BS EN 60268-4:2010
$198.66
Sound system equipment – Microphones
| Published By | Publication Date | Number of Pages |
| BSI | 2010 | 54 |
This part of IEC 60268 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.
It applies to sound system microphones for all applications for speech and music. It does not apply to measurement microphones, but it does apply to each audio channel of microphones having more than one channel, for example for stereo or similar use. It is also applicable to flush-mounted microphones and to the analogue characteristics of microphones with digital audio output.
For the purposes of this International Standard, a microphone includes all such devices as transformers, pre-amplifiers, or other elements that form an integral part of the microphone, up to the output terminals specified by the manufacturer.
NOTE The characteristics specified in this standard do not completely describe the subjective response of the microphone. Further work is necessary to find new definitions and measurement procedures for a later replacement by objective characteristics of at least some of the subjective descriptions used to describe microphone performance.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 7 | CONTENTS |
| 11 | 1 Scope 2 Normative references |
| 12 | 3 General conditions 3.1 General 3.2 Measurement conditions |
| 14 | 4 Particular conditions 4.1 Pre-conditioning 4.2 Sound source 4.3 Measurement of sound pressure 4.4 Voltage measuring system 4.5 Acoustical environment |
| 17 | 4.6 Methods of measuring frequency response Tables Table 1 – Reverberation time of the empty room |
| 18 | 4.7 Overall accuracy 4.8 Graphical presentation of results |
| 19 | 5 Type description (acoustical behaviour) 5.1 Principle of the transducer 5.2 Type of microphone 5.3 Type of directional response characteristics 6 Terminals and controls 6.1 Marking 6.2 Connectors and electrical interface values 7 Reference point and axis 7.1 Reference point 7.2 Reference axis |
| 20 | 8 Rated power supply 8.1 Characteristic to be specified 8.2 Method of measurement 9 Electrical impedance 9.1 Internal impedance |
| 21 | 9.2 Rated impedance 9.3 Minimum permitted load impedance 10 Sensitivity 10.1 General |
| 22 | 10.2 Sensitivities with respect to acoustical environment |
| 24 | 10.3 Sensitivities with respect to nature of signal |
| 25 | 11 Response 11.1 Frequency response Table 2 – Speech power weighting factor at octave-band centre frequencies |
| 26 | 11.2 Effective frequency range 12 Directional characteristics 12.1 Directional pattern |
| 28 | 12.2 Directivity index 12.3 Front-to-rear sensitivity index (0° – 180°) 12.4 Noise-cancelling index |
| 29 | 12.5 Special characteristics for stereo microphones |
| 30 | 13 Amplitude non-linearity 13.1 General 13.2 Total harmonic distortion |
| 31 | 13.3 Harmonic distortion of the nth order (n = 2, 3,…) |
| 32 | 13.4 Difference frequency distortion of second order 14 Limiting characteristics 14.1 Rated maximum permissible peak sound pressure |
| 33 | 14.2 Overload sound pressure 15 Balance 15.1 Balance of the microphone output 15.2 Balance under working conditions Figures Figure 1 – Balance of the output |
| 34 | 16 Equivalent sound pressure level due to inherent noise 16.1 Characteristic to be specified 16.2 Method of measurement Figure 2 – Balance under working conditions |
| 35 | 17 Ambient conditions 17.1 General 17.2 Pressure range 17.3 Temperature range 17.4 Relative humidity range 18 External influences 18.1 General |
| 36 | 18.2 Equivalent sound pressure due to external magnetic fields 18.3 Equivalent sound pressure due to mechanical vibration |
| 37 | 18.4 Equivalent sound pressure due to wind |
| 38 | Figure 3 – Measurement set-up for wind influence |
| 39 | Figure 4 – Wind generators, type 1 (Figure 4a) and type 2 (Figure 4b)) |
| 40 | 18.5 Transient equivalent sound pressure due to “pop” effect |
| 41 | Figure 5 – Electrical and mechanical set-up for the measuring of the “pop” effect |
| 42 | 18.6 Equivalent sound pressure due to electromagnetic interference Table 3 – Reference signal and characteristics |
| 43 | 18.7 Electrostatic discharge 19 Magnetic stray field 19.1 Characteristic to be specified 19.2 Method of measurement 20 Physical characteristics 20.1 Dimensions 20.2 Weight 20.3 Cables and connectors 21 Classification of the characteristics to be specified 21.1 General |
| 45 | Table 4 – Classification of characteristics |
| 46 | Annex A (normative) Sound insulation device Figure A.1 – Sound insulation device |
| 47 | Annex B (informative) Simplified procedure for “pop” measurements |
| 48 | Figure B.1 – Measurement set-up |
| 49 | Figure B.2 – Test fixture for the sound field sensitivity |
| 50 | Annex C (informative) Supplement for digital microphones Table C.1 – Classification of the characteristics to be specified |
| 51 | Table C.2 – Additional digital characteristics to be specified |
| 52 | Bibliography |
