| Microphone Types | | | | you choose the right pattern for what you'll be |
| Long the role of the professional sound engineer, | | | | using the mic for, or you might capture sounds |
| choosing the appropriate microphone has now | | | | from areas you don't want or lose sound |
| become, with the proliferation of the home studio, | | | | information you need. |
| the task of the amateur and even the beginner. | | | | Omni Pattern |
| This choice should depend upon what you're going | | | | This is the most basic type of mic pattern. It has |
| to be using the mic for, but also on personal | | | | a theoretical 360° pick up response, which |
| preferences. In this article we'll be dealing with the | | | | means that it responds equally to sounds coming |
| two main categories of microphones: dynamic | | | | from all directions. Ideal for group vocals, sound |
| microphones and condenser microphones. | | | | effects, and room ambiances. Omni patterns are |
| | | | pressure sensitive and therefore less sensitive to |
| These mics generally have a more robust design | | | | wind noise than directional (velocity sensitive) mics. |
| due to the fact that they are more often used in | | | | They also give less of an impression of proximity |
| live settings. They are also usually less expensive | | | | than directional mics so they're |
| and resistant to moisture. | | | | Cardioid Pattern |
| Dynamic microphones use a diaphragm which is | | | | This heart-shaped pattern is the most common |
| attached to a coil of wire placed within the | | | | for unidirectional microphones. The name cardioid |
| magnetic field of a permanent magnet. When | | | | come from Greek for heart-shape. This cardioid |
| there's a variation in pressure on the diaphragm it | | | | shape means that its unidirectional and that most |
| will cause the coil to generate a varying electric | | | | of the sound is picked up from the front. This |
| current which then needs amplification. Because | | | | pattern is used for most basic recording situations |
| it's necessary to attach the coil directly to the | | | | or whenever a sound has to be picked up from |
| diaphragm, dynamic mics tend to have thicker | | | | mainly one direction. Because the back of the |
| diaphragms than condenser mics. Because of this, | | | | element rejects sounds it receives, dynamic |
| recordings are less precise as they're less | | | | cardioid mics are often used for live situations. |
| sensitive to high frequencies than condenser mics. | | | | This property helps reduce unwanted spill from |
| Popular models include Shure SM57 and SM58. | | | | other instruments, and therefore reduces the risk |
| Dynamic mics generally don't need any electrical | | | | of feedback. |
| power to operate (as opposed to condenser | | | | Hyper-cardioid |
| mics). They are ideal for all-round high sound | | | | This pattern is similar to cardioid but with greater |
| pressure levels (SPL). | | | | directionality.It has a tighter area of front |
| Condenser or Capacitor Microphones | | | | sensitivity and a tiny lobe of rear sensitivity. |
| Also known as capacitor or electrostatic | | | | Bi-Directional |
| microphones, this type of mic picks up sound | | | | These mics receive sound from both front and |
| through a thin, flexible diaphragm that's placed | | | | back but not from the sides. These mics are ideal |
| next to a metal plate ( as opposed to the rigid | | | | for recording two harmony vocalists, duos, or |
| diaphragm/coil system used by dynamic mics). | | | | face to face interviews with only one mic. |
| Condenser mics can range from inexpensive | | | | Other Considerations |
| Karaoke mics to ultra high level recording mics. | | | | Frequency response |
| Generally, they produce high-quality audio signals | | | | This is a measure of the microphone's sensitivity |
| and are sensitive to distant sounds and high | | | | to different frequencies. It's a characteristic of all |
| frequencies. Because of these reasons they are | | | | mics that some frequencies are exaggerated and |
| often used in studio recording situations. | | | | others attenuated. So the frequency response |
| Because condenser mics are more sophisticated | | | | shows how a particular mic responds to particular |
| and are more difficult to manufacture, high quality | | | | frequencies. |
| condenser mics are rather expensive. Condenser | | | | A chart usually shows a mics's frequency |
| mics are ideal for recording voice, acoustic guitars, | | | | response. The x axis shows frequency in Hertz, |
| pianos, orchestral instruments, percussion, and | | | | the y axis shows response in decibels. A higher |
| sound effects. Some of the most famous models | | | | value means exaggeration and a lower value |
| are the Neumann U47 or the AKG 414. | | | | means attenuation. A completely flat chart |
| Phantom Power | | | | (frequency response) would show that the mic is |
| Condenser mics require a power source, provided | | | | equally sensitive to all frequencies. But in reality a |
| either from microphone inputs as phantom power | | | | totally flat response is impossible and even the |
| or from a small battery. The most common type | | | | best mics have some degree of deviation. Also it |
| of phantom power is +48v DC. This phantom | | | | should be noted that sometimes a mic is |
| power is used to charge the diaphragm and plate. | | | | especially chosen for the specific frequency |
| It also supplies a small amplifier which boosts the | | | | response that it has. For example, a mic with a |
| small current* generated by diaphram | | | | frequency response adapted to the human voice |
| movements. Phantom power supplies are often | | | | would be a good choice for recording in an |
| built into mixing desks, microphone preamplifiers | | | | environment with low frequency background |
| and similar equipment. | | | | noise. |
| Ribbon Microphones | | | | Self Noise |
| Ribbon mics are a type of dynamic microphone. | | | | This measurement represents the lowest point of |
| They use a very thin metal ribbon that's | | | | a mic's dynamic range. This is important if you |
| suspended between the poles of a powerful | | | | want to record very soft sounds. Basically, the |
| magnet. Sound waves cause this ribbon to move | | | | lower the number is, the better. |
| and create an induced current. Voltage output of | | | | Maximum SPL (Sound Pressure Level) |
| older ribbon mics is much lower than dynamic | | | | This is the maximum level a mic can accept. Here, |
| mics so a transformer is used to increase voltage | | | | the higher the number, the better. But one should |
| output and to increase output impedance. Modern | | | | note that mics with very high SPLs have higher |
| ribbon mics avoid this problem by using improved | | | | self noise. |
| magnets and more efficient transformers. Ribbon | | | | Sensitivity |
| mics are usually bi-directional (see next page on | | | | Indicates how well the mic converts sound |
| pick-up patterns). Classic models include the RCA | | | | pressure into output voltage. The higher the |
| 44 and 77 as well as Royer mics. | | | | number, the higher the sensitivity. A highly |
| Pick-up/Polar Patterns | | | | sensitive mics produces more output and will |
| A pick-up (or Polar) pattern, also referred to as | | | | therefore need less amplification after. It should |
| the mic's directionality, indicates to the area(s) | | | | be noted, however, that a higher sensitivity rating |
| from which a mic picks up sound. It shows how | | | | does not necessarily make one mic better than |
| sensitive it is to sounds coming in from different | | | | another. |
| angles about its central axis. It's important that | | | | |