How To Make A Speaker Horn Into A Microphone

A fun electrical project that works well with a lesson on acoustics is how to make a speaker horn into a microphone. It sounds difficult but when you break down how a microphone works, it’s not. A microphone works by taking acoustical pressure waves in through the diaphragm and converting it into electrical voltage waves. With a little work, a diaphragm in a speaker can do this as well.

 Items needed to convert a speaker into a microphone:

•  speaker ( see note below)
• amplifier
• speaker wire
• wire stripper

1. Cut the speaker wire. Make sure you cut it long enough to reach from where the amplifier will be to where you want to put the speaker so it can easily pick up what you wish to record.
2. At each end of the speaker wire, carefully split it at each end of the wire. Now pull the two pieces apart about five inches.
3. Do this for both ends of the wire. You will now have four ends to the speaker wire.
4. Using the wire strippers, strip about a quarter an inch of the coating off of the wire on all the ends. Careful not to break the wire on this part.
5. Connect the top of the wire to the contacts of the speaker. One wire of the top end should connect to the positive contact, while the other wire of the top end should connect to the negative contact. The bottom end of the wire will be free.
6. Now repeat step 5 with the contacts of the microphone connector. Then attach the connector to the amplifier.
7. Test your new microphone is picking up sound. Volume might need to be adjusted. Using the speaker as a microphone will create a unique sound compared to that of a normal microphone.
8. Have fun and enjoy playing with the sound picked up by your creation!

 Note:

• There is no need to use a new speaker. A used speaker, as long as it is functional, will work just fine for this project. Try second hand stores and garage sales.