Teoría de los micrófonos: Parte 2

Bueno pues, después de semanas de decir que lo haría, ha llegado el momento de seguir con loque faltó del blog sobre los micrófonos. Ya les hablé de los tipos de micrófonos, y la segunda parte es sobre la polaridad. O sea, la manera en que la construcción del micrófono afecta la manera en que el sonido hace que el diafragma se mueva más para uno u otro lado. El resultado es que los micrófonos no agarran igual el sonido que llega de todos lados, y hay distintos patrones de dirección. Como la vez pasada, voy a continuar este blog en inglés para evitarme traducir todos los términos técnicos.

There are four main types of polar patterns: omnidirectional, cardioid, hyper-cardioid and bi-directional or figure 8.

Omnidirectional microphones are the most straightforward, those that pick up sounds coming from all directions at equal amplitudes. With the diaphragm at the centre, this is a picture of its pick-up pattern:

http://en.wikipedia.org/wiki/File:Polar_pattern_omnidirectional.png

Cardioid microphones are so called because their pattern looks a bit like a heart. If I had designed them, I would have called them "baby-ass microphones". These mics have a deaf spot right at the back, and are less susceptible to sound coming from the back and the sides than the front. They are the first kind of directional microphones. They are often used for speech or field recordings, although it is not uncommon to see them in recording studios.

http://en.wikipedia.org/wiki/File:Polar_pattern_cardioid.png

Hyper-cardioid microphones are similar to cardioid, but have a small area of sensitivity at the back, and an even more narrow pattern at the front. Sometimes, highly directional microphones produce a bass boost when placed very close to the sound source. For this reason, some directional microphones have a built-in high-pass filter.

http://en.wikipedia.org/wiki/File:Polar_pattern_hypercardioid.png

Finally, figure 8 microphones are built slightly different and have a pick-up pattern that looks precisely like the number 8. Most ribbon microphones have this pattern.

http://en.wikipedia.org/wiki/File:Polar_pattern_figure_eight.png

These are the main microphone patterns, but are often combined to yield new patterns such as super-cardioid (cardioid + hyper-cardioid), shotgun (figure 8 + hyper-cardioid), etc. In fact, an omnidirectional + figure 8 yields a cardioid pattern. Also, microphones are sometimes built with the option of changing their polar pattern. There are also stereo microphones which are in fact two microphones built together, with the possibility of changing the pattern for each side.

Y bueno, eso es todo lo que sé sobre micrófonos. Cámara.