Sound system equipment -- Part 4: Microphones

Specifies methods of measurement for the electrical impedance, sensitivity, directional response pattern, dynamic range and external influences of sound system microphones, and also gives recommendations as to characteristics to be specified. It applies to sound system microphones for all applications for speech and music

Elektroakustische Geräte -- Teil 4: Mikrofone

Equipements pour systèmes électroacoustiques -- Partie 4: Microphones

Specifies methods of measurement for the electrical impedance, sensitivity, directional response pattern, dynamic range and external influences of sound system microphones, and also gives recommendations as to characteristics to be specified. It applies to sound system microphones for all applications for speech and music

Elektroakustične naprave – 4. del: Mikrofoni (IEC 60268-4:2004)*

General Information

Status
Published
Publication Date
31-Aug-2004
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Sep-2004
Due Date
01-Sep-2004
Completion Date
01-Sep-2004

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SLOVENSKI SIST EN 60268-4:2004
STANDARD
september 2004
Elektroakustične naprave – 4. del: Mikrofoni (IEC 60268-4:2004)*
Sound system equipment - Part 4: Microphones (IEC 60268-4:2004)
ICS 33.160.50 Referenčna številka
SIST EN 60268-4:2004(en)

© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------
EUROPEAN STANDARD EN 60268-4
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2004
ICS 33.160.50 Supersedes EN 60268-4:1999
English version
Sound system equipment
Part 4: Microphones
(IEC 60268-4:2004)
Equipements pour systèmes Elektroakustische Geräte
électroacoustiques Teil 4: Mikrofone
Partie 4: Microphones (IEC 60268-4:2004)
(CEI 60268-4:2004)

This European Standard was approved by CENELEC on 2004-03-01. CENELEC members are bound to

comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CENELEC member into its own language and

notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech

Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,

Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60268-4:2004 E
---------------------- Page: 2 ----------------------
EN 60268-4:2004 - 2 -
Foreword

The text of document 100/721/FDIS, future edition 3 of IEC 60268-4, prepared by IEC TC 100, Audio,

video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and

was approved by CENELEC as EN 60268-4 on 2004-03-01.
This European Standard supersedes EN 60268-4:1999
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2004-12-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-03-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 60268-4:2004 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60574-1 NOTE Harmonized as HD 369.1 S1:1978 (not modified)
IEC 61672-1 NOTE Harmonized as EN 61672-1:2003 (not modified)
__________
---------------------- Page: 3 ----------------------
- 3 - EN 60268-4:2004
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.

NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
Publication Year Title EN/HD Year
IEC 60065 (mod) 2001 Audio, video and similar electronic EN 60065 2002
apparatus - Safety requirements
IEC 60268-1 1985 Sound system equipment HD 483.1 S2 1989
Part 1: General
IEC 60268-2 1987 Part 2: Explanation of general terms and HD 483.2 S2 1993
calculation methods
IEC 60268-3 2000 Part 3: Amplifiers EN 60268-3 2000
+ corr. January 2002
IEC 60268-5 2003 Part 5: Loudspeakers EN 60268-5 2003
IEC 60268-11 1987 Part 11: Application of connectors for HD 483.11 S3 1993
the interconnection of sound system
components
IEC 60268-12 1987 Part 12: Application of connectors for EN 60268-12 1995
broadcast and similar use
IEC 60574-3 1983 Audiovisual, video and television HD 369.3 S1 1986
equipment and systems
Part 3: Connectors for the
interconnection of equipment in audio-
visual systems
IEC 60914 1988 Conference systems - Electrical and HD 549 S1 1989
audio requirements
IEC 61000-4-2 1995 Electromagnetic compatibility (EMC) EN 61000-4-2 1995
Part 4-2: Testing and measurement
techniques - Electrostatic discharge
immunity test
HD 483.1 S2 includes A1:1988 to IEC 60268-1.
HD 483.2 S2 includes A1:1991 to IEC 60268-2.
HD 483.11 S3 includes A1:1989 + A2:1991 to IEC 60268-11.
EN 60268-12 includes A1:1991 to IEC 60268-12.
---------------------- Page: 4 ----------------------
EN 60268-4:2004 - 4 -
Publication Year Title EN/HD Year
IEC 61000-4-3 2002 Part 4-3: Testing and measurement EN 61000-4-3 2002
techniques - Radiated, radio-frequency,
electromagnetic field immunity test
IEC 61265 1995 Electroacoustics - Instruments for EN 61265 1995
measurement of aircraft noise -
Performance 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 - EN 61938 1997
Interconnections and matching values - + corr. February 1997
Preferred matching values of analogue
signals
ISO 354 2003 Acoustics - Measurement of sound EN ISO 354 2003
absorption in a reverberation room
---------------------- Page: 5 ----------------------
INTERNATIONAL IEC
STANDARD
60268-4
Third edition
2004-02
Sound system equipment –
Part 4:
Microphones
 IEC 2004  Copyright - all rights reserved

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 the publisher.

International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland

Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch

PRICE CODE
Commission Electrotechnique Internationale X
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
---------------------- Page: 6 ----------------------
– 2 – 60268-4  IEC:2004(E)
CONTENTS

FOREWORD...........................................................................................................................5

1 Scope...............................................................................................................................7

2 Normative references........................................................................................................7

3 General conditions............................................................................................................8

3.1 General ...................................................................................................................8

3.2 Measurement conditions ..........................................................................................8

4 Particular conditions .........................................................................................................9

4.1 Pre-conditioning ......................................................................................................9

4.2 Sound source ........................................................................................................10

4.3 Measurement of sound pressure............................................................................10

4.4 Voltage measuring system .....................................................................................10

4.5 Acoustical environment..........................................................................................10

4.6 Methods of measuring frequency response ............................................................13

4.7 Overall accuracy....................................................................................................14

4.8 Graphical presentation of results............................................................................14

5 Type description (acoustical behaviour)...........................................................................14

5.1 Principle of the transducer .....................................................................................14

5.2 Type of microphone ...............................................................................................14

5.3 Type of directional response characteristics...........................................................14

6 Terminals and controls....................................................................................................15

6.1 Marking .................................................................................................................15

6.2 Connectors and electrical interface values .............................................................15

7 Reference point and axis ................................................................................................15

7.1 Reference point .....................................................................................................15

7.2 Reference axis ......................................................................................................15

8 Rated power supply ........................................................................................................15

8.1 Characteristic to be specified.................................................................................15

8.2 Method of measurement ........................................................................................16

9 Electrical impedance.......................................................................................................16

9.1 Internal impedance ................................................................................................16

9.2 Rated impedance...................................................................................................17

9.3 Minimum permitted load impedance .......................................................................17

10 Sensitivity.......................................................................................................................17

10.1 General .................................................................................................................17

10.2 Sensitivities with respect to acoustical environment................................................18

10.3 Sensitivities with respect to nature of signal ...........................................................20

11 Response .......................................................................................................................21

11.1 Frequency response ..............................................................................................21

11.2 Effective frequency range ......................................................................................21

12 Directional characteristics ...............................................................................................22

12.1 Directional pattern .................................................................................................22

12.2 Directivity index .....................................................................................................23

12.3 Front-to-rear sensitivity index (0° – 180°) ...............................................................23

12.4 Noise-cancelling index ...........................................................................................24

12.5 Special characteristics for stereo microphones.......................................................24

---------------------- Page: 7 ----------------------
60268-4 © IEC:2004(E) – 3 –

13 Amplitude non-linearity ...................................................................................................25

13.1 General .................................................................................................................25

13.2 Total harmonic distortion .......................................................................................26

13.3 Harmonic distortion of the n order (n = 2, 3,...).....................................................26

13.4 Difference frequency distortion of second order......................................................27

14 Limiting characteristics ...................................................................................................28

14.1 Rated maximum permissible peak sound pressure.................................................28

14.2 Overload sound pressure.......................................................................................28

15 Balance ..........................................................................................................................28

15.1 Balance of the microphone output..........................................................................28

15.2 Balance under working conditions ..........................................................................28

16 Equivalent sound pressure level due to inherent noise.....................................................29

16.1 Characteristic to be specified.................................................................................29

16.2 Method of measurement ........................................................................................29

17 Ambient conditions .........................................................................................................29

17.1 General .................................................................................................................29

17.2 Pressure range......................................................................................................29

17.3 Temperature range ................................................................................................29

17.4 Relative humidity range .........................................................................................29

18 External influences .........................................................................................................30

18.1 General .................................................................................................................30

18.2 Equivalent sound pressure due to external magnetic fields.....................................30

18.3 Equivalent sound pressure due to mechanical vibration..........................................31

18.4 Equivalent sound pressure due to wind ..................................................................32

18.5 Transient equivalent sound pressure due to "pop" effect ........................................33

18.6 Equivalent sound pressure due to electromagnetic interference..............................34

18.7 Electrostatic discharge...........................................................................................34

19 Magnetic stray field.........................................................................................................34

19.1 Characteristic to be specified.................................................................................34

19.2 Method of measurement ........................................................................................35

20 Physical characteristics...................................................................................................35

20.1 Dimensions ...........................................................................................................35

20.2 Weight...................................................................................................................35

20.3 Cables and connectors ..........................................................................................35

21 Classification of the characteristics to be specified..........................................................35

21.1 General .................................................................................................................35

21.2 Classification.........................................................................................................36

Annex A (normative) Sound insulation device ........................................................................41

Annex B (informative) Simplified procedure for “pop” measurements .....................................42

Bibliography ..........................................................................................................................45

Figure 1a – Balance of the output..........................................................................................37

Figure 1b – Balance under working conditions .......................................................................37

Figure 2 – Measurement set-up for wind influence .................................................................37

Figure 3a – Wind generator with radial fan (front and side view) ............................................38

---------------------- Page: 8 ----------------------
– 4 – 60268-4  IEC:2004(E)

Figure 3b – Wind generator with axial fan..............................................................................38

Figure 4 – Electrical and mechanical set-up for the measuring of the "pop" effect ..................39

Figure 5 – Reference signal and characteristics.....................................................................40

Figure A.1 – Sound insulation device.....................................................................................41

Figure B.1 – Measurement set-up..........................................................................................43

Figure B.2 – Test fixture for the sound field sensitivity ...........................................................44

Table 1 – Reverberation time of the empty room....................................................................12

Table 2 – Speech power weighting factor at octave-band centre frequencies .........................20

Table 3 – Classification of characteristics ..............................................................................36

---------------------- Page: 9 ----------------------
60268-4 © IEC:2004(E) – 5 –
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,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with an IEC Publication.

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 third edition cancels and replaces the second edition published in 1997, and constitutes a

technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
100/721/FDIS 100/750/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.

---------------------- Page: 10 ----------------------
– 6 – 60268-4  IEC:2004(E)

The committee has decided that the contents of this publication will remain unchanged until

2008. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
---------------------- Page: 11 ----------------------
60268-4 © IEC:2004(E) – 7 –
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 gives recommendations as to characteristics to be specified.

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 use 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

IEC 60268-1:1985, Sound system equipment – Part 1: General

IEC 60268-2:1987, Sound system equipment – Part 2: Explanation of general terms and

calculation methods
IEC 60268-3:2000, Sound system equipment – Part 3: Amplifiers
IEC 60268-5:2003, Sound system equipment – Part 5: Loudspeakers

IEC 60268-11:1987, Sound system equipment – Part 11: Application of connectors for the

interconnection of sound system components

IEC 60268-12:1987, Sound system equipment – Part 12: Application of connectors for

broadcast and similar use

IEC 60574-3:1983, Audiovisual, video and television equipment and systems – Part 3:

Connectors for the interconnection of equipment in audiovisual systems
IEC 60914:1988, Conference systems – Electrical and audio requirements
---------------------- Page: 12 ----------------------
– 8 – 60268-4  IEC:2004(E)

IEC 61000-4-2:1995, Electromagnetic compatibility (EMC) – Part 4-2: Testing and measure-

ment techniques – Electrostatic discharge immunity test

IEC 61000-4-3:2002, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement

techniques – Section 3: Radiated, radio-frequency, electromagnetic field immunity test

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 coefficients in a reverberant room

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 specifications and type specifications;
• graphical presentation of characteristics;
• scales for graphical presentation;
• personal safety and prevention of spread of fire;
• method of producing a uniform alternating magnetic field;
• search coils for measuring the magnetic field strength,
and to IEC 61938 concerning powering of microphones.
3.2 Measurement conditions
3.2.1 Introduction

For convenience in specifying how microphones shall be set up for measurement, a set of

conditions has been defined in this recommendation under the title of "rated conditions".

Three ratings are basic to the formulation of these concepts:
– rated impedance (see 9.2);
– rated power supply (see 8.1);
– rated sensitivity (see 10.3.1).

To obtain the correct conditions for measurement, the above mentioned ratings shall be taken

from the specifications supplied by the manufacturer of the equipment.
---------------------- Page: 13 ----------------------
60268-4 © IEC:2004(E) – 9 –

The term "rated" applied to other characteristics relates to the specification or measurement of

the particular characteristic under rated conditions or under conditions unambiguously

connected to them. This applies, for example, to the following two characteristics:

– rated output voltage;
– rated equivalent sound pressure level due to inherent noise.

Methods of measurement are given in this standard for electrical impedance, sensitivity,

directional pattern, dynamic range and external influences. Where alternative methods are

given, the chosen method shall be specified.
3.2.2 Rated conditions

The microphone is understood to be working under rated conditions when the following

conditions are fulfilled:
– the microphone shall operate at no-load condition (see 9.2);
– if the microphone needs a power supply, this shall be the rated power supply;

– the microphone (except a close-talking microphone) shall be placed in a free sound field,

the waves having zero degree incidence with respect to the reference direction;

– the undisturbed sound pressure (in the absence of the microphone) in the sound field at the

reference point of the microphone shall be sinusoidal and set at a level of 0,3 Pa (84 dB SPL)

– for close-talking microphones, the microphone shall be placed at a stated distance, no

more than 25 mm from the artificial mouth, and the undisturbed sound pressure in the

sound field at the reference point of microphone shall be sinusoidal and set at a level of

3 Pa (104 dB SPL).

– if a special microphone needs a different measurement level, this shall be stated in the

technical data together with the reason for this. Levels related to the normal reference level

of 94 dB by multiples of 10 dB are preferred;

– controls, if any, shall be set to the position recommended by the manufacturer;

– in the absence of a clear reason to the contrary, the measurement frequency shall

be 1000 Hz (see IEC 60268-1);

– the ambient pressure, the relative humidity and the ambient temperature shall be within the

...

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