Building the Parametric Speaker kits to be used in the Render exhibition.
Half Bridge Driver IC
Pulse Width Modulation Control Circuits
Multichannel possiblities, multiple mics
Realtime audio for installation
Sound in space – Audio split into bass from subs (wash of spatial bass) and use motorised parametric speakers to deliver moving higher pitched sounds e.g. wing vibrations etc – could sound like bees are swarming around the listener – induced psychological effect, primitive flight or fight adrenal response in listener?
Acoustic Ecology of the city.
infrared footage inside the comb
Z7 Sony camera slow motion or Canon 7D slow motion of bees entering and returning, slowed down further using twixtor or similar
Motion Control Time Lapse – time lapse with arduino controlled motion control rig
Multi-camera windows onto the hive
Further Audio notes:
A carbon microphone, formerly used in telephone handsets, is a capsule containing carbon granules pressed between two metal plates. A voltage is applied across the metal plates, causing a small current to flow through the carbon. One of the plates, the diaphragm, vibrates in sympathy with incident sound waves, applying a varying pressure to the carbon. The changing pressure deforms the granules, causing the contact area between each pair of adjacent granules to change, and this causes the electrical resistance of the mass of granules to change. The changes in resistance cause a corresponding change in the voltage across the two plates, and hence in the current flowing through the microphone, producing the electrical signal. Carbon microphones were once commonly used in telephones; they have extremely low-quality sound reproduction and a very limited frequency response range, but are very robust devices.
Unlike other microphone types, the carbon microphone can also be used as a type of amplifier, using a small amount of sound energy to produce a larger amount of electrical energy. Carbon microphones found use as early telephone repeaters, making long distance phone calls possible in the era before vacuum tubes. These repeaters worked by mechanically coupling a magnetic telephone receiver to a carbon microphone: the faint signal from the receiver was transferred to the microphone, with a resulting stronger electrical signal to send down the line. (One illustration of this amplifier effect was the oscillation caused by feedback, resulting in an audible squeal from the old “candlestick” telephone if its earphone was placed near the carbon microphone.)
how carbon microphones work
Instrumentalizing Failure: Edison’s Invention of the Carbon Microphone
Author: Ian Willsa
MO-64 Insect Mic
In 1999, very special contact mic, called “Insect Mic” (MO-64) was introduced. It can pick up sound of ants’ footsteps or heart beat of snail.
Preliminary Data Sheet
MO-64: Super High Sensitivity Contact Microphone
The Sanken MO-64 microphone was originally designed for the purpose of academic
research. The MO-64 has a very special contact point, and through it can detect sounds which are inaudible to the human ear, such as the sound of an ant’s footsteps and the heart beat of a snail.
Due to its high sensitivity, the applications for this product are quite diverse. It can hear the vibration of a building wall, can be used for the detection of termites, for research of old trees and medical usage. Various documentary productions have used the MO-64 for the recording of insect activity.
•MO-64 (floor or table top) and the MO-64B (used with microphone stand)
Transducer: ————————-Moving coil
Output impedance:—————-600 ohms
Output connector: —————-XLR-3-12 Balanced
Dimensions: ————————MO-64: 90mm(diameter) , 50mm(H)
——————————————MO-64B: 40mm(diameter), 100mm(H)