Sound system equipment - Part 21: Acoustical (output-based) measurements (IEC 60268-21:2018)

This part of IEC 60268 specifies an acoustical measurement method that applies to electroacoustical
transducers and passive and active sound systems, such as loudspeakers, TV-sets,
multi-media devices, personal portable audio devices, automotive sound systems and
professional equipment. The device under test (DUT) can be comprised of electrical
components performing analogue and digital signal processing prior to the passive actuators
performing a transduction of the electrical input into an acoustical output signal. This
document describes only physical measurements that assess the transfer behaviour of the
DUT between an arbitrary analogue or digital input signal and the acoustical output at any
point in the near and far field of the system. This includes operating the DUT in both the small
and large signal domains. The influence of the acoustical boundary conditions of the target
application (e.g. car interior) can also be considered in the physical evaluation of the sound
system. This document does not assess the perception and cognitive evaluation of the
reproduced sound and the impact of perceived sound quality.
NOTE Some measurement methods defined in this document can be applied to headphones, headsets,
earphones and earsets in accordance with [1]1. This document does not apply to microphones and other sensors.
This document does not require access to the state variables (voltage, current) at the electrical terminals of the
transducer. Sensitivity, electric input power and other characteristics based on the electrical impedance will be
described in a separate future standard document, IEC 60268-22, dedicated to electrical and mechanical
measurements.

Elektroakustische Geräte - Teil 21: Akustische(Ausgabebasierte) Messungen (IEC 60268-21:2018)

Équipements pour systèmes électroacoustiques - Partie 21 : Mesures acoustiques (en sortie) (IEC 60268-21:2018)

IEC 60268-21:2018 spécifie une méthode de mesure acoustique qui s’applique aux transducteurs électroacoustiques ainsi qu’aux systèmes électroacoustiques passifs et actifs tels que les haut-parleurs, les téléviseurs, les appareils multimédias, les appareils audio personnels portables, les systèmes électroacoustiques pour automobile et les équipements professionnels. L'appareil soumis à essai (DUT) peut être constitué de composants électriques qui effectuent un traitement analogique et numérique des signaux avant la transduction de l’entrée électrique en un signal de sortie acoustique par les excitateurs passifs. Le présent document décrit uniquement les mesures physiques qui évaluent le comportement de transfert du DUT entre un signal d’entrée analogique ou numérique arbitraire et la sortie acoustique en un point quelconque dans le champ proche et lointain du système. Cela inclut le fonctionnement du DUT dans les domaines à la fois des signaux faibles et des signaux forts. L’influence des conditions de limite acoustique de l’application visée (par exemple habitacle de véhicule) peut également être prise en considération dans l’évaluation physique du système électroacoustique. Le présent document n’évalue pas la perception et l’évaluation cognitive du son reproduit ni l’impact de la qualité perçue du son.

Elektroakustične naprave - 21. del: Akustične (izhodne) meritve (IEC 60268-21:2018)

Ta del standarda IEC 60268 določa metodo akustične meritve, ki se uporablja za elektroakustične
pretvornike ter pasivne in aktivne zvočne sisteme, kot so zvočniki, televizorji, večpredstavnostne naprave, osebne prenosne zvočne naprave, avtomobilski zvočni sistemi in profesionalna oprema. Napravo, ki se preskuša (DUT), lahko sestavljajo električne komponente, ki obdelujejo analogni in digitalni signal pred pasivnimi aktuatorji, ki pretvarjajo električni vhodni signal v akustični izhodni signal. Ta dokument opisuje samo fizične meritve za ocenjevanje prenosnega delovanja naprave, ki se preskuša, med poljubnim analognim ali digitalnim vhodnim signalom ter akustičnim izhodnim signalom na kateri koli točki bližnjega in daljnega polja sistema. To vključuje delovanje naprave, ki se preskuša, tako v domenah majhnega kot velikega signala. Pri fizični oceni zvočnega sistema je mogoče upoštevati tudi vpliv akustičnih mejnih pogojev ciljne uporabe (npr. notranjost avtomobila). Ta dokument se ne uporablja za ocenjevanje zaznavanja ter kognitivno vrednotenje
reproduciranega zvoka in vpliva zaznane kakovosti zvoka.
OPOMBA: Nekatere merilne metode, opredeljene v tem dokumentu, je mogoče uporabiti za slušalke, telefone, ušesne slušalke in druge komplete v skladu z določbo [1]1. Ta dokument se ne uporablja za mikrofone in druge senzorje.
Ta dokument ne zahteva dostopa do spremenljivk stanja (napetost, tok) na električnih terminalih pretvornika. Občutljivost, električna vhodna moč in druge značilnosti na podlagi električne impedance bodo opisane v ločenem prihodnjem dokumentu standarda IEC 60268-22, namenjenem električnim in mehanskim meritvam.

General Information

Status
Published
Publication Date
02-Sep-2019
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
27-Dec-2018
Due Date
03-Mar-2019
Completion Date
03-Sep-2019

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SLOVENSKI STANDARD
SIST EN IEC 60268-21:2019
01-oktober-2019
Elektroakustične naprave - 21. del: Akustične (izhodne) meritve (IEC 60268-
21:2018)
Sound system equipment - Part 21: Acoustical (output-based) measurements (IEC
60268-21:2018)

Elektroakustische Geräte - Teil 21: Akustische(Ausgabebasierte) Messungen (IEC 60268

-21:2018)

Équipements pour systèmes électroacoustiques - Partie 21 : Mesures acoustiques (en

sortie) (IEC 60268-21:2018)
Ta slovenski standard je istoveten z: EN IEC 60268-21:2018
ICS:
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
33.160.01 Avdio, video in avdiovizualni Audio, video and audiovisual
sistemi na splošno systems in general
SIST EN IEC 60268-21:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60268-21:2019
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SIST EN IEC 60268-21:2019
EUROPEAN STANDARD EN IEC 60268-21
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2018
ICS 33.160.01
English Version
Sound system equipment - Part 21: Acoustical (output-based)
measurements
(IEC 60268-21:2018)

Équipements pour systèmes électroacoustiques - Partie 21 Elektroakustische Geräte - Teil 21:

: Mesures acoustiques (en sortie) Akustische(Ausgabebasierte) Messungen
(IEC 60268-21:2018) (IEC 60268-21:2018)

This European Standard was approved by CENELEC on 2018-12-12. 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 CEN-CENELEC

Management Centre 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 CEN-CENELEC Management Centre has the

same status as the official versions.

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

Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

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

Switzerland, Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 60268-21:2018 E
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SIST EN IEC 60268-21:2019
EN IEC 60268-21:2018 (E)
European foreword

The text of document 100/2957/CDV, future edition 1 of IEC 60268-21, prepared by IEC/TC 100

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

vote and approved by CENELEC as EN IEC 60268-21:2018.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2019-09-12

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2021-12-12

document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice

The text of the International Standard IEC 60268-21:2018 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 60268-7:2010 NOTE Harmonized as EN 60268-7:2011 (not modified)
IEC 62777 NOTE Harmonized as EN 62777
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SIST EN IEC 60268-21:2019
EN IEC 60268-21:2018 (E)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:

www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60263 - Scales and sizes for plotting frequency characteristics - -
and polar diagrams
IEC 60268-1 - Sound system equipment. Part 1: General HD 483.1 S2 -

IEC 60268-2 1987 Sound system equipment. Part 2: Explanation of HD 483.2 S2 1993

general terms and calculation methods
IEC 61094-4 - Measurement microphones - Part 4: Specifications EN 61094-4 -
for working standard microphones

IEC 61260-1 - Electroacoustics - Octave-band and fractional-octave- EN 61260-1 -

band filters - Part 1: Specifications
ISO 3 - Preferred numbers - Series of preferred numbers - -

ISO 3741 2010 Acoustics - Determination of sound power levels and EN ISO 3741 2010

sound energy levels of noise sources using sound
pressure - Precision methods for reverberation test
rooms
ISO 3744 - Acoustics - Determination of sound power levels and EN ISO 3744 -
sound energy levels of noise sources using sound
pressure - Engineering methods for an essentially
free field over a reflecting plane
ISO 3745 - Acoustics - Determination of sound power levels and EN ISO 3745 -
sound energy levels of noise sources using sound
pressure - Precision methods for anechoic rooms and
hemi-anechoic rooms
CTA 2034-A - Standard Method of Measurement for In-Home - -
Loudspeakers, Consumer Technology Association
(Formerly CEA)
CTA 2010-B - Standard Method of Measurement for Powered - -
Subwoofers, standard by Consumer Technology
Association (Formerly CEA)
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SIST EN IEC 60268-21:2019
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SIST EN IEC 60268-21:2019
IEC 60268-21
Edition 1.0 2018-11
INTERNATIONAL
STANDARD
colour
inside
Sound system equipment –
Part 21: Acoustical (output-based) measurements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160.01 ISBN 978-2-8322-6176-7

Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
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SIST EN IEC 60268-21:2019
– 2 – IEC 60268-21:2018  IEC 2018
CONTENTS

FOREWORD ........................................................................................................................... 8

INTRODUCTION ................................................................................................................... 10

1 Scope ............................................................................................................................ 11

2 Normative references .................................................................................................... 11

3 Terms, definitions and abbreviated terms ...................................................................... 12

3.1 Terms and definitions ............................................................................................ 12

3.2 Abbreviated terms ................................................................................................. 12

4 Type description ............................................................................................................ 12

5 Physical characteristics ................................................................................................. 12

5.1 Marking of terminals and controls ......................................................................... 12

5.2 Dimensions ........................................................................................................... 12

5.3 Mass ..................................................................................................................... 12

5.4 Connectors and cable assemblies ......................................................................... 13

6 Design data ................................................................................................................... 13

7 Conditions ..................................................................................................................... 13

7.1 Rated conditions ................................................................................................... 13

7.2 Climatic conditions ................................................................................................ 13

7.3 Normal measuring conditions ................................................................................ 13

8 Test signals ................................................................................................................... 14

8.1 General ................................................................................................................. 14

8.2 Sinusoidal chirp .................................................................................................... 14

8.3 Steady-state single-tone signal ............................................................................. 15

8.4 Steady-state two-tone signal ................................................................................. 15

8.5 Sparse multi-tone complex .................................................................................... 15

8.6 Broadband noise signal ......................................................................................... 16

8.7 Narrow-band noise signal ..................................................................................... 16

8.8 Hann-burst signal .................................................................................................. 16

8.9 Impulsive signal .................................................................................................... 17

9 Acoustical environment .................................................................................................. 17

9.1 General ................................................................................................................. 17

9.2 Free-field conditions ............................................................................................. 17

9.3 Half-space, free-field conditions ............................................................................ 17

9.4 Simulated free-field conditions .............................................................................. 17

9.5 Half-space simulated free-field conditions ............................................................. 17

9.6 Diffuse sound field conditions ............................................................................... 18

9.7 Target application conditions ................................................................................ 18

10 Positioning of the DUT ................................................................................................... 18

10.1 Rated geometrical conditions ................................................................................ 18

10.1.1 General ......................................................................................................... 18

10.1.2 Reference plane and normal vector ............................................................... 18

10.1.3 Reference point ............................................................................................. 18

10.1.4 Reference axis .............................................................................................. 19

10.1.5 Orientation vector .......................................................................................... 19

10.1.6 Evaluation point ............................................................................................. 19

10.1.7 Evaluation distance ....................................................................................... 19

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10.2 Measuring distance between DUT and microphone ............................................... 20

10.2.1 Far-field conditions ........................................................................................ 20

10.2.2 Near-field conditions ...................................................................................... 20

10.2.3 Diffuse field conditions .................................................................................. 20

10.2.4 Target application condition ........................................................................... 21

11 Measurement equipment and test results ....................................................................... 21

12 Accuracy of the acoustical measurement ....................................................................... 21

12.1 General ................................................................................................................. 21

12.2 Measurement uncertainty ...................................................................................... 21

13 Mounting of the DUT ...................................................................................................... 22

13.1 Mounting and acoustic loading of drive units ......................................................... 22

13.2 Mounting and acoustic loading of an electro-acoustic system ................................ 22

14 Preconditioning .............................................................................................................. 23

15 Rated ambient conditions .............................................................................................. 23

15.1 Temperature ranges .............................................................................................. 23

15.1.1 Performance limited temperature range ......................................................... 23

15.1.2 Damage limited temperature range ................................................................ 23

15.2 Humidity ranges .................................................................................................... 23

15.2.1 Relative humidity range ................................................................................. 23

15.2.2 Damage limited humidity range ...................................................................... 23

16 Rated frequency range .................................................................................................. 23

17 Input signal .................................................................................................................... 23

17.1 Rated maximum input value .................................................................................. 23

17.1.1 Condition to be specified ............................................................................... 23

17.1.2 Direct measurement ...................................................................................... 24

17.1.3 Indirect measurement based on SPL ........................................................ 25

max

17.2 Maximum input level ............................................................................................. 25

18 Sound-pressure output .................................................................................................. 26

18.1 Rated maximum sound pressure ........................................................................... 26

18.1.1 Conditions to be specified .............................................................................. 26

18.1.2 Direct measurement ...................................................................................... 26

18.1.3 Indirect measurement based on maximum input value ................................... 27

18.2 Rated maximum sound-pressure level ................................................................... 27

18.3 Short term maximum sound pressure level ............................................................ 27

18.3.1 Conditions to be specified .............................................................................. 27

18.3.2 Method of measurement ................................................................................ 28

18.4 Long term maximum sound pressure level ............................................................ 28

18.4.1 Conditions to be specified .............................................................................. 28

18.4.2 Method of measurement ................................................................................ 29

18.5 Sound pressure in a stated frequency band .......................................................... 29

18.5.1 Condition to be specified ............................................................................... 29

18.5.2 Method of measurement ................................................................................ 29

18.6 Sound-pressure level in a stated frequency band .................................................. 30

18.7 Mean sound-pressure in a stated frequency range ................................................ 30

18.7.1 Condition to be specified ............................................................................... 30

18.7.2 Method of measurement ................................................................................ 30

18.8 Mean sound-pressure level in a stated frequency range ........................................ 30

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19 Frequency response of the fundamental component ...................................................... 30

19.1 Transfer function ................................................................................................... 30

19.1.1 Conditions to be specified .............................................................................. 30

19.1.2 Method of measurements .............................................................................. 30

19.2 SPL frequency response ....................................................................................... 32

19.2.1 Conditions to be specified .............................................................................. 32

19.2.2 Method of measurement ................................................................................ 32

19.3 Time-varying amplitude compression of the fundamental component .................... 33

19.3.1 General ......................................................................................................... 33

19.3.2 Method of measurement ................................................................................ 33

19.4 Amplitude compression at maximum input ............................................................. 33

19.4.1 Short term amplitude compression ................................................................. 33

19.4.2 Method of measurement ................................................................................ 33

19.4.3 Long-term amplitude compression ................................................................. 34

19.4.4 Method of measurement ................................................................................ 34

19.5 Corrections based on a free-field reference measurement .................................... 34

19.5.1 General ......................................................................................................... 34

19.5.2 Correction of the measured sound pressure signal ........................................ 34

19.5.3 Correction of the amplitude response ............................................................ 35

19.6 Effective frequency range ..................................................................................... 36

19.6.1 Conditions to be specified .............................................................................. 36

19.6.2 Method of measurement ................................................................................ 36

19.7 Internal latency ..................................................................................................... 36

19.7.1 Conditions to be specified .............................................................................. 36

19.7.2 Methods of measurement .............................................................................. 36

20 Directional characteristics .............................................................................................. 37

20.1 General ................................................................................................................. 37

20.2 Direct sound field in 3D space .............................................................................. 37

20.2.1 Directional transfer function ........................................................................... 37

20.2.2 Extrapolated far-field data ............................................................................. 37

20.2.3 Parameters of the holographic sound field expansion .................................... 38

20.2.4 Extrapolated near-field data ........................................................................... 39

20.3 Directional far field characteristics ........................................................................ 39

20.3.1 Directional factor ........................................................................................... 39

20.3.2 Directional gain ............................................................................................. 41

20.3.3 Directivity factor............................................................................................. 41

20.3.4 Directivity index ............................................................................................. 41

20.4 Acoustic output power ........................................................................................... 42

20.4.1 Conditions to be specified .............................................................................. 42

20.4.2 Methods of measurement .............................................................................. 42

20.5 Sound power level ................................................................................................ 44

20.6 Mean acoustic output power in a frequency band .................................................. 44

20.6.1 Conditions to be specified .............................................................................. 44

20.6.2 Method of measurement ................................................................................ 44

20.7 Radiation angle ..................................................................................................... 44

20.7.1 Conditions to be specified .............................................................................. 44

20.7.2 Method of measurement ................................................................................ 44

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SIST EN IEC 60268-21:2019
IEC 60268-21:2018  IEC 2018 – 5 –

20.8 Coverage angle or angles ..................................................................................... 45

20.8.1 Conditions to be specified .............................................................................. 45

20.8.2 Method of measurement ................................................................................ 45

20.9 Mean sound pressure level in an acoustical zone .................................................. 45

20.9.1 General ......................................................................................................... 45

20.9.2 Method of measurement ................................................................................ 45

21 Harmonic distortion........................................................................................................ 46

21.1 General ................................................................................................................. 46

21.2 N -order harmonic component ............................................................................. 46

21.2.1 Conditions to be specified .............................................................................. 46

21.2.2 Method of measurement ................................................................................ 46

21.3 Total harmonic components .................................................................................. 47

21.3.1 Conditions to be specified .............................................................................. 47

21.3.2 Method of measurement ................................................................................ 47

21.4 Total harmonic distortion ....................................................................................... 47

21.4.1 Conditions to be specified .............................................................................. 47

21.4.2 Method of measurement ................................................................................ 47

21.5 Higher-order harmonic distortion ........................................................................... 48

21.5.1 Conditions to be specified .............................................................................. 48

21.5.2 Method of measurement ................................................................................ 48

21.6 Maximum sound pressure level limited by total harmonic distortion ....................... 49

21.6.1 Conditions to be specified .............................................................................. 49

21.6.2 Method of measurement ................................................................................ 49

21.7 N -order equivalent input harmonic distortion component .................................... 50

21.7.1 Conditions to be specified .............................................................................. 50

21.7.2 Method of measurement ................................................................................ 50

21.8 Equivalent input total harmonic distortion .............................................................. 51

21.8.1 Conditions to be specified .............................................................................. 51

21.8.2 Method of measurement ................................................................................ 51

22 Two-tone distortion ........................................................................................................ 52

22.1 Variation of excitation frequencies ........................................................................ 52

22.2 Modulation distortion ............................................................................................. 52

22.2.1 Conditions to be specified .............................................................................. 52

22.2.2 Method of measurement ................................................................................ 52

22.3 Amplitude modulation distortion ............................................................................ 53

22.3.1 Conditions to be specified .............................................................................. 53

22.3.2 Method of measurement ................................................................................ 54

23 Multi-tone distortion ....................................................................................................... 54

23.1 Conditions to be specified ..................................................................................... 54

23.2 Method of measurement ....................................................................................... 55

24 Impulsive distortion ........................................................................................................ 55

24.1 Impulsive distortion level ....................................................................................... 55

24.1.1 Conditions to be specified .............................................................................. 55

24.1.2 Method of measurement ................................................................................ 56

24.2 Maximum impulsive distortion ratio ....................................................................... 56

24.2.1 Conditions to be specified .............................................................................. 56

24.2.2 Method of measurement ................................................................................ 56

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