All content © 2010
Omnisonic International Ltd |
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WHAT IS A CONDENSER MICROPHONE?
Some of the most commonly used microphones are condenser or capacitor microphones. Inside the head of the microphone is a capsule, and when sound pressure from an audio source reaches the capsule, the microscopically thin diaphragm on the face of the capsule moves, resulting in changes in electrical value or capacitance.
Condenser microphones are extremely sensitive and therefore able to capture their subjects quickly and accurately. Their wide frequency response enables them to produce very natural recordings that are true to the original sound. For these reasons, condenser microphones are most often used in recording studios and other professional applications where absolute accuracy is critical.
Sontronics condensers: SATURN • ORPHEUS • HELIOS • OMEGA • STC-10 • STC-1 • STC-1S • STC-20 • STC-2 • STC-2X • STC-6
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WHAT IS A DYNAMIC MICROPHONE?
Inside the head of a dynamic microphone is a capsule, but attached to its diaphragm is a tiny coil set within the field of a permanent magnet. When the soundwave reaches the diaphragm it vibrates, moving the coil and creating a varying current in the electro-magnetic field.
The mass of the coil means a dynamic mic's capsule responds more slowly than that of a condenser mic, and so it's not as accurate as a condenser at capturing subtle detail, especially in the highest and lowest frequencies. It is, however, less prone to damage than a condenser microphone, it can withstand moisture and can take more signal before feeding back, and these factors have led to dynamic microphones being used as vocal mics for stage performance and live sound reinforcement.
Sontronics dynamic mic: STC-80
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WHAT IS A RIBBON MICROPHONE?
A ribbon mic is another type of dynamic microphone, but instead of a coil attached to a diaphragm, it features a microscopically thin, corrugated metallic ribbon suspended in a magnetic field. Commonly a ribbon microphone is open to sound at the front and back, giving a figure-of-eight or bi-directional pattern (see below).
Being dynamic, ribbon microphones have a very specific frequency response, generally producing less low and high frequency output. However, their character makes them an excellent partner for acoustic instruments due to their limited ability to pick up ambient frequencies or 'air' delivering a very authentic, 'natural' result. For this reason ribbon microphones are particularly good for miking electric guitar cabinets.
Historically ribbon microphones earned a reputation for being extremely fragile and it was inadvisable to use them with very loud or low sound sources. Their dynamic nature resulted in low sensitivity and, since significant levels of gain were required to reach a reasonable output level, this led to difficulties in achieving a respectable signal-to-noise ratio.
However, our SIGMA, DELTA and APOLLO ribbon microphones solve and avoid these problems through the addition of a 48V preamplified circuit, giving them a significant boost in sensitivity and the ability to reproduce stable and consistent results without the noice problems of the past.
Furthermore, these three microphones, particularly DELTA, have been engineered to withstand every day use in both studio and live sound applications.
It is worth noting, though, that the ribbons inside the mics, like the tyres on a car, do pick up gradual wear and tear through time, and that you should contact us to get your ribbon microphone regularly serviced and checked. You may even need to replace the ribbon at some point during the microphone's lifetime.
Sontronics ribbon mics: DELTA • SIGMA • APOLLO |
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POLAR PATTERNS
A polar pattern is the representation of how a microphone picks up sound in the 360° space around it. The most commonly used polar patterns for microphones are omni-directional (omni), cardioid and figure-of-eight…
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An omni-directional pattern picks
up sound equally from all directions,
which is useful for recording choirs
and groups of musicians, and also for
capturing the natural ambience of a
room or performance space.
Sontronics mics with omni pattern…
• ORPHEUS
(also cardioid & figure-of-eight)
• HELIOS
(variable from omni to figure-of-eight)
• SATURN (five patterns in total)
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A cardioid pattern picks up sound
from the source it is pointed at but
also offers a graduated rejection of sounds from the side and very
little input from the rear.
When shown on a graph, the pickup response resembles a heart shape,
hence 'cardioid'. Cardioid mics are
also referred to as 'pressure-gradient'.
Mics with cardioid pattern…
• STC-10 • STC-1 • STC-1S
• STC_20 • STC-2 • STC-2X
• STC-6 • STC-80 • OMEGA
• ORPHEUS
(also omni and figure-of-eight)
• HELIOS
(variable from omni to figure-of-eight)
• SATURN (five patterns in total)
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Another common polar pattern is
figure-of-eight, which picks up an
equal response from the front and the rear of the micropone but offers
excellent sound rejection from both
sides or 'off-axis'.
Mics with figure-of-eight pattern…
• SIGMA
• DELTA
• APOLLO
• ORPHEUS (also omni & cardioid)
• HELIOS
(variable from omni to figure-of-eight)
• SATURN (five patterns in total) |
By combining cardioid and figure-of-eight patterns it is possible to create other kinds of directional polar pattern, such as subcardioid, hypercardioid and supercardioid. The hypercardioid pattern offers a good overall rejection and a flatter frequency response, while having a low sensitivity to sounds coming from the rear of the microphone.
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WHAT IS THE PROXIMITY EFFECT?
Often, when talking about microphone placement, you'll hear the phrase 'proximity effect'. Basically it describes the phenomenon you experience when a cardioid (or 'pressure-gradient') microphone is moved closer to its sound source and its bass response increases. This can actually be used to your advantage, especially for vocals, as it adds a deeper sound to your voice. If, however, you prefer to avoid the effect, you can use a low-cut filter.
The proximity effect can be used to get great results on Sontronics SATURN, ORPHEUS, STC-6, STC-10, STC-1, STC-2X and STC-2 (pictured), all of which have a low-cut filter switch built in.
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USING LOW-CUT FILTERS & ATTENUATION SWITCHES
As mentioned above, the low-cut filter on a microphone simply reduces the output of the lower frequencies captured. This is particularly useful when the proximity effect is causing a problem, or where low-frequency sounds like traffic noise or stage vibrations are being picked up by the mic. It is also very using when the source being recorded exhibits little or no low-frequency output, where the filter could be employed to add definition to your recording while limiting unwanted noise.
An attenuation switch or pad is used to reduce (or attenuate) the sensitivity of the microphone, especially where a very loud sound source could overload the preamplifier and cause unpleasant distortion. For example, a trumpet played directly at the microphone is very likely to overload the preamp, so a pad could be used to attenuate the level but still allowing the microphone to capture the characteristics of the instrument itself.
In January 2010 Sontronics launched the ST-PAD/PHASE standalone switch that can be used inline with any other microphones. The switch gives two levels of -10dB attenuation as well as a 180° phase inverse feature.
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USING SONTRONICS MICS
Within our range of studio microphones, we have a model to suit most applications, whether you're recording a symphony orchestra in a professional studio or a single saxophone in your front room. Here's a quick guide to what our mics are good for, but click on each one to find out more…
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