The main difference between popscreens and windscreens is the degree of their efficiency. Windscreens are more efficient than popscreens at reducing disturbances due to air motion, and they are generally used outdoors. Popscreens are more frequently found indoors, where they can efficiently reduce a transducer's sensitivity to breath plosives and microphone boom movements without impairing the sound quality.  

Choice of Screen:

A distinction must be made between simple foam windscreens and basket-type or hollow-sphere foam-type windscreens.

For use with pressure (omnidirectional) microphones, both acoustic foam types and hollow-sphere foam windscreens are appropriate. When compared to basket-type windscreens they have a less detrimental effect on sound quality.

Cardioids and other pressure-gradient transducers, on the other hand, are best protected when their sound inlets are kept within an enclosed air chamber. Basket-type and hollow-sphere foam windscreens accomplish this; solid-foam types are less effective. Types with a fur-like covering (such as the W 20 R 1) are especially efficient. This kind of surface does not create any air turbulence and, at the same time, it reduces whatever turbulence may already exist.  

Adverse Effects on Sound Quality:

In general, when comparing two windscreens which are equally efficient, the smaller one will always have a greater influence on the sound. Conversely, if two windscreens have the same size, the more efficient one has the greater adverse influence on sound quality, usually impairing a microphone's frequency response as well as the polar pattern of directional microphones. It is thus advisable to select a windscreen that is no more efficient than necessary, and as large as feasible.

Acoustic foam windscreens generally do no more harm than to cause some roll-off at high frequencies. This can be corrected either through electronic equalization or by choosing a brighter microphone capsule (e.g., MK 3). Hardshell basket windscreens, however, produce irregularities in high-frequency response (depending on the type of capsule) which cannot be easily compensated for and which color the sound noticeably. With pressure-gradient transducers they also reduce low-frequency sensitivity and directivity.

The use of hollow-sphere foam windscreens on pressure-gradient transducers leads to much less roll-off and coloration at high frequencies, but also reduces low-frequency sensitivity and directivity.

Influence of the Microphone Type:

Omnidirectional microphones (pressure transducers) are especially resistant to the effects of wind. Among directional microphones (pressure-gradient transducers) the speech types, with their attenuated low frequencies and stiffer diaphragms, are also somewhat less prone to wind noise.

Since the level of low-frequency energy in wind noise is very high (usually with a large infrasonic component), a mixing console or recorder input can be overloaded, especially if transformer-coupled, making the microphone seem to be more susceptible to audible wind noise than it actually is.

In such cases the active low-frequency CUT filter is particularly helpful.

Suggestions:

An omnidirectional microphone should be used whenever possible, since its inherent sensitivity to wind is about 20 dB-A lower than that of a pressure-gradient transducer. The combination of the MK 3 (or MK 2 S) capsule with the foam windscreen W 5 or W 5 D and the CUT 1 bass filter is highly recommended.

The additional variable low-frequency roll-off of the CUT 1 filter is advantageous here, since the perfect low-frequency reproduction of pressure transducers may lead to strong low-frequency contributions from undesired ambient noise other than wind.

Due to its relative insensitivity in this frequency range, a pressure-gradient capsule would be less likely to pick up such noise at audible levels.

With directional capsules, a combination of the basket windscreen W 20 R 1 and the CUT 1 filter represents the optimum in efficiency-versus-size.