The speaker in an old telephone makes a great lo-fi mic. Just wire a 1/4 inch jack straight up to the speaker and enlarge the telephone jack hole to mount it. A small piece of towel helps to muffle some of the air noise.
You can hear an audio sample on our blog entry. Made by recompas and friends.
Tools and supplies needed:
-old phone headset
- 1/4" audio jack
-about 20" of hook-up wire
-solder / soldering iron
-small piece of towel
Step 1: Unscrew the Speaker and Microphone Caps and Remove Innards
The covers simply unscrew. The only part you'll be keeping from the insides is the speaker. Get rid of everything else, including the telephone jack.
Step 2: Drill Out Telephone Jack Hole to Make Room for 1/4" Audio Jack.
Enlarge the existing telephone jack hole with a 5/16" drill.
Step 3: Solder Wires to and Install 1/4" Audio Jack
First solder wires to the audio jack, then install in the newly enlarged hole. Cut the wires to be long enough so you can easily attach them to the speaker (next step) after the audio jack is installed. The audio jack won't fit through the body of the phone, so you need to install the jack before screwing the wires to the speaker.
Step 4: Screw Wires to Speaker
Some phones will have a resistor across the speaker. Just leave that there.
Step 5: Screw the Caps Back on With a Little Piece of Towel on the Speaker
To help reduce some air noise, put a little piece of towel underneath the cap that goes over the speaker (the new lo-fi mic). Screw both caps back on and you're done.
Again, an audio sample on our blog entry.