IEC 60268-4:2018

Sound system equipment - Part 4: Microphones

IEC 60268-4:2018 is available as IEC 60268-4:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60268-4:2018 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. The major characteristics of a microphone are considered in Clauses 6 to 21. Additional characteristics are considered in Annex A and Annex C. IEC 60268-4:2018 cancels and replaces the fifth edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) subclause 19.4 on "pop" measurement replaces Annex C;
b) new Annex D for noise measurements in the digital domain.

Équipements pour systèmes électroacoustiques - Partie 4: Microphones

IEC 60268-4:2018 est disponible sous forme de IEC 60268-4:2018 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.
IEC 60268-4:2018 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 décrit également les caractéristiques à spécifier par le fabricant.
Elle s’applique aux microphones pour les systèmes électroacoustiques appartenant aux applications relatives à la parole et à la musique. Elle ne s’applique pas aux microphones de mesure, mais elle s’applique à chaque voie audio des microphones multivoies, par exemple pour une utilisation stéréophonique ou similaire. Elle est également applicable aux microphones à montage encastré et aux caractéristiques analogiques des microphones à sortie audio numérique.
Pour les besoins de la présente Norme internationale, un microphone comprend tous les dispositifs, tels que les transformateurs, préamplificateurs ou autres éléments faisant partie intégrante du microphone, jusqu’aux bornes de sortie spécifiées par le fabricant.
Les principales caractéristiques d’un microphone sont examinées dans les Articles 6 à 21. Des caractéristiques supplémentaires sont étudiées dans l’Annexe A et l’Annexe C
IEC 60268-4:2018 annule et remplace la cinquième édition parue en 2014. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) le paragraphe 19.4 relatif à la mesure de l’effet "pop" remplace l’Annexe C;
b) nouvelle Annexe D pour les mesures du bruit dans le domaine numérique.

General Information

• Status: Published
• Publication Date: 11-Sep-2018
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 33.160.50 - Accessories
• Technical Committee: TA 20 - Analogue and digital audio
• Drafting Committee: MT 60268-4 - TC 100/TA 20/MT 60268-4
• Current Stage: PPUB - Publication issued
• Start Date: 31-Aug-2018
• Completion Date: 12-Sep-2018

Relations

• Revises: IEC 60268-4:2014 - Sound system equipment - Part 4: Microphones
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60268-4 ®
Edition 6.0 2018-09
INTERNATIONAL
STANDARD
Sound system equipment –
Part 4: Microphones
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 IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
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.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
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documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
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IEC 60268-4 ®
Edition 6.0 2018-09
INTERNATIONAL
STANDARD
Sound system equipment –
Part 4: Microphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160.50 ISBN 978-2-8322-5955-9

– 2 – IEC 60268-4:2018 © IEC 2018
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references. 8
3 Terms and definitions . 9
4 General conditions . 10
4.1 General . 10
4.2 Measurement conditions . 10
4.2.1 General . 10
4.2.2 Rated conditions . 11
5 Particular conditions . 12
5.1 Pre-conditioning . 12
5.2 Sound source . 12
5.3 Measurement of sound pressure . 12
5.4 Voltage measuring system . 12
5.5 Acoustical environment . 12
5.5.1 General . 12
5.5.2 Free-field conditions . 13
5.5.3 Diffuse field conditions . 14
5.5.4 Microphone coupled to a sound source by means of a small cavity
coupler . 15
5.6 Methods of measuring frequency response . 15
5.6.1 Point-by-point and continuous sweep frequency methods . 15
5.6.2 Calibration methods . 16
5.7 Overall accuracy . 16
5.8 Graphical presentation of results . 16
6 Type description (acoustical behaviour) . 17
6.1 Principle of the transducer . 17
6.2 Type of microphone . 17
6.3 Type of directional response characteristics . 17
6.4 Application . 17
7 Terminals and controls. 17
7.1 Marking . 17
7.2 Connectors and electrical interface values . 17
8 Reference point and axis . 18
8.1 Reference point . 18
8.2 Reference axis . 18
9 Rated power supply . 18
9.1 Characteristics to be specified . 18
9.2 Method of measurement . 18
10 Electrical impedance . 18
10.1 Internal impedance . 18
10.1.1 Characteristic to be specified . 18
10.1.2 Methods of measurement . 18
10.2 Rated impedance . 19
10.3 Rated minimum permitted load impedance . 19

11 Sensitivity . 19
11.1 General . 19
11.2 Sensitivities with respect to acoustical environment . 20
11.2.1 Free-field sensitivity . 20
11.2.2 Diffuse-field sensitivity . 21
11.2.3 Close-talking and near-field sensitivity . 21
11.2.4 Pressure sensitivity . 22
11.3 Rated sensitivity . 22
12 Response . 22
12.1 Frequency response . 22
12.1.1 Characteristic to be specified . 22
12.1.2 Method of measurement . 23
12.1.3 Graphical presentation of results . 23
12.2 Effective frequency range . 23
12.2.1 Characteristic to be specified . 23
12.2.2 Method of measurement . 23
13 Directional characteristics . 23
13.1 Directional pattern . 23
13.1.1 Characteristic to be specified . 23
13.1.2 Methods of measurement . 24
13.1.3 Graphical presentation of results . 25
13.2 Directivity index . 25
13.2.1 Characteristic to be specified . 25
13.2.2 Method of measurement . 25
14 Amplitude non-linearity . 25
14.1 General . 25
14.2 Total harmonic distortion . 25
14.2.1 Characteristic to be specified . 25
14.2.2 Method of measurement . 26
th
14.3 Harmonic distortion of the n order (n = 2, 3,.) . 26
14.3.1 Characteristic to be specified . 26
14.3.2 Method of measurement . 26
14.4 Difference frequency distortion of second order . 27
14.4.1 Characteristic to be specified . 27
14.4.2 Method of measurement . 27
15 Limiting characteristics . 28
15.1 Rated maximum permissible peak sound pressure . 28
15.2 Overload sound pressure . 28
15.2.1 Characteristic to be specified . 28
15.2.2 Method of measurement . 28
16 Balance . 28
16.1 Balance of the microphone output . 28
16.2 Balance under working conditions . 29
17 Equivalent sound pressure level due to inherent noise . 29
17.1 Characteristic to be specified . 29
17.2 Method of measurement . 29
18 Ambient conditions . 30
18.1 General . 30

– 4 – IEC 60268-4:2018 © IEC 2018
18.2 Pressure range . 30
18.3 Temperature range .
...

IEC 60268-4 ®
Edition 6.0 2018-09
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Sound system equipment –
Part 4: Microphones
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 IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
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.

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The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

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The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

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also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC 60268-4 ®
Edition 6.0 2018-09
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Sound system equipment –
Part 4: Microphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160.50 ISBN 978-2-8322-6047-0

– 2 – IEC 60268-4:2018 RLV © IEC 2018
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references. 8
3 Terms and definitions . 9
4 General conditions . 10
4.1 General . 10
4.2 Measurement conditions . 10
4.2.1 General . 10
4.2.2 Rated conditions . 11
5 Particular conditions . 12
5.1 Pre-conditioning . 12
5.2 Sound source . 12
5.3 Measurement of sound pressure . 12
5.4 Voltage measuring system . 12
5.5 Acoustical environment . 12
5.5.1 General . 12
5.5.2 Free-field conditions . 13
5.5.3 Diffuse field conditions . 15
5.5.4 Microphone coupled to a sound source by means of a small cavity
coupler . 15
5.6 Methods of measuring frequency response . 16
5.6.1 Point-by-point and continuous sweep frequency methods . 16
5.6.2 Calibration methods . 16
5.7 Overall accuracy . 17
5.8 Graphical presentation of results . 17
6 Type description (acoustical behaviour) . 17
6.1 Principle of the transducer . 17
6.2 Type of microphone . 17
6.3 Type of directional response characteristics . 17
6.4 Application . 17
7 Terminals and controls. 17
7.1 Marking . 17
7.2 Connectors and electrical interface values . 18
8 Reference point and axis . 18
8.1 Reference point . 18
8.2 Reference axis . 18
9 Rated power supply . 18
9.1 Characteristics to be specified . 18
9.2 Method of measurement . 18
10 Electrical impedance . 19
10.1 Internal impedance . 19
10.1.1 Characteristic to be specified . 19
10.1.2 Methods of measurement . 19
10.2 Rated impedance . 19
10.3 Rated minimum permitted load impedance . 20

11 Sensitivity . 20
11.1 General . 20
11.2 Sensitivities with respect to acoustical environment . 20
11.2.1 Free-field sensitivity . 20
11.2.2 Diffuse-field sensitivity . 21
11.2.3 Close-talking or and near-field sensitivity . 22
11.2.4 Pressure sensitivity . 22
11.3 Rated sensitivity . 22
12 Response . 23
12.1 Frequency response . 23
12.1.1 Characteristic to be specified . 23
12.1.2 Method of measurement . 23
12.1.3 Graphical presentation of results . 23
12.2 Effective frequency range . 23
12.2.1 Characteristic to be specified . 23
12.2.2 Method of measurement . 23
13 Directional characteristics . 24
13.1 Directional pattern . 24
13.1.1 Characteristic to be specified . 24
13.1.2 Methods of measurement . 24
13.1.3 Graphical presentation of results . 25
13.2 Directivity index . 25
13.2.1 Characteristic to be specified . 25
13.2.2 Method of measurement . 25
14 Amplitude non-linearity . 26
14.1 General . 26
14.2 Total harmonic distortion . 26
14.2.1 Characteristic to be specified . 26
14.2.2 Method of measurement . 26
th
14.3 Harmonic distortion of the n order (n = 2, 3,.) . 27
14.3.1 Characteristic to be specified . 27
14.3.2 Method of measurement . 27
14.4 Difference frequency distortion of second order . 27
14.4.1 Characteristic to be specified . 27
14.4.2 Method of measurement . 27
15 Limiting characteristics . 28
15.1 Rated maximum permissible peak sound pressure . 28
15.2 Overload sound pressure . 28
15.2.1 Characteristic to be specified . 28
15.2.2 Method of measurement . 28
16 Balance . 29
16.1 Balance of the microphone output . 29
16.2 Balance under working conditions . 29
17 Equivalent sound pressure level due to inherent noise . 30
17.1 Characteristic to be specified . 30
17.2 Method of measurement . 30
18 Ambient conditions . 30
18.1 General . 30

– 4 – IEC 60268-4:2018 RLV © IEC 2018
18.2 Pressure range .
...

IEC 60268-4 ®
Edition 6.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 4: Microphones
Équipements pour systèmes électroacoustiques –
Partie 4: Microphones
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 IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

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IEC 60268-4 ®
Edition 6.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 4: Microphones
Équipements pour systèmes électroacoustiques –

Partie 4: Microphones
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.160.50 ISBN 978-2-8322-6616-8

– 2 – IEC 60268-4:2018 © IEC 2018
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General conditions. 10
4.1 General . 10
4.2 Measurement conditions . 10
4.2.1 General . 10
4.2.2 Rated conditions . 11
5 Particular conditions . 12
5.1 Pre-conditioning . 12
5.2 Sound source . 12
5.3 Measurement of sound pressure . 12
5.4 Voltage measuring system . 12
5.5 Acoustical environment . 12
5.5.1 General . 12
5.5.2 Free-field conditions . 13
5.5.3 Diffuse field conditions . 14
5.5.4 Microphone coupled to a sound source by means of a small cavity
coupler . 15
5.6 Methods of measuring frequency response . 15
5.6.1 Point-by-point and continuous sweep frequency methods . 15
5.6.2 Calibration methods . 16
5.7 Overall accuracy . 16
5.8 Graphical presentation of results. 16
6 Type description (acoustical behaviour) . 17
6.1 Principle of the transducer . 17
6.2 Type of microphone . 17
6.3 Type of directional response characteristics . 17
6.4 Application . 17
7 Terminals and controls . 17
7.1 Marking . 17
7.2 Connectors and electrical interface values . 17
8 Reference point and axis . 18
8.1 Reference point . 18
8.2 Reference axis . 18
9 Rated power supply . 18
9.1 Characteristics to be specified . 18
9.2 Method of measurement . 18
10 Electrical impedance . 18
10.1 Internal impedance . 18
10.1.1 Characteristic to be specified . 18
10.1.2 Methods of measurement . 18
10.2 Rated impedance . 19
10.3 Rated minimum permitted load impedance . 19

11 Sensitivity . 19
11.1 General . 19
11.2 Sensitivities with respect to acoustical environment . 20
11.2.1 Free-field sensitivity . 20
11.2.2 Diffuse-field sensitivity . 21
11.2.3 Close-talking and near-field sensitivity . 21
11.2.4 Pressure sensitivity . 22
11.3 Rated sensitivity . 22
12 Response . 22
12.1 Frequency response . 22
12.1.1 Characteristic to be specified . 22
12.1.2 Method of measurement . 23
12.1.3 Graphical presentation of results . 23
12.2 Effective frequency range . 23
12.2.1 Characteristic to be specified . 23
12.2.2 Method of measurement . 23
13 Directional characteristics . 23
13.1 Directional pattern . 23
13.1.1 Characteristic to be specified . 23
13.1.2 Methods of measurement . 24
13.1.3 Graphical presentation of results . 25
13.2 Directivity index . 25
13.2.1 Characteristic to be specified . 25
13.2.2 Method of measurement . 25
14 Amplitude non-linearity . 25
14.1 General . 25
14.2 Total harmonic distortion . 25
14.2.1 Characteristic to be specified . 25
14.2.2 Method of measurement .
...