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ALL YOU NEED TO KNOW
Below you'll find advice about polar patterns, microphone types, applications and tips on mic placement and recording techniques. If there's anything you specifically want to ask (and can't find the answers to below) email us and we'll be more than happy to help!
Different types of microphones have been developed over the years, either to deal with different recording situations or to take advantage of changes or advancements in technology. Here's a quick guide…
Some of the most commonly used microphones are condenser (also known as capacitor) microphones.
Inside the head of the microphone is a capsule, a small circular disc of very thin metal usually covered in a thin layer of gold with an attached electrical wire (usually in the centre but sometimes, as with our ARIA mic, at the edge - known as edge-terminated).
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. This is transmitted through the cable attached to the capsule.
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.
Some condenser microphones employ two capsules to allow the mic to pick up sound from 360° around it. This means polar patterns such as omnidirectional and figure-of-eight can be employed (read more about polar patterns below).
Sontronics condenser mics: ARIA • DM-1B • DM-1S • DM-1T • HELIOS • MERCURY • ORPHEUS • SATURN • STC-1 • STC-10 • STC-2 • STC-2X •
STC-20 • STC-3X • STC-6
Sontronics ORPHEUS condenser mic
with one of its two capsules shown
inside the grille
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 that a dynamic mic's capsule responds more slowly than that of a condenser mic, and therefore it is not as accurate as a condenser microphone at capturing subtle detail, especially in the highest and lowest frequencies. This leads to the results sounding a little
It is, however, less prone to damage than a condenser microphone, it can withstand moisture better and it 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 mics: STC-80 • HALO
Sontronics HALO dynamic 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 more on polar patterns below).
Being dynamic, ribbon microphones have a very specific frequency response, generally producing less low and high frequency output. However, their character makes them excellent 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 experience gradual wear and tear through time, and 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
Sontronics SIGMA ribbon microphone
with the two vertical magnets catching the light and the corrugated ribbon in between
Sontronics DELTA ribbon microphone
in use on guitar amplifier
The polar pattern of a microphone is the description of how a microphone picks up sound in the 360° space around it, and is are usually depicted in a 2D diagram (see below). The most commonly used polar patterns for microphones are omni-directional (omni), cardioid and figure-of-eight…
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…
• ARIA • STC-10 • STC-1 • STC-1S
• STC-20 • STC-2 • STC-3X
• STC-6 • STC-80 • HALO
• DM-1B • DM-1T • DM-1S
• ORPHEUS (plus omni & figure-of-eight) • HELIOS (variable from omni to
figure-of-eight) • MERCURY (variable from omni to figure-of-eight)
• SATURN (five patterns in total)
An omni-directional pattern picks
up sound equally from all directions,
like a large sphere around the head of the microphone.
This pattern is useful for recording groups, ensembles and
choirs, for using overhead on a large instrument such as piano or drumkit
as well as for capturing the natural ambience of a room or performance space.
Mics with omni pattern…
• ORPHEUS (plus cardioid & figure-
• HELIOS (variable from
omni to figure-of-eight)
• MERCURY (variable from omni to figure-of-eight)
• SATURN (five patterns in total)
Another common polar pattern is
figure-of-eight, which picks up an
equal response from the front and the rear of the microphone with complete rejection at the sides.
A single figure-of-eight microphone can give a very intimate reproduction of sung vocals or solo instruments, and also for use in stereo applications where rejection of sound and noise from the off-axis is critical.
A figure-of-eight mic can be used in combination with a cardioid mic for mid-side technique.
Mics with figure-of-eight pattern…
• SIGMA • DELTA • APOLLO (x2)
• ORPHEUS (also omni & cardioid)
• HELIOS & MERCURY (both variable from omni to figure-of-eight)
• SATURN (five patterns in total)
By combining variations of different patterns it is possible to create other kinds of directional polar pattern, such as subcardioid, hypercardioid and supercardioid.
• Hypercardioid, found by combining cardioid with figure-of-eight, offers a good overall rejection and a flatter frequency response, while having a low sensitivity to sounds coming from the rear of the microphone.
• Subcardioid, sitting somewhere between cardioid and omnidirectional, reduces the level of proximity effect (see below) while maintaining excellent off-axis rejection.
Often, when talking about microphone placement, you'll hear the phrase 'proximity effect'. This describes the phenomenon you experience when a cardioid (or 'pressure-gradient') microphone is moved closer to its sound source and its bass response increases.
When recording vocals, a weaker-voiced singer can move closer to the microphone and achieve a richer, more intense sound. It's also a classic technique for voiceover artists to sound deeper and more intimate.
If you're experiencing too much proximity effect but don't want to change your mic positioning, you can take advantage of the mic's low-cut filter (see below), which can be found on most of our condenser microphones.
Singer/songwriter Mark Joseph taking
advantage of proximity effect on his STC-2
PAD & FILTER CONTROLS
As instruments and voices can vary wildly in character as do the methods by which they can be captured, you need to be flexible. In order to make our mics as versatile as possible and to help you get the best possible recording every time, most of our mics feature filter and attenuation or pad controls.
The low-cut filter reduces the output of lower frequencies captured by the microphone. As mentioned above, this is particularly useful when the proximity effect may not be desired or where low-frequency sounds such as vibrations or distant traffic rumble are being picked up. It is also very useful when your sound source exhibits little or now low-frequency output. In this case, the filter can be switched in to add definition to your recording while limited unwanted noise.
The pad switch is used to attenuate (or reduce) the sensitivity of the microphone by a number of decibels (usually -10 or -20dB). This is very useful when recording a loud sound source (for example, a trumpet played directly at the mic) which could overload the sensitive internal electronics and cause unpleasant distortion. In this case, the pad can be switched in to reduce the level of sound being captured by the microphone but allowing it to still pick up and reproduce the characteristics of the instrument.
If your microphone doesn't have an attenuation control, our ST-PAD/PHASE gadget can be used inline with any other microphones. It gives you two levels of -10dB pad as well as a 180° phase inverse feature.
Our Sontronics SATURN features pad and filter controls on the front of the mic body
as well as the polar pattern selector