How to Build a Simple Speaker

In this Instructable, I will show you, step by step, how to build a speaker.   To build a speaker, you need very little building skills, and just a little bit of background knowledge.  Building a speaker is a fun, cool, educational, and rewarding project!

Speakers are used in everything around you.  From your phone to ultrasound machines to singing toothbrushes - they all have speakers inside of them! 

Step 1: A Little Technical Background Knowledge on How Speakers Work

The speaker I will help you make is called a moving coil driver or a dynamic driver. A dynamic driver consists of a stationary magnet fixed to the base or bottom of the speaker housing or basket. Sitting around the stationary magnet is a moving coil, which is attached to the output of whatever device your speaker is connected to. As you play music, a current is run through the coil creating an electromagnetic field around the coil. This current is constantley alternating and reversing the poles of the electromagnet. Since opposite poles attract and like poles repel, the coil, attached to a diaphragm, or thin layer that vibrates the air, vibrates as the coil is attracted and repelled and attracted and repelled and so on.

Sound is created by the diaphragm vibrating the air in front of it. Basically, when the diaphragm moves out, it compresses the air in front it. Then, the air in front of the air in front of the diaphragm is compressed and so on.

Since air has weight and it is accelerated by the wave of compressed air behind it, force is created (a push or pull). Once this wave finally reaches your eardrum, this push (force), pushes you eardrum in and turns that wave into something your brain can interpret and you can hear.

Step 2: Acquire Parts and Tools

For this project you will need 7 parts. 

1) 1x Bowl (any size works) - Can be Found in any Grocery Store or CVS 
2) 1x Plate (should be about the same diameter as the bowl) - 
Can be Found in any Grocery Store or CVS
3) 1x Role of 30 or Higher Gauge Insulated Magnet Wire (the more the better) - Can be Found in Any RadioShack or on Amazon
4) 1x Magnet (I am using a 1in by 1in N50 grade neodymium magnet which is dangerously powerful but louder - so be careful) - Can be Found at True Value, Home Depot, Lowe's, and Amazon
5) 1x Index Card/Sheet of Construction Paper - Can be Found at CVS or Michael's Arts And Crafts Stores
6) 1x Role of Electrical Tape - Can be Found at 
True Value, Home Depot, Lowe's, and Amazon
7) 1x Audio Jack - Can be Found at RadioShack

You will also need some tools/glue.

1) Scissors or Knife
2) Glue (hot glue works best)
3) Sandpaper or Lighter

Step 3: Start Building

For this step, you are going to take your Bowl and Magnet.  Put some hot glue in the center of the bowl. Then take your magnet and center it in the glue and press firmly until glue dries (your speaker basket).

Step 4:

For this step, you will need the Index Card, Speaker Basket, Electrical Tape, and Wire.  Take the index card and make a cylinder with a diameter just bigger than your magnet.  You also want the cylinder to be long enough so that it is covering the magnet halfway above bottom of bowl when it is level with the bowl's rim.  Then you want to tape the cylinder so that it does not open back up.  Then wrap your wire around the part of cylinder that covers magnet as many times as you could (your coil).  The more wraps, the better and louder your speaker will be.  When you are done wrapping, make sure you protect your coil with tape so that it does not unravel.

Note: Make sure you leave enough wire that is not wrapped so that you have something to attach your audio jack to.

Step 5:

For this step, you will need your Coil and Plate.  Take the coil and glue it to the center of the plate (your diaphragm).

Note: Make sure your coil/index card cylinder is the same measure as the bowl's depth.

Step 6:

For this step, you will need the Diaphragm and SpeakerBasket.  Take the speaker basket and cut a small hole through the side. Then take the wires coming from the coil attached to the diaphragm, and fish them through the hole in the speaker basket.  Then glue the diaphragm's plate to the rim of the speaker basket's bowl.

Step 7: Finishing Touches

For the last few finishing touches, take your speaker and fill the hole in the speaker basket with glue.  After the glue has dried, take a lighter or sandpaper and burn or scrape the enamel coating off the wires.  Then take the bare wires and solder or just wrap electrical tape around the wire coming from the speaker to the audio jack lead. 

Step 8: Testing Your Speaker

To test your speaker, plug the audio jack into music player (iPhone, iPod, mp3, computer, etc.) and listen to your awesome homemade speaker!

Step 9: Tips

1) The more powerful the magnet, the louder your speaker will be.
2) The thinner your wire and the more times you wrap it around the index card will result in a louder speaker.
3) The bigger your plate, the more defined your bass will be (lower pitch sounds - the sounds that make your heart thump).
4) The smaller your plate, the more defined your treble will be (higher pitched sounds - the sound that, in movies, breaks windows when a female screams loud enough).

Step 10: Troubleshooting

If your speaker does not play any sound,
1) make sure your connections are good and not touching each other.
2) make sure you stripped enough enamel coating off wires.
3) make sure you used insulated wire.
4) make sure your device is working.

If your speaker plays sound that is too low,
1) try to get a more powerful magnet.
2) wrap wire more times around index card.
3) buy an amplifier at RadioShack for around $30.
4) make sure that your device's volume level is on the highest level.

If your speaker is vibrating a lot and not playing clear sound try to
1) use a smaller plate.
2) use an EQ (for an iPhone: Settings > Music > EQ > Scroll through list to find Bass Reducer/Treble Increaser).

If there is a lot of distortion try
1) lowering the volume.
2) play around with the EQ (for an iPhone: Settings > Music > EQ > Scroll through list and test out different EQ settings).