Handbook for Sound Engineers

Microphones 577

microphone. However, in a strong gale a small devia-
tion from a perfect flat response may be insignificant
for a >30 dB reduction in wind noise. Wind noise is in
the low-frequency spectrum. For a naked Sennheiser
MKH60, the wind-produced energy is almost entirely
below 800 Hz, rising to a peak of 40 dB at about 45 Hz.

It is the effect of a shield at these lower frequencies that

is most important. Cavity windshields inevitably

produce a slight decrease in low-frequency response in

directional microphones but this is not usually notice-

able. Basket types have very little effect on high

frequency. Fur coverings, while having a major effect in

reducing low-frequency noise, will also attenuate some

high frequency.

Adding the low-frequency attenuation available on

many microphones or mixers (which is usually neces-

sary to prevent infrasonic overload and handling noise

when handholding or booming a microphone) may give

extra wind noise reduction improvements of >10 dB at

the cost of some low-frequency signal loss.

The standard (basket) windshield shows up to 25 dB

wind noise attenuation at 35 Hz while giving almost no

signal attenuation, Fig. 16-163.

The Softie Windshield is a slip-on open cell foam

with an integral fitted fur cover. The Softie reduces

wind noise and protects the microphone. It is the stan-

Figure 16-164. The effectiveness of the windscreen shown in Fig. 16-163. Courtesy B and K Technical Review.

A. Wind noise as a function of frequency with the

wind direction parallel to the capsule.

D. Wind noise as a function of wind speed in the

range 20 Hz to 20 kHz.

C. Wind noise measured with different sizes

of windscreens.

B. Wind noise as a function of frequency with the

wind direction at right angles to the membrane.

Decibels

120 km/h

75 mi/h

30 km/h

19 mi/h

Decibels

120 km/h

75 mi/h

30 km/h

19 mi/h

1/3 Octaves 1/3 Octaves

Decibels

Without

windscreen

With windscreen

dia. = 120 mm (4.7 in)

D = 240 mm (9.5 in)

D = 480 mm (19 in)

km/h km/h

Decibels

(A)

(B)

(C)

(D)

(A) 4131 with standard

protection grid when parallel

to diaphragm

(B) As (A) but with wind at

right angle to diaphragm

(C) As (B) with windscreen

(D) As (A) with windscreen

Figure 16-165. Wind noise reduction options for a
Sennheiser MKH60 microphone under real wind condi-
tions. Courtesy Rycote Microphone Windshields LTD

Windshield

Attenuation–dBSofty Windshield and Windjammer

A

B

C