IEC 60268-4:2014

FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 General conditions
5 Particular conditions
6 Type description (acoustical behaviour)
7 Terminals and controls
8 Reference point and axis
9 Rated power supply
10 Electrical impedance
11 Sensitivity
12 Response
13 Directional characteristics
14 Amplitude non-linearity
15 Limiting characteristics
16 Balance
17 Equivalent sound pressure level due to inherent noise
18 Ambient conditions
19 External influences
20 Electromagnetic compatibility (EMC)
21 Physical characteristics
22 Classification of the characteristics to be specified
Annex A (normative) - Additional characteristics
Annex B (informative) - Sound insulation device
Annex C (informative) - Simplified procedure for 'pop'
        measurements
Annex D (informative) - Recommendations for professional
        digital microphones
Bibliography

IEC 60268-4:2014 specifies methods of measurement for the electrical impedance, sensitivity, directional response pattern, dynamic range and external influences of sound system microphones, and also details the characteristics to be specified by the manufacturer. This fifth edition cancels and replaces the fourth edition published in 2010, and constitutes a technical revision. It includes the following changes:
- clarification of Table 5 of classification of characteristics;
- clarification of graphical representation;
- clarification of environmental influences;
- rewritten clause for EMC;
- tolerances and more specific values for noise measurements;
- inclusion of near-field response for sound source-to-microphone distances of the order of 30 cm.