Speakeroids Open Source Details
Version 1.0

Equipment:
Resonant Objects
De-coned Loudspeakers (drivers)
Amplifiers
Contact Microphones (Piezo buzzers)
Shielded wire for contact microphones
A Mixer, Computer, or some other method of controlling or automating feedback levels
Amplification (commercial or consumer)
Audio Cables

Tools:
Razor Blades
Epoxy
Proboscises (styrofoam spheres, cones, etc.)
Solder and Iron
Screwdrivers and screws

Resonant Objects:
Choose objects that will resonate well in contrast to the other objects chosen, and that have interesting or complex mechanical characteristics.

Suggested objects:
Gongs, slinkies, thunder sheets, cymbals, pans, pots, sheets of metal, snare drums, toms, bass drums, logs, plastic jugs, panes of glass, springs, wind chimes, wires, balloons, water.

Loudspeaker Preparation:
Each resonant object will need to be fitted with an appropriately sized contact microphone and de-coned loudspeaker. The loudspeaker should first be removed from its casing. Cut the cone out, carefully avoiding the two lead wires. This effectively renders the loudspeaker impotent, unable to produce a high volume of sound on its own without attachment to another object. Strengthen the dust cap by applying many thin layers of epoxy in a ventilated room. Attach a proboscis with epoxy to extend the dust cap, if this enables better connection to a resonate object.

Contact Microphones:
Commercial contact microphones can be expensive in large quantities. Piezo buzzers may provide a satisfactory result. A local electronics store should carry many sizes of home door buzzers. These can easily be snapped open and the metal disk inside removed. Solder the contact points on the disk to the two wires in speaker wire.

Speakeroid Construction:
Place or join objects and loudspeaker drivers in such a position that the objects can fully resonate and are not dampened by contact with the loudspeaker drivers. It is important that the speaker driver not carry the weight of heavier objects, and that the speaker driver be of a size and amplification level that it can vibrate the object to produce sound without overheating or sparking (this endangers both the speaker driver and the relevant amplifier).

Beyond that concern, there are a wide range of considerations for speaker/driver integration that will be revealed by empirical investigation with a working system. Loudspeaker drivers can hang or be braced above an object like a drum head, or both can be suspended in the case of an object like a gong. More creative methods for exciting the resonators may also be used, such as attaching a metal wire on one end to a proboscis and on the other end to a snare drum.

Using double-sided tape, attach contact microphones to the objects, experimenting to find expedient positioning.

Feedback System:
All microphones can lead into a system where their signals can be selectively routed back out to any of the speakeroids. A random or other logic-oriented computer system can be designed to provide a variety of sudden and gradual shifts in the independent gain levels for maximum investigation of the system's potentials. The most interesting effects result when two speakeroids feedback upon one another or when a more complex feedback chain is setup, where longer periodicities form as different resonances and mechanical variables battle for supremacy.