Guidelines for Selection of Windscreens
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Which pop screen or wind screen is right for my microphone?
Before taking up this question, one should first consider the choice of microphone type.
With a SCHOEPS supercardioid, the level of noise in mild to moderate wind will be some 2 to 5 dB higher than with a SCHOEPS cardioid under similar conditions. But the difference in wind noise pickup between pressure transducers and pressure gradient transducers generally (i.e. omnidirectional microphones vs. directional microphones as a class) can be as much as 20 dB. Thus when wind noise is a factor, one should always consider whether an omnidirectional microphone could perhaps be used. Furthermore, it should be considered that a windscreen will affect the low-frequency polar pattern of a directional microphone (see below).
One widely useful choice of capsule would be the switchable-pattern MK 5 (omnidirectional/ cardioid).
In general, when comparing two windscreens which are equally efficient, the smaller one will always have a greater adverse effect on sound quality. If two windscreens are the same size, the one which is more efficient will have the greater adverse influence on sound quality ? altering the microphonefs frequency response and (with directional microphones) the polar pattern as well. Thus it is advisable to select a windscreen that is only as efficient as is really necessary, and perhaps to use a larger windscreen rather than a smaller one that has the required degree of efficiency.@
Establishing some terms:
Pop screens are only for indoor use, to reduce the air currents produced when singers or speakers pronounce consonants such as gph or gth.
Close speech guards are for use in moderate air currents and with microphones on moving boom arms, and/or as heavier-duty pop screens.
Wind screens suppress even more strongly the disturbances due to air motion, making it possible to record outdoors.
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Screens for pressure transducers
- MK 2, MK 2H, MK 2S, MK 3, omnidirectional setting of MK 5 and MK 6-The most suitable wind screens generally are those made of homogeneous, fine open-pore foam. They are also the simplest and least expensive choice.
Effect on sound quality: Limited to a high-frequency rolloff which can be corrected with equalization or by choosing a brighter sounding capsule.
Effect on polar response: None.Practical suggestions: Adequate protection should be available from a light foam windscreen (B 5) for mild wind or a thicker windscreen (W 5) for stronger wind. Further protection would require a basket-type windscreen with fur-like covering. Since wind noise can cause extremely high output levels at low frequencies, the input of the equipment to which the microphone is connected can become overloaded, which may create the false impression that the microphone itself is being overloaded. Thus one might also consider using a low-cut filter (CUT 1 or LC 60).
The following combinations have worked particularly well in practice: Capsule MK 2S or MK 3, foam wind screen W 5 or W 5 D, and Active Low-cut Filter CUT 1 or in-line filters LC 60 or LC 120.Hollow foam windscreens and basket-type windscreens can also be used.
Effect on sound quality: Again the effect is restricted to the high frequencies, but in addition to the rolloff, a slight unevenness of response is introduced. This will depend on the capsule type, the diameter of the basket, the position of the microphone within the basket and the possible use of a fur-like govercoath. The degree of wind noise suppression will depend on the thickness of the foam and the "overcoat."
Effect on polar response: Slight, and limited to the high frequencies.
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Screens for pressure gradient transducers
- such as the cardioid MK 4 or supercardioid MK 41 -For this case we recommend wind screens that have an enclosed volume of air. There are two types:
a) hollow foam windscreens
and
b) basket-type windscreens.
The latter type is often augmented by an optional fur-like covering which increases its effectiveness.Effect on sound quality: There is some reduction of low-frequency response, since the pressure difference between the front and rear sound inlets of the capsule is made smaller by the basket structure. At high frequencies, in addition to a slight rolloff, a certain unevenness of response is introduced. This will depend on the capsule type, the diameter of the basket, the position of the microphone within the basket and the possible use of a fur-like govercoat.h Wind screens with this type of covering (e.g. W 20 R1) are especially effective because no wind turbulence will arise at their surface while any existing turbulence will be reduced.
Effect on polar response: At low frequencies the decreasing pressure gradient component will cause the directional pattern to become more nearly omnidirectional. In extreme cases a supercardioid may take on a cardioid pattern at low frequencies, while a cardioid capsulefs pattern may resemble that of a wide cardioid or an omnidirectional capsule.Practical suggestions: The hollow windscreens B 5 D and W 5 D are suitable for mild to moderate wind conditions. In strong wind, the largest practical basket-type windscreen should be used (e.g. WSR MS) with a fur-like outer covering.
Perhaps an optimal balance of size and effectiveness can be achieved by using the W 20 R1 windscreen and either the Active Low-cut Filter CUT 1 or the in-line filters LC 60 or LC 120.
