IEC 60268-4:2010
(Main)Sound system equipment - Part 4: Microphones
Sound system equipment - Part 4: Microphones
IEC 60268-4:2010 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 fourth edition cancels and replaces the third edition published in 2004, and constitutes a technical revision. The main changes with respect to the previous edition are the following:
- correction of noise measurement,
- added annex for digital microphones,
- added requirement for tolerances in data to be specified.
This bilingual version (2010-09) replaces the English version.
Equipements pour systèmes électroacoustiques - Partie 4: Microphones
La CEI 60268-4:2010 spécifie les méthodes de mesure portant sur l'impédance électrique, l'efficacité, le diagramme de directivité, la dynamique, et les perturbations extérieures des microphones pour les systèmes électroacoustiques, et détaille également les caractéristiques à spécifier par le constructeur. Cette quatrième édition annule et remplace la troisième édition parue en 2004 et constitue une révision technique. Les principales modifications par rapport à l'édition précédente sont les suivantes:
- correction concernant la mesure de bruit;
- adjonction d'une Annexe relative aux microphones numériques;
- adjonction d'une exigence concernant les tolérances des données à spécifier.
Cette version bilingue (2010-09) remplace la version monolingue anglaise. La version française de cette norme n'a pas été soumise au vote.
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IEC 60268-4
®
Edition 4.0 2010-06
INTERNATIONAL
STANDARD
Sound system equipment –
Part 4: Microphones
IEC 60268-4:2010(E)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2010 IEC, Geneva, Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
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International Standards for all electrical, electronic and related technologies.
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IEC 60268-4
®
Edition 4.0 2010-06
INTERNATIONAL
STANDARD
Sound system equipment –
Part 4: Microphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
X
ICS 33.160.50 ISBN 978-2-88910-994-4
® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – 60268-4 © IEC:2010(E)
CONTENTS
FOREWORD.6
1 Scope.8
2 Normative references.8
3 General conditions.9
3.1 General .9
3.2 Measurement conditions .9
3.2.1 General .9
3.2.2 Rated conditions .10
4 Particular conditions .11
4.1 Pre-conditioning .11
4.2 Sound source .11
4.3 Measurement of sound pressure.11
4.4 Voltage measuring system .11
4.5 Acoustical environment.11
4.5.1 General .11
4.5.2 Free-field conditions .11
4.5.3 Diffuse field conditions.13
4.5.4 Microphone coupled to a sound source by means of a small cavity
coupler .14
4.6 Methods of measuring frequency response .14
4.6.1 Point-by-point and continuous sweep frequency methods .14
4.6.2 Calibration methods .15
4.7 Overall accuracy.15
4.8 Graphical presentation of results.15
5 Type description (acoustical behaviour).16
5.1 Principle of the transducer .16
5.2 Type of microphone .16
5.3 Type of directional response characteristics.16
6 Terminals and controls.16
6.1 Marking .16
6.2 Connectors and electrical interface values .16
7 Reference point and axis .16
7.1 Reference point .16
7.2 Reference axis .16
8 Rated power supply .17
8.1 Characteristic to be specified.17
8.2 Method of measurement .17
9 Electrical impedance.17
9.1 Internal impedance .17
9.1.1 Characteristic to be specified .17
9.1.2 Methods of measurement.17
9.2 Rated impedance.18
9.3 Minimum permitted load impedance .18
10 Sensitivity.18
10.1 General .18
10.2 Sensitivities with respect to acoustical environment.19
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60268-4 © IEC:2010(E) – 3 –
10.2.1 Free-field sensitivity.19
10.2.2 Diffuse-field sensitivity .19
10.2.3 Close-talking sensitivity.20
10.2.4 Pressure sensitivity.21
10.3 Sensitivities with respect to nature of signal .21
10.3.1 Rated sensitivity .21
10.3.2 Characteristic sensitivity for speech .21
11 Response .22
11.1 Frequency response .22
11.1.1 Characteristic to be specified .22
11.1.2 Method of measurement .23
11.2 Effective frequency range .23
11.2.1 Characteristic to be specified .23
11.2.2 Method of measurement .23
12 Directional characteristics .23
12.1 Directional pattern .23
12.1.1 Characteristic to be specified .23
12.1.2 Methods of measurement.23
12.2 Directivity index .25
12.2.1 Characteristic to be specified .25
12.2.2 Method of measurement .25
12.3 Front-to-rear sensitivity index (0° – 180°) .25
12.3.1 Characteristic to be specified .25
12.3.2 Method of measurement .25
12.4 Noise-cancelling index .25
12.4.1 Characteristic to be specified .25
12.4.2 Method of measurement .26
12.5 Special characteristics for stereo microphones.26
12.5.1 General .26
12.5.2 Included angle of an XY (left-right) microphone .26
12.5.3 Acceptance angle .26
12.5.4 Threshold angle.27
13 Amplitude non-linearity .27
13.1 General .27
13.2 Total harmonic distortion .27
13.2.1 Characteristics to be specified .27
13.2.2 Method of measurement .27
th
13.3 Harmonic distortion of the n order (n = 2, 3,.) .28
13.3.1 Characteristic to be specified .28
13.3.2 Method of measurement .28
13.4 Difference frequency distortion of second order.29
13.4.1 Characteristic to be specified .29
13.4.2 Method of measurement .29
14 Limiting characteristics .29
14.1 Rated maximum permissible peak sound pressure.29
14.2 Overload sound pressure.30
14.2.1 Characteristic to be specified .30
14.2.2 Method of measurement .30
15 Balance .30
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– 4 – 60268-4 © IEC:2010(E)
15.1 Balance of the microphone output.30
15.2 Balance under working conditions .30
16 Equivalent sound pressure level due to inherent noise.31
16.1 Characteristic to be specified.31
16.2 Method of measurement .31
17 Ambient conditions .32
17.1 General .32
17.2 Pressure range.32
17.3 Temperature range .32
17.4 Relative humidity range .32
18 External influences .32
18.1 General .32
18.1.1 Specification and measuring methods .32
18.1.2 Other external interferences.32
18.2 Equivalent sound pressure due to external magnetic fields.33
18.2.1 Characteristic to be specified .33
18.2.2 Method of measurement .33
18.3 Equivalent sound pressure due to mechanical vibration.33
18.3.1 Characteristic to be specified .33
18.3.2 Method of measurement .34
18.4 Equivalent sound pressure due to wind .34
18.4.1 Characteristic to be specified .34
18.4.2 Method of measurement .34
18.5 Transient equivalent sound pressure due to "pop" effect .37
18.5.1 Characteristic to be specified .37
18.5.2 Method of measurement .38
18.6 Equivalent sound pressure due to electromagnetic interference.39
18.6.1 General .39
18.6.2 Characteristic to be specified .39
18.6.3 Method of measurement .39
18.7 Electrostatic discharge.40
19 Magnetic stray field.40
19.1 Characteristic to be specified.40
19.2 Method of measurement .40
20 Physical characteristics.40
20.1 Dimensions .40
20.2 Weight.40
20.3 Cables and connectors .40
21 Classification of the characteristics to be specified.40
21.1 General .40
Annex A (normative) Sound insulation device .43
Annex B (informative) Simplified procedure for “pop” measurements .44
Annex C (informative) Supplement for digital microphones .47
Bibliography .49
Figure 1 – Balance of the output.30
Figure 2 – Balance under working conditions .31
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60268-4 © IEC:2010(E) – 5 –
Figure 3 – Measurement set-up for wind influence .35
Figure 4 – Wind generators, type 1 (Figure 4a) and type 2 (Figure 4b)).36
Figure 5 – Electrical and mechanical set-up for the measuring of the "pop" effect .38
Figure A.1 – Sound insulation device.43
Figure B.1 – Measurement set-up.45
Figure B.2 – Test fixture for the sound field sensitivity .46
Table 1 – Reverberation time of the empty room.14
Table 2 – Speech power weighting factor at octave-band centre frequencies .22
Table 3 – Reference signal and characteristics.39
Table 4 – Classification of characteristics .42
Table C.1 – Classification of the characteristics to be specified .47
Table C.2 – Additional digital characteristics to be specified .48
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– 6 – 60268-4 © IEC:2010(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SOUND SYSTEM EQUIPMENT –
Part 4: Microphones
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60268-4 has been prepared by IEC technical committee 100: Audio,
video and multimedia systems and equipment.
This fourth edition cancels and replaces the third edition published in 2004, and constitutes a
technical revision.
The main changes with respect to the previous edition are the following:
– correction of noise measurement,
– added annex for digital microphones,
– added requirement for tolerances in data to be specified.
---------------------- Page: 8 ----------------------
60268-4 © IEC:2010(E) – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
100/1678/FDIS 100/1707/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60268 series, under the general title “Sound system equipment”,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual edition of this document may be issued at a later date.
---------------------- Page: 9 ----------------------
– 8 – 60268-4 © IEC:2010(E)
SOUND SYSTEM EQUIPMENT –
Part 4: Microphones
1 Scope
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.
2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
IEC 60065:2001, Audio, video and similar electronic apparatus – Safety requirements
Amendment 1 (2005)
IEC 60268-1:1985, Sound system equipment – Part 1: General
Amendment 1 (1988)
Amendment 2 (1988)
IEC 60268-2:1987, Sound system equipment – Part 2: Explanation of general terms and
calculation methods
Amendment 1 (1991)
IEC 60268-3:2000, Sound system equipment – Part 3: Amplifiers
IEC 60268-5:2003, Sound system equipment – Part 5: Loudspeakers
Amendment 1 (2007)
IEC 60268-11:1987, Sound system equipment – Part 11: Application of connectors for the
interconnection of sound system components
Amendment 1 (1989)
Amendment 2 (1991)
---------------------- Page: 10 ----------------------
60268-4 © IEC:2010(E) – 9 –
IEC 60268-12:1987, Sound system equipment – Part 12: Application of connectors for
broadcast and similar use
Amendment 1 (1991)
Amendment 2 (1994)
IEC 61000-4-2:1995, Electromagnetic compatibility (EMC) – Part 4-2: Testing and measure-
ment techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
Amendment 1 (2007)
IEC 61265:1995, Electroacoustics – Instruments for measurement of aircraft noise – Perform-
ance requirements for systems to measure one-third-octave-band sound pressure levels in
noise certification of transport-category aeroplanes
IEC 61938:1996, Audio, video and audiovisual systems – Interconnections and matching
values – Preferred matching values of analogue signals
ISO 354:2003, Acoustics – Measurement of sound absorption in a reverberation room
ITU-T Recommendation P.51:1996, Artificial mouth
3 General conditions
3.1 General
Special reference is made to IEC 60268-1, concerning:
• units and system of measurement;
• frequencies of measurement;
• quantities to be specified and their accuracy (see also 4.7);
• marking (see also 6.1);
• ambient conditions;
• filters, networks and measuring instruments for noise specification and measurement;
• individual specific
...
IEC 60268-4
®
Edition 4.0 2010-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 4: Microphones
Équipements pour systèmes électroacoustiques –
Partie 4: Microphones
IEC 60268-4:2010
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2010 IEC, Geneva, Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or
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About the IEC
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International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
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---------------------- Page: 2 ----------------------
IEC 60268-4
®
Edition 4.0 2010-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 4: Microphones
Équipements pour systèmes électroacoustiques –
Partie 4: Microphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
X
CODE PRIX
ICS 33.160.50 ISBN 978-2-88912-156-4
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – 60268-4 © IEC:2010
CONTENTS
FOREWORD.6
1 Scope.8
2 Normative references.8
3 General conditions.9
3.1 General .9
3.2 Measurement conditions .9
3.2.1 General .9
3.2.2 Rated conditions .10
4 Particular conditions .11
4.1 Pre-conditioning .11
4.2 Sound source .11
4.3 Measurement of sound pressure.11
4.4 Voltage measuring system .11
4.5 Acoustical environment.11
4.5.1 General .11
4.5.2 Free-field conditions .11
4.5.3 Diffuse field conditions.13
4.5.4 Microphone coupled to a sound source by means of a small cavity
coupler .14
4.6 Methods of measuring frequency response .14
4.6.1 Point-by-point and continuous sweep frequency methods .14
4.6.2 Calibration methods .15
4.7 Overall accuracy.15
4.8 Graphical presentation of results.15
5 Type description (acoustical behaviour).16
5.1 Principle of the transducer .16
5.2 Type of microphone .16
5.3 Type of directional response characteristics.16
6 Terminals and controls.16
6.1 Marking .16
6.2 Connectors and electrical interface values .16
7 Reference point and axis .16
7.1 Reference point .16
7.2 Reference axis .16
8 Rated power supply .17
8.1 Characteristic to be specified.17
8.2 Method of measurement .17
9 Electrical impedance.17
9.1 Internal impedance .17
9.1.1 Characteristic to be specified .17
9.1.2 Methods of measurement.17
9.2 Rated impedance.18
9.3 Minimum permitted load impedance .18
10 Sensitivity.18
10.1 General .18
10.2 Sensitivities with respect to acoustical environment.19
---------------------- Page: 4 ----------------------
60268-4 © IEC:2010 – 3 –
10.2.1 Free-field sensitivity.19
10.2.2 Diffuse-field sensitivity .19
10.2.3 Close-talking sensitivity.20
10.2.4 Pressure sensitivity.21
10.3 Sensitivities with respect to nature of signal .21
10.3.1 Rated sensitivity .21
10.3.2 Characteristic sensitivity for speech .21
11 Response .22
11.1 Frequency response .22
11.1.1 Characteristic to be specified .22
11.1.2 Method of measurement .23
11.2 Effective frequency range .23
11.2.1 Characteristic to be specified .23
11.2.2 Method of measurement .23
12 Directional characteristics .23
12.1 Directional pattern .23
12.1.1 Characteristic to be specified .23
12.1.2 Methods of measurement.23
12.2 Directivity index .25
12.2.1 Characteristic to be specified .25
12.2.2 Method of measurement .25
12.3 Front-to-rear sensitivity index (0° – 180°) .25
12.3.1 Characteristic to be specified .25
12.3.2 Method of measurement .25
12.4 Noise-cancelling index .25
12.4.1 Characteristic to be specified .25
12.4.2 Method of measurement .26
12.5 Special characteristics for stereo microphones.26
12.5.1 General .26
12.5.2 Included angle of an XY (left-right) microphone .26
12.5.3 Acceptance angle .26
12.5.4 Threshold angle.27
13 Amplitude non-linearity .27
13.1 General .27
13.2 Total harmonic distortion .27
13.2.1 Characteristics to be specified .27
13.2.2 Method of measurement .27
th
13.3 Harmonic distortion of the n order (n = 2, 3,.) .28
13.3.1 Characteristic to be specified .28
13.3.2 Method of measurement .28
13.4 Difference frequency distortion of second order.29
13.4.1 Characteristic to be specified .29
13.4.2 Method of measurement .29
14 Limiting characteristics .29
14.1 Rated maximum permissible peak sound pressure.29
14.2 Overload sound pressure.30
14.2.1 Characteristic to be specified .30
14.2.2 Method of measurement .30
15 Balance .30
---------------------- Page: 5 ----------------------
– 4 – 60268-4 © IEC:2010
15.1 Balance of the microphone output.30
15.2 Balance under working conditions .30
16 Equivalent sound pressure level due to inherent noise.31
16.1 Characteristic to be specified.31
16.2 Method of measurement .31
17 Ambient conditions .32
17.1 General .32
17.2 Pressure range.32
17.3 Temperature range .32
17.4 Relative humidity range .32
18 External influences .32
18.1 General .32
18.1.1 Specification and measuring methods .32
18.1.2 Other external interferences.32
18.2 Equivalent sound pressure due to external magnetic fields.33
18.2.1 Characteristic to be specified .33
18.2.2 Method of measurement .33
18.3 Equivalent sound pressure due to mechanical vibration.33
18.3.1 Characteristic to be specified .33
18.3.2 Method of measurement .34
18.4 Equivalent sound pressure due to wind .34
18.4.1 Characteristic to be specified .34
18.4.2 Method of measurement .34
18.5 Transient equivalent sound pressure due to "pop" effect .37
18.5.1 Characteristic to be specified .37
18.5.2 Method of measurement .38
18.6 Equivalent sound pressure due to electromagnetic interference.39
18.6.1 General .39
18.6.2 Characteristic to be specified .39
18.6.3 Method of measurement .39
18.7 Electrostatic discharge.40
19 Magnetic stray field.40
19.1 Characteristic to be specified.40
19.2 Method of measurement .40
20 Physical characteristics.40
20.1 Dimensions .40
20.2 Weight.40
20.3 Cables and connectors .40
21 Classification of the characteristics to be specified.40
21.1 General .40
Annex A (normative) Sound insulation device .43
Annex B (informative) Simplified procedure for “pop” measurements .44
Annex C (informative) Supplement for digital microphones .47
Bibliography .49
Figure 1 – Balance of the output.30
Figure 2 – Balance under working conditions .31
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60268-4 © IEC:2010 – 5 –
Figure 3 – Measurement set-up for wind influence .35
Figure 4 – Wind generators, type 1 (Figure 4a) and type 2 (Figure 4b)).36
Figure 5 – Electrical and mechanical set-up for the measuring of the "pop" effect .38
Figure A.1 – Sound insulation device.43
Figure B.1 – Measurement set-up.45
Figure B.2 – Test fixture for the sound field sensitivity .46
Table 1 – Reverberation time of the empty room.14
Table 2 – Speech power weighting factor at octave-band centre frequencies .22
Table 3 – Reference signal and characteristics.39
Table 4 – Classification of characteristics .42
Table C.1 – Classification of the characteristics to be specified .47
Table C.2 – Additional digital characteristics to be specified .48
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SOUND SYSTEM EQUIPMENT –
Part 4: Microphones
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60268-4 has been prepared by IEC technical committee 100: Audio,
video and multimedia systems and equipment.
This fourth edition cancels and replaces the third edition published in 2004, and constitutes a
technical revision.
The main changes with respect to the previous edition are the following:
– correction of noise measurement,
– added annex for digital microphones,
– added requirement for tolerances in data to be specified.
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60268-4 © IEC:2010 – 7 –
This bilingual version (2010-09) replaces the English version.
The text of this standard is based on the following documents:
FDIS Report on voting
100/1678/FDIS 100/1707/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60268 series, under the general title “Sound system equipment”,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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– 8 – 60268-4 © IEC:2010
SOUND SYSTEM EQUIPMENT –
Part 4: Microphones
1 Scope
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 measuremen
...
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