IEC 62458:2010

Sound system equipment - Electroacoustical transducers - Measurement of large signal parameters

IEC 62458:2010 applies to transducers such as loudspeaker drive units, loudspeaker systems, headphones, micro-speakers, shakers and other actuators using either an electro-dynamical or electro-magnetic motor coupled with a mechanical suspension. The large signal behaviour of the transducer is modelled by a lumped parameter model considering dominant nonlinearities such as force factor, stiffness and inductance. It defines the basic terms and parameters of the model, the methods of measurements and the way the results should be reported. It cancels and replaces IEC/PAS 62458 published in 2006. It constitutes a technical revision. The main changes are:
- descriptions of the methods of measurement are adjusted to the state of the technology;
- addition of Clauses 4 to 15;
- integration of Annex A in the main body of the standard;
- overall textual review.

Équipements pour systèmes électroacoustiques - Transducteurs électroacoustiques - Mesurage des paramètres de signaux forts

L'IEC 62458:2010 s'applique aux transducteurs tels que les unités motrices de haut-parleurs, les systèmes de haut-parleurs, les casques, les micro-haut-parleurs, les vibrateurs et autres actionneurs qui utilisent un moteur électrodynamique ou électromagnétique couplé à une suspension mécanique. Le comportement des signaux forts du transducteur est modélisé par un modèle de paramètres localisés qui tient compte des non-linéarités dominantes telles que le facteur de force, la rigidité et l'inductance, comme cela est représenté à la Figure 1. Cette norme définit les termes et paramètres de base du modèle, ainsi que les méthodes de mesurage et la manière dont il convient de consigner les résultats.
L'IEC 62458:2010 annule et remplace l'IEC/PAS 62458 parue en 2006. Elle constitue une révision technique. Les principales modifications sont les suivantes:
- la description des méthodes de mesurage a été adaptée à l'état de la technologie;
- les Articles 4 à 15 ont été ajoutés;
- l'Annexe A a été intégrée au corps de la norme;
- le texte a été revu dans son intégralité.

General Information

• Status: Published
• Publication Date: 26-Jan-2010
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 33.160.50 - Accessories
• Technical Committee: TA 20 - Analogue and digital audio
• Current Stage: PPUB - Publication issued
• Start Date: 31-Jan-2010
• Completion Date: 27-Jan-2010

Relations

• Replaces: IEC PAS 62458:2006 - Sound system equipment - Electroacoustical transducers - Measurement of large signal parameters
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62458 ®
Edition 1.0 2010-01
INTERNATIONAL
STANDARD
colour
inside
Sound system equipment – Electroacoustical transducers – Measurement of
large signal parameters
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.
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please contact the address below or your local IEC member National Committee for further information.

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IEC 62458 ®
Edition 1.0 2010-01
INTERNATIONAL
STANDARD
colour
inside
Sound system equipment – Electroacoustical transducers – Measurement of
large signal parameters
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
T
ICS 33.160.50 ISBN 978-2-88910-733-9
– 2 – 62458 © IEC:2010(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Terms and definitions .7
4 Test signals.9
4.1 General .9
4.2 Large d.c. signal.9
4.3 Large d.c. signal and small a.c. signal.9
4.4 Broadband noise signal .9
4.5 Music .9
5 Mounting condition .10
5.1 Drive units.10
5.2 Loudspeaker systems.10
6 Climatic conditions .10
7 Acoustical environment .10
8 Preconditioning .10
9 Time-varying properties of the loudspeaker .11
10 Methods of measurement .11
10.1 General .11
10.2 Static or quasi-static method .11
10.3 Point-by-point dynamic method .12
10.4 Full dynamic method .14
11 Nonlinear force factor .15
11.1 Force factor curve Bl(x) .15
11.2 Force-factor limited displacement, X .16
Bl
11.3 Symmetry point, x (x ).17
sym ac
11.4 Voice coil offset, x .18
offset
12 Nonlinear stiffness.18
12.1 Nonlinear stiffness curve K (x) .18
ms
12.2 Compliance-limited displacement x .19
C
12.3 Stiffness asymmetry A (x ).19
peak
K
13 Displacement-dependent inductance, L (x).20
e
13.1 Inductance curve L (x) .20
e
13.2 Inductance-limited displacement, x .21
L
14 Current -dependent inductance, L (i).21
e
14.1 Characteristic to be specified .21
14.2 Method of measurement .21
15 Parameters derived from geometry and performance.22
15.1 Maximal peak displacement, x .22
MAXd
15.2 Method of measurement .22
Bibliography.23

Figure 1 – Electro-dynamical transducer .7

62458 © IEC:2010(E) – 3 –
Figure 2 –Static and quasi-static measurement setup .12
Figure 3 – Setup for measurement of large signal parameters by using the point-by-
point dynamic method.13
Figure 4 – Setup for dynamic measurement of large signal parameters.14
Figure 5 – Reading the maximal peak displacement x limited by force factor only .16
B
Figure 6 – Reading the voice coil offset from the symmetry point x (x ) curve.17
sym ac
Figure 7 – Definition of the symmetry point x in the nonlinear force factor
sym
characteristic Bl(x) .18
Figure 8 – Reading the stiffness asymmetry from the K (x) curve .20
ms
– 4 – 62458 © IEC:2010(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SOUND SYSTEM EQUIPMENT –
ELECTROACOUSTICAL TRANSDUCERS –
MEASUREMENT OF LARGE SIGNAL PARAMETERS

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
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
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assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
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6) All users should ensure that they have the latest edition of this publication.
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62458 has been prepared by IEC technical committee 100: Audio,
video and multimedia systems and equipment.
This first edition cancels and replaces IEC/PAS 62458 published in 2006. It constitutes a
technical revision. The main changes are listed below:
– descriptions of the methods of measurement are adjusted to the state of the technology;
– addition of Clauses 4 to 15;
– integration of Annex A in the main body of the standard;
– overall textual review.
62458 © IEC:2010(E) – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
100/1624/FDIS 100/1647/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.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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 version of this publication may be issued at a later date.

IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

– 6 – 62458 © IEC:2010(E)
INTRODUCTION
Electro-mechanical-acoustical transducers such as loudspeaker drive units, loudspeaker
systems, headphones, micro-speakers, shakers, and other actuators behave in a nonlinear
manner at higher amplitudes. This limits the acoustical output and generates nonlinear signal
distortion. Linear models fail in describing the large signal behaviour of such transducers and
extended models have been developed which consider dominant nonlinearities in the motor
and suspens
...

IEC 62458 ®
Edition 1.0 2010-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Sound system equipment – Electroacoustical transducers – Measurement of
large signal parameters
Équipements pour systèmes électroacoustiques – Transducteurs
électroacoustiques – Mesurage des paramètres de signaux forts

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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IEC 62458 ®
Edition 1.0 2010-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Sound system equipment – Electroacoustical transducers – Measurement of

large signal parameters
Équipements pour systèmes électroacoustiques – Transducteurs

électroacoustiques – Mesurage des paramètres de signaux forts

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.160.50 ISBN 978-2-8322-1080-3

– 2 – IEC 62458:2010  IEC 2010
CONTENTS
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Test signals . 9
4.1 General . 9
4.2 Large d.c. signal . 9
4.3 Large d.c. signal and small a.c. signal . 9
4.4 Broadband noise signal . 9
4.5 Music . 9
5 Mounting condition . 10
5.1 Drive units . 10
5.2 Loudspeaker systems . 10
6 Climatic conditions . 10
7 Acoustical environment . 10
8 Preconditioning . 10
9 Time-varying properties of the loudspeaker . 11
10 Methods of measurement . 11
10.1 General . 11
10.2 Static or quasi-static method . 11
10.3 Point-by-point dynamic method . 12
10.4 Full dynamic method . 14
11 Nonlinear force factor . 15
11.1 Force factor curve Bl(x) . 15
11.2 Force-factor limited displacement, X . 16
Bl
11.3 Symmetry point, x (x ) . 17
sym ac
11.4 Voice coil offset, x . 18
offset
12 Nonlinear stiffness . 18
12.1 Nonlinear stiffness curve K (x) . 18
ms
12.2 Compliance-limited displacement xC . 19
12.3 Stiffness asymmetry A (x ) . 19
K peak
13 Displacement-dependent inductance, L (x) . 20
e
13.1 Inductance curve L (x) . 20
e
13.2 Inductance-limited displacement, x . 21
L
14 Current -dependent inductance, L (i) . 21
e
14.1 Characteristic to be specified . 21
14.2 Method of measurement . 21
15 Parameters derived from geometry and performance . 22
15.1 Maximal peak displacement, x . 22
MAXd
15.2 Method of measurement . 22

Figure 1 – Electro-dynamical transducer . 7
Figure 2 –Static and quasi-static measurement setup . 12
Figure 3 – Setup for measurement of large signal parameters by using the point-by-
point dynamic method . 13
Figure 4 – Setup for dynamic measurement of large signal parameters . 14

Figure 5 – Reading the maximal peak displacement x limited by force factor only . 16
B
Figure 6 – Reading the voice coil offset from the symmetry point x (x ) curve . 17
sym ac
Figure 7 – Definition of the symmetry point x in the nonlinear force factor
sym
characteristic Bl(x) . 18
Figure 8 – Reading the stiffness asymmetry from the K (x) curve. 20
ms
– 4 – IEC 62458:2010  IEC 2010
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SOUND SYSTEM EQUIPMENT –
ELECTROACOUSTICAL TRANSDUCERS –
MEASUREMENT OF LARGE SIGNAL PARAMETERS

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 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 commit
...