This instructable shows you, how to make an easy microphone or pickup using headphones. In theory you can make this from any speaker, but speakers from headpones are better because they have nice sensitive membrane.
Step 1: You'll Need...
Headphones - I used this old Genius headphones (I don't know the type, because there is no label on it)
Holick wires (I don't know how to name it)
Some wire (shielded better, but I don't have one)
1/4 female jack (6,3 mm)