Transcript
MICROPHONES POLAR PATTERNS
Every microphone has a property known as directionality. This describes the microphone’s sensitivity to sound from various directions. Some microphones pick up sound equally from all directions, others pick up sound only from one direction or a particular combination of directions. The types of directionality are divided into three main categories. 0º
CARDIOID (HEART SHAPED)
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The most common unidirectional (Single Direction) microphone is a cardioid microphone, so named because the sensitivity pattern is heart-shaped. A hyper-cardioid microphone is similar but with a tighter area of front sensitivity and a smaller area of rear sensitivity. A super-cardioid microphone is similar to a hyper-cardioid, except there is more front pickup and less rear pickup. These three patterns are commonly used as vocal or speech microphones, since they are good at rejecting sounds from other directions.
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OMNIDIRECTIONAL (CAPTURES SOUND FROM ALL SIDES) An omnidirectional (or nondirectional) microphone’s response is generally considered to be a perfect sphere in three dimensions. In the real world, this is not the case. As with directional microphones, the polar pattern for an “omnidirectional” microphone is a function of frequency. The body of the microphone is not infinitely small and, as a consequence, it tends to get in its own way with respect to sounds arriving from the rear, causing a slight flattening of the polar response. This flattening increases as the diameter of the microphone (assuming it’s cylindrical) reaches the wavelength of the frequency in question. Therefore, the smallest diameter microphone gives the best omnidirectional characteristics at high frequencies.
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BI-DIRECTIONAL (FIGURE OF 8)
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A bidirectional microphone is a microphone that picks up sound from the front and back while denying sound from the sides. The term “bidirectional” refers to the directions from which these mics process sound. Sound waves are drawn and captured in the center, allowing for exceptional range in a variety of applications
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!LOOK UP THE APPLICATION OF SUPER AND HYPER CARDIOID PATTERNS TO SEE HOW THEY DIFFER FROM THE REGULAR CARDIOID PATTERN. !BECOME FAMILIAR WITH THE POLAR PATTERNS OF THE MICS YOU HAVE AVAILABLE FOR RECORDING
MICROPHONES POLAR PATTERNS
OMNI DIRECTIONAL
CHARACTERISTIC
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POLAR RESPONSE PATTERN
SUOER CARDIOID
CARDIOID 0º
HYPER CARDIOID
BI DIRECTIONAL
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COVERAGE ANGLE
360º
131º
115º
105º
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ANGLE OF MAXIMUM REJECTION
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126º
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REAR REJECTION (RELATIVE TO FRONT)
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AMBIENT SOUND SENSITIVITY (RELATIVE TO OMNI)
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33%
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DISTANCE FACTOR (RELATIVE TO OMNI)
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1.7
1.9
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MICROPHONE POLAR PATTERNS COMPARED !THE INSTRUCTION MANUALS FOR INDIVIDUAL MICS ARE FREELY AVAILABLE ONLINE AND WILL PROVIDE ACURATE POLAR PATTERN INFO.
!THINK ABOUT HOW YOU WOULD RECORD A LIVE BAND WITH MULTIPLE MICS AND UTILISE THE MAXIUM ANGLE OF REJECTION TO AVOID BLEED.
