB
6/17/2007 Update:
I did a modification to my homemade speaker and it improved the volume of the sound. A simple disposable [plastic] cup amplifies the sound mechanically. The sound is amplified because the resonance of the plastic cup.
Once the "Speaker" is assembled, cut a hole on the business card. (see next photo)
Glue the coil to the bottom of the cup instead of the business card.
Glue the plastic cup to the business card and that's it! Now it looks like a real speaker, a home-made speaker, just built from scratch.
How it works?
The coil generates a magnetic field when electricity is applied to it. The magnet attracts or repels the coil and makes it to move. The vibration generates the sound that we hear thanks to the air.
Most of today speakers have a resistance of 8 ohms. This homemade speaker may have less than 8 ohms and may not be able to make loud sounds but basically it shows exactly how it works.
Using different materials, may cause the sound to change, even to make it louder. I will work on another design to find which one works better. I will work to make an easy and better design...
... someday. That day was August 6, 2007. I created a
Hi-fidelity Homemade speaker.
Check it out!
3/13/2008 - Update: If your speaker sounds Horrible, check:
The wires should move freely.
The cards should be completely glued to the cup.
The coil have no loose wires. Try to keep the coil tight enough and secure it with glue or tape. Loose wire may vibrate and cause distortion.
The coil should not touch the magnet. Try to make the coil wider. Also, the coil should not touch the LEGOs.
The sound is too quiet? No sound?
Be sure the coil have at least 50 turns or, if you have a multi-meter, more than 7 ohms.
Adjust the height of the coil in reference to the magnet.
Use only neodymium magnets.
Some personal or portable audio devices doesn't have enough power to drive a speaker. Try many audio sources if you get no sound or the volume is low. Also, you can try this simple circuit:
Mini Amplifier with LM386
***WARNING*** DO NOT use AWG 24, 26, or 28. You need to use AT LEAST AWG 30. The wire should be isolated! Again, it should have a coating. Do not use any other kind of wire as it may short-circuit the audio output.
1The WAV file was creating using a second computer, recording directly from the microphone, one inch away. The sound from the homemade speaker was not loud enough because it was not connected to any amplifier or any driver.
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09/05/09 - 02:51:12 need help from wrote: if you want to make this speaker battery powered and have it running from an ipod how would you go about it
09/09/09 - 17:26:56 sammy semones from upton wrote: i think this is a great idea for a science project
09/09/09 - 17:39:51 José Pino wrote: Thanks Sammy, but I had to remove your last comment. Please be aware that offensive or racist comments may get you banned from this website. Doesn't matter if your change your name or location.
09/16/09 - 21:21:50 Basim from Kingdom Of Saudi Arabia wrote: What does AWG stands for?
09/16/09 - 21:25:33 José Pino wrote: AWG stands for American Wire Gauge, and it is a standard used for denoting wire conductor diameter. The system is counter-intuitive, so the lower the AWG, the thicker the conductor.
09/30/09 - 11:06:02 Arif tariq from Egypt wrote: nice idea thanks
10/01/09 - 17:29:06 bill from hill wrote: this project i made s a a+ project all u need is paitents
10/08/09 - 14:46:08 matt from detroit wrote: hey i wanna try this some day i hope it works i would like to if i could buy one thats alredy made you could reach me at 3134697540 my brother blaze will pick up because he runs a studio for $10 an hour if u want call u will be able to sweng by and check us out
10/10/09 - 04:18:31 inah from tarlac wrote: how does it totally works when we need electricity?there's no connection..
10/11/09 - 00:53:46 joe from kansas wrote: How do you connect to a music player or computer so it can play the music?
10/11/09 - 18:56:26 Jason from Lebanon wrote: That is pretty cool, i might try it later.
10/26/09 - 16:18:11 Hrida from bangladesh wrote: dude it was completely stunning . after making da speaker i feel like a scientist!!!!! thanks
11/04/09 - 17:57:59 Nick from Phoenix wrote: Where do i make the connection to connect it to an iPod, radio, or laptop?
11/08/09 - 08:54:05 pawan from indore wrote: a very good model
11/10/09 - 08:14:23 jay from 83655 wrote: will a 16 wire work to make a speaker?
11/10/09 - 08:16:02 José Pino wrote: No way.
11/17/09 - 08:40:54 iraj from philippines wrote: thanks..really of great help for my project..
11/19/09 - 02:19:09 Nick from Phoenix wrote: WHERE DO I MAKE THE ATTATCHMENT FOR AN IPOD INPUT????
