Project:Young Hackspace/YH-3
Links:
Physics of Sound Demos
These are all just proposals. Have yet to try them. Good topics: Periodic motion, the relationship between motion and sound, the frequency spectrum, resonance, harmony, etc.
Wine Glasses: Pitch
Everybody knows this one. But: we have equipment to visualise the frequencies!
- Ken: Wine glasses tuned to different notes with a microphone and osciloscope to show the waveform
Wave Machine: Propagation
Nice, simple. Maybe a bit brittle; but invites playful interaction, which is perfect.
- Paul: http://www.nationalstemcentre.org.uk/elibrary/resource/2096/wave-machine
- "adhesive tape, jelly babies [really any kind of weight] and wooden skewers"
Slinky: Propagation
(artag put one in martind's box.)
- Lay it on a table, waggle the end, watch the wave perturbation propagate.
Glob Monster: Resonance
From Anthony.
- Take the amp in the space, lay it on its back and cover the speaker cone with cling film.
- Mix up some non-Newtonian fluid (corn starch & water) and throw a decent sized glob of it onto the cling film protected speaker.
- Throw various audio signals through the speaker and watch the glob monster dance!
- DIY cymatics!
Metal Tubes: Resonance
Demonstrating acoustic/harmonic resonance with metal tubes.
- We have various hollow metal tubes in the space, of different materials and sizes. Balance one at its centre of mass and strike it with a hard material (screw, hammer, ...) and you'll hear a short high-frequency attack, followed by a sustained lower-frequency resonating hum.
- The frequency of that hum, and the general sound, is dependent on the physical properties of the material; but also on the location of the point where you hold the tube.
- Hold it (hang it vertically) at different positions to get different sounds (we could mark them with tape to indicate "notes".)
- He mentions they even found a tube that had stuffing material rammed into either side, but at varying depths. The result was that the centre of mass of this tube was not the physical centre of the tube, so holding it at the centre of mass resulted in interference of two resonating frequencies, i.e. waves of modulated sound.
Billy and a couple of other "old hippies" (his words) spent an evening striking tubes and playing the bucket bass...
We may have enough tubes to let every kid play with one, provided we can find a way to hold/hang it for them.
Ruben's Tube: ??
Fire! What could go wrong.
- http://en.wikipedia.org/wiki/Rubens'_tube
- SamLR said he might build one
Resonating Spring
There's an excellent piece at the British Art Show at the Hayward Gallery atm, "A Grammar for Listening," where Luke Fowler and a few sound artists filmed sound environments. In one they attached one side of a metal spring to a stand, and subjected it to vibrations (audio oscillators?) of changing frequencies which resulted in amazing organic flows of periodic/chaotic movements.
Plasma Speaker/Flame Amplifier: Fire!
Cool demo, but probably too much work to build.
- Billy: http://www.swtpc.com/mholley/PopularElectronics/May1968/Flame_Amplification.htm
- Randomskk: plasma speaker http://www.youtube.com/watch?v=cEeWtBAE5LY
Directional Sound
Not quite sure how to build this.
- Ken: "How about one of those "sound wave" guns that allows you to fire a pulse of air across a room and put a candle out?"
Sound Generators
Misc ideas for sound generating setups, these things won't necessarily teach you anything but they're fun to play with.
- Ken: Photon phone, make a musical note by tapping a small filament lighbulb from which the light output has been focussed onto a phototransistor and suitable audio amplifier. Old style reflector bike lamps were good for this.
- Ken: Arduino theremin or note generator / bender controlled from 2 axis joystick
- Ken: Musical drawing - use soft graphite pencil on paper to make carbon resistive traces of different shapes and resistances. Trace the drawing with a metal probe to get different sounds from an oscillator - use anlog inputs of Arduino
