SPKR MiK: How to make a microphone from a speaker.

Step 1 Materials and Tools

Materials

• 6.5" dual coil woofer speaker (4ohm). I pulled this one from an Altec Lansing multimedia system that had a blown amplifier.
• 10" drum. Cheap is okay, but you'll want something with lugs that screw into the shell, not springs or T-rods that screw into couplers. I found this one for $2 at a second hand store.
• Two miniature bungee or elastic cords. I got a 4 pack for $2.50
• Crimp on terminal rings. I paid $2.50 for a dozen
• Adjustable hose clamp (the same diameter as the magnet of your speaker). This was about $1.50 at the hardware store.
• Female mounting flange for 3/8" microphone stand and small bolts to mount it. I got this at Parts Express
• 2 sq. ft. of speaker grill cloth. Also at Parts Express
• Thread
• Male XLR 3pin panel mount connector and mounting screws
• Two 1/4" TS (mono) female phone jacks (at least one needs a tab for a normalling connection)
• A six-pole four-throw rotary switch (I scrounged my switch from a 4-way printer "data" switch box), or you can use Mouser part no. 105-SR2921F-34S
• 100 ohm potentiometer, also called a variable resistor
• two knobs (for pot and rotary switch)
• Two DPDT toggle switches (on-on)
• A SPST toggle switch
• Resistors: 100k ohm, two 10k ohm, 10 ohm
• 100nF capacitor
• 1:1 ratio audio isolation transformer (pulled from a second hand 270-054 I got for $1)
• metal container to hold and shield transformer, and mounting hardware
• heat shrink tubing or electrical tape
• connecting wire. 22ga or 24ga is fine.
• short microphone stand (another second hand store find)

Tools

• Small adjustable wrench
• Drill
• Soldering iron and solder
• Wire stripper/crimper
• Scissors
• Sewing needle
• Screwdrivers
• Small hack saw
• Ruler, or other measuring device
• Sharp hobby knife
• Marking pen

Optional

• Rotary tool
• Drum key
• Pliers, tweezers, or other soldering aids
• Adjustable calipers
• Cutting mat
• label maker