IEC 60268-5:2003+AMD1:2007 CSV

IEC 60268-5
®

Edition 3.1 2007-09
CONSOLIDATED
VERSION
VERSION
CONSOLIDÉE
colour
inside


Sound system equipment –
Part 5: Loudspeakers

Equipements pour systèmes électroacoustiques –
Partie 5: Haut-parleurs

IEC 60268-5:2003+A1:2007

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IEC 60268-5

®


Edition 3.1 2007-09




CONSOLIDATED



VERSION




VERSION



CONSOLIDÉE
colour

inside










Sound system equipment –

Part 5: Loudspeakers




Equipements pour systèmes électroacoustiques –

Partie 5: Haut-parleurs
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

INTERNATIONALE



ICS 33.160.50 ISBN 2-8318-9286-4



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

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 3 ----------------------
IEC 60268-5
®

Edition 3.1 2007-09

REDLINE VERSION
VERSION REDLINE
colour
inside


Sound system equipment –
Part 5: Loudspeakers

Equipements pour systèmes électroacoustiques –
Partie 5: Haut-parleurs

IEC 60268-5:2003+A1:2007

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– 2 – 60268-5  IEC:2003+A1:2007
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Conditions for measurement . 8
3.1 General conditions . 8
3.2 Measuring conditions . 8
4 Test signals . 9
4.1 General . 9
4.2 Sinusoidal signal . 9
4.3 Broadband noise signal . 9
4.4 Narrow-band noise signal . 9
4.5 Impulsive signal . 9
5 Acoustical environment . 9
5.1 General . 9
5.2 Free-field conditions . 9
5.3 Half-space free-field conditions . 10
5.4 Diffuse sound field conditions . 10
5.5 Simulated free-field conditions . 10
5.6 Half-space simulated free-field conditions . 10
6 Unwanted acoustical and electrical noise . 10
7 Positioning of loudspeaker and measuring microphone . 11
7.1 Measuring distance under free-field and half-space free-field conditions . 11
7.2 Positioning of loudspeaker in diffuse field conditions . 11
7.3 Positioning of loudspeaker and microphone in simulated free-field
conditions . 11
8 Measuring equipment . 12
9 Accuracy of the acoustical measurement . 12
10 Mounting of loudspeakers . 12
10.1 Mounting and acoustic loading of drive units . 12
10.2 Mounting and acoustic loading of a loudspeaker system . 12
11 Standard baffle and measuring enclosures . 13
11.1 Standard baffle . 13
11.2 Standard measuring enclosures . 13
12 Preconditioning. 14
13 Type description . 14
13.1 General . 14
13.2 Loudspeaker drive units . 14
13.3 Loudspeaker system . 14
14 Marking of terminals and controls . 14
14.1 General . 14
14.2 Positive terminal . 14
15 Reference plane, reference point and reference axis . 15
15.1 Reference plane – characteristic to be specified . 15
15.2 Reference point – characteristic to be specified . 15
15.3 Reference axis – characteristic to be specified . 15

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60268-5  IEC:2003+A1:2007 – 3 –
16 Impedance and derivative characteristics . 15
16.1 Rated impedance – characteristic to be specified . 15
16.2 Impedance curve . 16
16.3 Total Q-factor (Q ) . 16
t
16.4 Equivalent air volume of a loudspeaker drive unit compliance (V ) . 17
as
17 Input voltage . 18
17.1 Rated noise voltage . 18
17.2 Short-term maximum input voltage . 19
17.3 Long-term maximum input voltage . 20
17.4 Rated sinusoidal voltage . 20
18 Input electrical power . 21
18.1 Rated noise power – characteristic to be specified . 21
18.2 Short-term maximum power – characteristic to be specified . 21
18.3 Long-term maximum power – characteristic to be specified . 21
18.4 Rated sinusoidal power – characteristic to be specified. 21
19 Frequency characteristics . 21
19.1 Rated frequency range – characteristic to be specified . 21
19.2 Resonance frequency . 21
19.3 Tuning frequency of a bass reflex or passive radiator loudspeaker system
– characteristic to be specified . 22
20 Sound pressure under free-field and half-space free-field conditions . 22
20.1 Sound pressure in a stated frequency band . 22
20.2 Sound pressure level in a stated frequency band – characteristic
to be specified . 22
20.3 Characteristic sensitivity in a stated frequency band . 23
20.4 Characteristic sensitivity level in a stated frequency band – characteristic
to be specified . 23
20.5 Mean sound pressure in a stated frequency band . 23
20.6 Mean sound pressure level in a stated frequency band –
characteristic to be specified . 23
21 Response under free-field and half-space free-field conditions . 23
21.1 Frequency response . 23
21.2 Effective frequency range . 24
21.3 Transfer function . 25
22 Output power (acoustic power) . 26
22.1 Acoustic power in a frequency band . 26
22.2 Mean acoustic power in a frequency band . 27
22.3 Efficiency in a frequency band . 27
22.4 Mean efficiency in a frequency band . 27
23 Directional characteristics . 28
23.1 Directional response pattern . 28
23.2 Radiation angle . 28
23.3 Directivity index . 29
23.4 Coverage angle or angles . 30
24 Amplitude non-linearity . 30
24.1 Total harmonic distortion . 30
th
24.2 Harmonic distortion of the n order (where n = 2 or n = 3) . 32
24.3 Characteristic harmonic distortion . 33
th
24.4 Modulation distortion of the n order (where n = 2 or n = 3) . 33

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– 4 – 60268-5  IEC:2003+A1:2007
th
24.5 Characteristic modulation distortion of the n order (where n = 2 or n = 3) . 34
24.6 Difference frequency distortion (of the second order only) . 34
25 Rated ambient conditions . 35
25.1 Temperature ranges . 35
25.2 Humidity ranges . 35
26 Stray magnetic fields . 36
26.1 Static components . 36
26.2 Dynamic components . 36
27 Physical characteristics . 37
27.1 Dimensions . 37
27.2 Mass . 37
27.3 Cable assemblies . 37
28 Design data . 38
29 Indication of the characteristics to be specified . 38

Annex A (informative)  Standard measuring enclosure type A . 44
Annex B (informative)  Standard measuring enclosure type B . 46
Annex C (informative) Definitions of terms used in Clause 13 . 49
Annex D (informative) Listening tests . 51

Bibliography . 52

Figure 1 – Impedance curve of loudspeaker . 17
Figure 2 – Standard baffle, dimensions . 40
Figure 3 – Standard baffle with chamfer . 40
Figure 4 – Standard baffle with sub-baffle . 41
Figure 5 – Standard measuring enclosure type A . 41
Figure 6 – Standard measuring enclosure type B . 42
Figure 7 – Block diagram of test set-up . 42
Figure 8 – Measuring apparatus for stray magnetic field . 43
Figure A.1 – An example of standard measuring enclosure type A . 44
Figure A.2 – The correction curve for the diffraction effect of the standard measuring
enclosure from free-field to half-space free-field  . 45
Figure A.3 – The correction curve for the diffraction effect of a standard measuring
enclosure from free-field to half-space free-field . 45
Figure B.1 – An example of standard measuring enclosure type B . 46
Figure B.2 – Construction of scalable measuring enclosure type B . 47
Figure B.3 – The correction curve for the diffraction effect of the standard measuring
enclosure from free-field to half-space free-field . 48
Figure B.4 – The correction curve for the diffraction effect of the standard measuring
enclosure from free-field to half-space free-field . 48

Table 1 – Indication of the characteristics to be specified . 39
Table B.1 – Dimensions and ratios of scalable measuring enclosure type B . 47

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60268-5  IEC:2003+A1:2007 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SOUND SYSTEM EQUIPMENT –

Part 5: Loudspeakers


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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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.

This Consolidated version of IEC 60268-5 bears the edition number 3.1. It consists of
the third edition (2003) [documents 100/648/FDIS and 100/674/RVD] and its amendment
1 (2007) [documents 100/1189/CDV and 100/1245/RVC]. The technical content is
identical to the base edition and its amendment.
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions and deletions are displayed in red, with
deletions being struck through. A separate Final version with all changes accepted is
available in this publication.
This publication has been prepared for user convenience.

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– 6 – 60268-5  IEC:2003+A1:2007
International Standard IEC 60268-5 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The bilingual version (2013-08) of this standard corresponds to the monolingual English
version, published in 2007-09.
This standard is to be read in conjunction with IEC 60268-1, IEC 60268-2 and ISO 3741.
The French versions of this standard and its amendment 1 have not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of the base publication and its amendments will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

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 document using a
colour printer.

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60268-5  IEC:2003+A1:2007 – 7 –
SOUND SYSTEM EQUIPMENT –

Part 5: Loudspeakers



1 Scope
This standard applies to sound system loudspeakers, treated entirely as passive elements.
Loudspeakers with built-in amplifiers are excluded.
NOTE 1 The term “loudspeaker” used in this standard relates to loudspeaker drive units themselves and also to
loudspeaker systems, which comprise one or more loudspeaker drive units provided with a baffle, enclosure or
horn and such relevant devices as built-in crossover filters, transformers and any other passive element.
The purpose of this standard is to give the characteristics to be specified and the relevant
methods of measurement for loudspeakers using sinusoidal or specified noise or impulsive
signals.
NOTE 2 The methods of measurement given in this standard have been chosen for their appropriateness to the
characteristics.
NOTE 3 If equivalent results can be obtained using other methods of measurement, details of the methods used
should be presented with the results.
NOTE 4 The following items are under consideration:
– loudspeakers with built-in amplifiers;
– measurements under conditions other than free-field, half-space free-field and diffuse field;
– measurements with signals other than sinusoidal or noise or impulsive signals.
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 60050(151), International Electrotechnical Vocabulary (IEV) – Part 151: Electrical and
magnetic devices
IEC 60263, Scales and sizes for plotting frequency characteristics and polar diagrams
IEC 60268-1, Sound system equipment – Part 1: General
IEC 60268-2, Sound system equipment – Part 2: Explanation of general terms and calculation
methods
IEC 60268-3, Sound system equipment – Part 3: Amplifiers
IEC 60268-11, Sound system equipment – Part 11: Application of connectors for the
interconnection of sound system components
IEC 60268-12, Sound system equipment – Part 12: Application of connectors for broadcast
and similar use
IEC 60268-14, Part 14: Circular and elliptical loudspeakers; outer frame diameters and
mounting dimensions
IEC 60651, Sound level meters

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– 8 – 60268-5  IEC:2003+A1:2007
IEC 61260, Electroacoustics – Octave-band and fractional-octave-band filters
ISO 3741, Acoustics – Determination of sound power levels of noise sources using sound
pressure – Precision methods for reverberation rooms
ISO 3744, Acoustics – Determination of sound power levels of noise sources using sound
pressure – Engineering method in an essentially free field over a reflecting plane
ISO 3745, Acoustics – Determination of sound power levels of noise sources – Precision
methods for anechoic and semi-anechoic rooms
3 Conditions for measurement
3.1 General conditions
This standard is to be used in conjunction with IEC 60268-1, IEC 60268-2 and ISO 3741.
3.2 Measuring conditions
3.2.1 General
For convenience in specifying how loudspeakers are to be set up for measurement, normal
measuring conditions are defined in this standard. To obtain the
...