| Pressure transducers | | | | Dynamic microphones work on the basis on |
| Only the front face of a pressure transducer is | | | | magnetism. As the coil, that is mounted to the |
| exposed to the sound field. The diaphragm responds | | | | diagram moves in and out in relation to the SPL and |
| equally to all sound pressure fluctuations hitting the | | | | cuts through the magnetic field. A current is induced |
| surface, doesn't matter form which direction the | | | | in the coil, and that is a voltage representation of the |
| sound. Pressure transducers have no directional | | | | sound. |
| characteristic, and are Omni directional. | | | | Variable Capacitance Transducer |
| Pressure gradient transducers | | | | There are two plates placed close to each other, |
| These microphones have a figure-8 pickup pattern | | | | there is a potential difference on the plates. As the |
| along the longitudinal axis. They respond to the | | | | SPL hits the diaphragm the plates start to bind in |
| momentary sound pressure difference between two | | | | relation to the sound. As the plates bend it causes |
| points A and B, which are a slight distance apart in | | | | electrons to jump, and you will get the voltage |
| the sound field. | | | | representation of the sound |
| Pick up Patterns | | | | Multi Pick up pattern |
| Omni directional | | | | 1. A microphone with multiple pickup patterns typically |
| An Omni directional microphone, reveres to Omni | | | | uses voltage difference between two condenser |
| because it hears from all direction. Provide the fullest | | | | cardiod capsules. The different voltages on the plate |
| sound from a distance. Omni is good to capture | | | | causes different pick up patterns. Here are the |
| ambience and the room sound. | | | | different voltages on the different plates. |
| Pressure transducer | | | | Omni = + + |
| Bidirectional | | | | Fig 8 = + - |
| Bidirectional microphones only hearse from the front | | | | Cardiod = + - |
| and the back and nothing from the sides. | | | | Cardiod = + + |
| Cardioid | | | | 2. A microphone with ports on their side provides an |
| Hears most of its sounds from the front and only a | | | | alternate way to put the sound from the back and |
| little from the back. | | | | the sound from the front out of phase. And change |
| Transducer type | | | | between Omni and cardiod. |
| Magnetic Induction Transducer | | | | |