EN 54-24:2008

SLOVENSKI STANDARD
01-julij-2008
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Fire detection and fire alarm systems - Part 24: Components of voice alarm systems -
Loudspeakers
Brandmeldeanlagen - Teil 24: Komponenten für Sprachalarmierungssysteme -
Lautsprecher
Systemes de détection et d'alarme incendie - Composants des systemes d'alarme
vocale - Partie 24 : Haut-parleurs
Ta slovenski standard je istoveten z: EN 54-24:2008
ICS:
13.220.20 3RåDUQD]DãþLWD Fire protection
13.320 Alarmni in opozorilni sistemi Alarm and warning systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 54-24
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2008
ICS 13.310
English Version
Fire detection and fire alarm systems - Part 24: Components of
voice alarm systems - Loudspeakers
Systèmes de détection et d'alarme incendie - Composants Brandmeldeanlagen - Teil 24: Komponenten für
des systèmes d'alarme vocale - Partie 24 : Haut-parleurs Sprachalarmierungssysteme - Lautsprecher
This European Standard was approved by CEN on 23 February 2008.
CEN 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 Management Centre or to any CEN 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 CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 54-24:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.4
Introduction .6
1 Scope .7
2 Normative references .7
3 Terms, definitions and abbreviations.8
3.1 Terms and definitions .8
3.2 Abbreviations.11
4 Requirements.11
4.1 Compliance.11
4.2 Frequency response limits .11
4.3 Durability .12
4.4 Construction.12
4.4.1 Provision for external conductors .12
4.4.2 Materials .12
4.4.3 Enclosure protection.12
4.4.4 Access .12
4.5 Marking and data .12
4.5.1 Marking .12
4.5.2 Information in the product data sheet .13
5 Tests.14
5.1 General.14
5.1.1 Atmospheric conditions for tests .14
5.1.2 Operating conditions for tests .14
5.1.3 Mounting arrangements.14
5.1.4 Tolerances .14
5.1.5 Frequency response measurement and sensitivity calculation .14
5.1.6 Frequency response measurement and sensitivity calculation for loudspeakers requiring
dedicated system equalization.16
5.1.7 Provision for tests .16
5.1.8 Test schedule.16
5.2 Reproducibility.18
5.2.1 Object of the test.18
5.2.2 Test procedure.18
5.2.3 Test requirements.18
5.3 Rated impedance .18
5.3.1 Object of the test.18
5.3.2 Test procedure.18
5.3.3 Test requirements.19
5.4 Horizontal and vertical coverage angles.19
5.4.1 Object of the test.19
5.4.2 Test procedure.19
5.4.3 Test requirement.20
5.5 Maximum sound pressure level .20
5.5.1 Object of the test.20
5.5.2 Test procedure.20
5.5.3 Test requirements.20
5.6 Rated noise power (durability) .21
5.6.1 Object of the test.21
5.6.2 Test procedure.21
5.6.3 Test requirement: .21
5.7 Dry heat (operational) .21
5.7.1 Object of the test .21
5.7.2 Test procedure.22
5.7.3 Test requirements .22
5.8 Dry heat (endurance).22
5.8.1 Object of the test .22
5.8.2 Test procedure.23
5.8.3 Test requirements .23
5.9 Cold (operational).23
5.9.1 Object of the test .23
5.9.2 Test procedure.24
5.9.3 Test requirements .24
5.10 Damp heat, cyclic (operational) .25
5.10.1 Object of the test .25
5.10.2 Test procedure.25
5.10.3 Test requirements .25
5.11 Damp heat, steady state (endurance).26
5.11.1 Object of the test .26
5.11.2 Test procedure.26
5.11.3 Test requirements .26
5.12 Damp heat, cyclic (endurance) .27
5.12.1 Object of the test .27
5.12.2 Test procedure.27
5.12.3 Test requirements .27
5.13 Sulfur dioxide (SO ) corrosion (endurance) .28
5.13.1 Object of the test .28
5.13.2 Test procedure.28
5.13.3 Test requirements .28
5.14 Shock (operational) .29
5.14.1 Object of the test .29
5.14.2 Test procedure.29
5.14.3 Test requirements .29
5.15 Impact (operational) .30
5.15.1 Object of the test .30
5.15.2 Test procedure.30
5.15.3 Test requirements .30
5.16 Vibration, sinusoidal (operational) .31
5.16.1 Object of the test .31
5.16.2 Test procedure.31
5.16.3 Test requirements .32
5.17 Vibration, sinusoidal (endurance) .32
5.17.1 Object of the test .32
5.17.2 Test procedure.32
5.17.3 Test requirements .33
5.18 Enclosure protection.33
5.18.1 Object of the tests .33
5.18.2 Enclosure of the loudspeaker .33
5.18.3 Test procedures.33
5.18.4 Test requirements .34
Annex A (normative) Acoustical measurements.35
Annex B (normative) Measuring rated noise power (durability).41
Annex C (informative) Loudspeaker references.48
Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU
Construction Products Directive (89/106/EEC) .50

Foreword
This document (EN 54-24:2008) has been prepared by Technical Committee CEN/TC 72 “Fire detection and
fire alarm systems”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by October 2008, and conflicting national standards shall be withdrawn at
the latest by April 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.
EN 54 Fire detection and fire alarm systems consists of the following parts:
 Part 1: Introduction
 Part 2: Control and indicating equipment
 Part 3: Fire alarm devices – Sounders
 Part 4: Power supply equipment
 Part 5: Heat detectors – Point detectors
 Part 7: Smoke detectors – Point detectors using scattered light, transmitted light or ionization
 Part 10: Flame detectors – Point detectors
 Part 11: Manual call points
 Part 12: Smoke detectors – Line detectors using an optical light beam
 Part 13: Compatibility assessment of system components
 Part 14: Guidelines for planning, design, installation, commissioning, use and maintenance
 Part 15: Point detectors using a combination of detected phenomena
 Part 16: Voice alarm control and indicating equipment
 Part 17: Short-circuit isolators
 Part 18: Input/output devices
 Part 20: Aspirating smoke detectors
 Part 21: Alarm transmission and fault warning routine equipment
 Part 22: Resettable line-type heat detectors
 Part 23: Fire alarm devices – Visual alarms
 Part 24: Components of voice alarm systems – Loudspeakers
 Part 25: Components using radio links
1)
 Part 26: Point fire detectors using carbon monoxide sensors
1)
 Part 27: Duct smoke detectors
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

1) Under preparation.
Introduction
The purpose of a voice alarm loudspeaker as a component of a voice alarm system is to provide intelligible
warning to person(s) within, or in the vicinity of, a building in which a fire emergency has occurred and to
enable such person(s) to take appropriate measures against a pre-determined evacuation plan.
The primary reason for using a voice alarm system instead of the coded warnings given by sounders is to
reduce the time taken for those at risk to recognize that an emergency exists, and to give clear instructions on
what to do next. This means that voice alarm loudspeakers need to achieve a minimum acoustical
performance, as well as constructional and environmental requirements, to be suitable for use in fire detection
and fire alarm systems.
This standard recognizes that the exact nature of the acoustical requirements for voice alarm loudspeakers
will vary according to the nature of the space into which there are installed. It therefore specifies the minimum
requirements that apply to voice alarm loudspeakers and a common method for testing their operational
performance against parameters specified by the manufacturers.
This European Standard gives common requirements for the construction and robustness of voice alarm
loudspeakers as well as their performance under climatic and mechanical conditions which are likely to occur
in the service environment. As the types of loudspeaker considered in this European Standard are passive
electromechanical devices not involving sensitive electronic circuits, electromagnetic compatibility (EMC) tests
have not been included. The loudspeakers have been classified in either an indoor or an outdoor application
environment category.
This European Standard requires that manufacturers specify certain characteristics in a consistent manner so
that designers can make objective decisions about which loudspeaker to use in specific applications.
1 Scope
This European Standard specifies requirements, test methods and performance criteria for loudspeakers
intended to broadcast a warning of fire between a fire detection and fire alarm system and the occupants of a
building.
This European Standard specifies loudspeakers for two types of application environment: type A, generally for
indoor use and type B, generally for outdoor use.
This European Standard does not cover loudspeakers for special applications, for example loudspeaker for
use in hazardous applications, if such applications require additional or other requirements or tests than those
given in this European Standard.
This European Standard is not intended to cover addressable loudspeakers, loudspeakers with active
components.
Voice alarm sounders are covered in EN 54-3:2001.
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.
EN 54-1:1996, Fire detection and fire alarm systems — Part 1: Introduction
EN 54-3:2001, Fire detection and fire alarm systems — Part 3: Fire alarm devices — Sounders
EN 60068-1:1994, Environmental testing — Part 1: General and guidance (IEC 60068-1:1988 + Corrigendum
1988 + A1:1992)
EN 60068-2-1:2007, Environmental testing — Part 2-1: Tests — Test A: Cold (IEC 60068-2-1:2007)
EN 60068-2-2:1993, Basic environmental testing procedures — Part 2-2: Tests — Tests B — Dry heat
(IEC 60068-2-2:1974 + IEC 60068-2-2 A:1976)
EN 60068-2-2:1993/A1:1993, Basic environmental testing procedures — Part 2-2: Tests — Tests B — Dry
heat – (IEC 60068-2-2:1974/A1:1993)
EN 60068-2-2:1993/A2:1994, Basic environmental testing procedures — Part 2-2: Tests — Tests B — Dry
heat – (IEC 60068-2-2:1974/A2:1994)
EN 60068-2-6:1995, Environmental testing — Part 2-6: Tests — Test Fc: Vibration (sinusoidal)
(IEC 60068-2-6:1995 + Corrigendum 1995)
EN 60068-2-27:1993, Basic environmental testing procedures — Part 2: Tests — Test Ea and guidance:
Shock (IEC 60068-2-27:1987)
EN 60068-2-30:2005, Environmental testing — Part 2-30: Tests — Test Db: Damp heat, cyclic (12 h + 12 h
cycle) (IEC 60068-2-30:2005)
EN 60068-2-42:2003, Environmental testing — Part 2-42: Tests — Test Kc: Sulphur dioxide test for contacts
and connections (IEC 60068-2-42:2003)
EN 60068-2-75:1997, Environmental testing — Part 2-75: Tests — Test Eh: Hammer (IEC 60068-2-75:1997)
EN 60068-2-78:2001, Environmental testing — Part 2-78: Tests — Test Cab: Damp heat, steady state
(IEC 60068-2-78:2001)
EN 60529:1991, Degrees of protection provided by enclosures (IP code) (IEC 60529:1989)
EN 60529:1991/A1:2000, Degrees of protection provided by enclosures (IP code) — Amendment A1
(IEC 60529:1989/A1:1999)
EN 60695-11-10:1999, Fire hazard testing — Part 11-10: Test flames — 50 W horizontal and vertical flame
test methods (IEC 60695-11-10:1999)
EN 60695-11-10:1999/A1:2003, Fire hazard testing – Part 11-10: Test flames — 50 W horizontal and vertical
flame test methods – Amendment A1 (IEC 60695- 11-10:1999/A1:2003
EN 60695-11-20:1999, Fire hazard testing — Part 11-20: Test flames — 500 W flame test methods
(IEC 60695-11-20:1999)
EN 60695-11-20:1999/A1:2003, Fire hazard testing — Part 11-20: Test flames — 500 W flame test methods)
— Amendment A1 (IEC 60695-11- 20:1999/A1:2003)
EN 61260:1995, Electroacoustics — Octave-band and fractional-octave-band filters (IEC 61260:1995)
EN 61672-1:2003, Electroacoustics — Sound level meters — Part 1: Specifications (IEC 61672-1:2002)
EN ISO 9001:2000, Quality management systems — Requirements (ISO 9001:2000)
IEC 60268-1:1985, Sound system equipment — Part 1: General
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 54-1:1996 and the following apply.
3.1.1
1/3 octave
frequency band as defined in EN 61260
3.1.2
coverage angle
smallest angle between two directions on either side of the reference axis at which the sound pressure level is
6 dB less than the sound pressure level on the reference axis
NOTE This angle is measured in the vertical and horizontal planes.
3.1.3
free-field condition
acoustical environment in which the sound pressure decreases with the distance (r) from a point source
according to a 1/r law, with an accuracy of ± 10 %, in the region that will be occupied by the sound field
between the loudspeaker system and the microphone during the measurements
EXAMPLE An anechoic room, a quiet outdoor space.
3.1.4
frequency response
sound pressure level at a distance of 4 m from the reference point on the reference axis, produced at 1/3
octave frequency bands, from 100 Hz to 10 kHz (centre frequencies)
NOTE This is also referred to as magnitude or amplitude response.
3.1.5
ground plane measurement
measurement under half-space free-field conditions used to simulate a free-field condition in which the
loudspeaker is mounted above an acoustically totally reflective boundary surface and aimed so that its
reference axis is points towards a measurement microphone that is placed directly on the boundary surface
NOTE In order to achieve measurement results that are comparable with a free-field condition, ground-plane
measurements need to be corrected by -6 dB at all frequencies.
3.1.6
half-space free-field condition
acoustical environment that is confined by a plane of sufficient size and in which the free-field exists in a
hemisphere, so that the sound pressure from a point source mounted in the surface of that plane decreases in
the manner defined in 3.1.3
EXAMPLE A half-space anechoic room.
3.1.7
horizontal plane
virtual plane of the loudspeaker containing the reference axis, as specified by the manufacturer
NOTE There may be several horizontal planes corresponding to several reference axes.
EXAMPLE See Annex C.
3.1.8
maximum sound pressure level
total sound pressure level at 4 m from the reference point on the reference axis of a loudspeaker supplied with
a simulated programme signal at the rated noise power
NOTE For simulated programme signal see 3.1.19.
3.1.9
measuring distance
distance between the reference point (see 3.1.17) and the measuring microphone
3.1.10
loudspeaker
transducer which converts electrical energy into acoustical energy, comprising one or more drive units, one or
more enclosures, a cable termination block, and relevant devices such as filters, transformers and any
passive element
NOTE Some loudspeakers are a combination of one or more loudspeaker housing(s) and a termination box
interconnected by a cable. The loudspeaker housing(s), cable(s) and terminal box should be considered to be ‘the
loudspeaker’ for the purposes of this European Standard. Examples of such loudspeakers include: pendant types and
loudspeakers with mechanically adjustable orientation such as horn or column loudspeakers and loudspeaker arrays.
3.1.11
pink noise
random noise signal with a spectral density that decreases by 3 dB per octave, giving constant energy per
octave
3.1.12
rated impedance
value of pure resistance, stated by the manufacturer that is to be substituted for the loudspeaker when defining
the required power of the source
3.1.13
rated noise power
electrical power calculated from the equation U ²/R, where U is the rated noise voltage and R is the rated
n n
impedance
NOTE 1 For transformer-coupled loudspeakers, the rated noise power is the highest power setting specified by the
manufacturer.
NOTE 2 The rated noise power is also called power-handling capacity.
3.1.14
rated noise voltage
RMS voltage, as specified by the manufacturer, of the simulated programme signal that the loudspeaker can
handle without thermal or mechanical damage
NOTE 1 See Annex B.
NOTE 2 For transformer-coupled loudspeakers, the rated noise voltage typically equals 50 V, 70 V or 100 V.
3.1.15
reference axis
virtual axis of the loudspeaker as specified by the manufacturer
NOTE There can be several reference axis.
EXAMPLE See Annex C.
3.1.16
reference plane
virtual plane perpendicular to the reference axis, as specified by the manufacturer
EXAMPLE See Annex C.
3.1.17
reference point
point at the intersection of the reference plane and the reference axis
EXAMPLE See Annex C.
3.1.18
sensitivity
sound pressure level S of a loudspeaker supplied with a 1 W pink noise signal from 100 Hz up to 10 kHz
measured at a distance of 4 m from the reference point on the reference axis
3.1.19
simulated programme signal
signal, whose mean power spectral density closely resembles the average of the mean power spectral
densities of a wide range of audio signals
EXAMPLE See Annex B.
3.1.20
type A loudspeaker
loudspeaker that is primarily intended for indoor applications
NOTE Type A loudspeakers can be suitable for some protected outdoor situations.
3.1.21
type B loudspeaker
loudspeaker that is primarily intended for outdoor applications
NOTE Type B loudspeakers can be more suitable than type A for some indoor situations where high temperature
and/or humidity are present.
3.1.22
vertical plane
virtual plane of the loudspeaker perpendicular to the horizontal plane and containing the reference axis
EXAMPLE See Annex C.
3.2 Abbreviations
DC Direct current
RMS Root mean square
4 Requirements
4.1 Compliance
In order to conform to this European Standard, voice alarm loudspeakers shall meet the requirements of this
clause, which shall be verified by visual inspection or engineering assessment, shall be tested as described in
Clause 5 and shall meet the requirements of the tests.
4.2 Frequency response limits
The loudspeaker frequency response shall fit within the un-shaded area shown in Figure 1.
NOTE If the frequency response shown in Figure 1 can only be achieved by means of a frequency equalizer that is
specified by the manufacturer for normal use (see 4.5.2 b)), it is acceptable to insert a dedicated equalizer in the
measurement setup (see 5.1.6).

Key
1 relative level [dB]
2 1/3 octave band centre frequency [Hz]
Figure 1 — Frequency response limit
4.3 Durability
The voice alarm loudspeaker shall be rated for at least 100 h operation at the rated noise power specified by
the manufacturer (refer to the test procedure described in 5.6).
4.4 Construction
4.4.1 Provision for external conductors
The loudspeaker shall provide space within its enclosure for external conductors to be brought in and
terminated. Entry holes for conductors or cables shall be provided or the location where such holes are to be
made shall be indicated, by providing a template or some other suitable means.
Terminals for connecting external conductors shall be designed so that they are clamped between metal
surfaces without being damaged. Each terminal shall enable the connection of any conductor having a cross-
2 2
sectional area between 0,8 mm and 2,5 mm .
4.4.2 Materials
The loudspeaker shall be constructed of material(s) capable of withstanding the tests specified in Clause 5. In
addition, the material(s) of plastic enclosures shall conform to the following flammability requirements:
a) EN 60695-11-10:1999 as amended by EN 60695-11-10:1999/A1:2003 Class V-2 or HB75 for devices
operating from a voltage source less than or equal to 30 V RMS or 42,4 V DC and consuming less than
15 W of power;
b) EN 60695-11-20:1999 as amended by EN 60695-11-20:1999/A1:2003 Class 5VB for devices operating
from a voltage source greater than 30 V RMS or 42,4 V DC and consuming more than 15 W of power.
4.4.3 Enclosure protection
The degree of protection provided by the enclosure of fire alarm loudspeakers shall conform to the following
requirements:
 for type A, indoor applications: Code IP21C of EN 60529:1991 as amended by EN 60529:1991/A1:2000;
 for type B, outdoor applications: Code IP33C of EN 60529:1991 as amended by EN 60529:1991/A1:2000.
4.4.4 Access
Means shall be provided to limit access for removal of parts of or the whole device and to make adjustment to
the mode of operation, e.g. special tool, codes, hidden screws, seals.
4.5 Marking and data
4.5.1 Marking
Each voice alarm loudspeaker shall be clearly marked with the following information:
a) number of this European Standard (i.e. EN 54-24);
b) environmental type, i.e. type A or type B;
c) name or trademark of the manufacturer or supplier;
d) manufacturer or supplier model designation (type or number);
e) terminal designations;
f) rated noise voltage for transformer-coupled loudspeakers;
g) rated impedance for direct-coupled loudspeakers;
h) rated noise power (at the highest power setting);
i) power settings (e.g. transformer tapping options for transformer-coupled loudspeakers);
j) mark(s) or code(s) (for example, a serial number or batch code), by which the manufacturer can identify,
at least, the date or batch and place of manufacture.
Where any marking on the device uses symbols or abbreviations not in common use then these shall be
explained in the data supplied with the device.
The marking need not be discernible when the device is installed and ready for use but shall be visible during
installation and shall be accessible during maintenance. The markings shall not be placed on screws or other
easily removable parts.
4.5.2 Information in the product data sheet
The information required in 4.5.1 together with the following shall be supplied with the device, or shall be given
in a data sheet or technical manual identified on, or with each device:
a) frequency response for each stated reference axis;
b) sensitivity for the stated reference axis (see 5.1.5);
c) horizontal and vertical coverage angles at 500 Hz, 1 kHz, 2 kHz, 4 kHz for each stated reference plane,
measured as described in 5.4.2;
d) maximum sound pressure level (at highest power setting) for each stated reference plane, measured as
described in 5.5.2;
e) reference axis, reference plane and horizontal plane;
f) rated noise power, measured as described in 5.6.2;
g) rated impedance for each tapping, measured as described in 5.3.2;
h) 1/3 octave band frequency response of any dedicated active equalization which may be required;
i) any other information necessary to enable correct installation, operation and maintenance of the device;
j) acoustical measurement environment used for the specifications listed in this data sheet, e.g. free-field,
half-space free-field, standard baffle.
If different settings, except power settings, are available on the loudspeaker, such as tone control or
adjustable parts, the manufacturer shall specify, for each of the above, the applicable configuration(s).
5 Tests
5.1 General
5.1.1 Atmospheric conditions for tests
Unless otherwise stated in a test procedure, the testing shall be carried out after the test specimen has been
allowed to stabilize in the standard atmospheric conditions for testing described in EN 60068-1, as follows:
 temperature: 15 ºC to 35 ºC;
 relative humidity: 25 % to 75 %;
 air pressure: 86 kPa to 106 kPa.
The temperature and humidity shall be substantially constant for each test where these standard atmospheric
conditions are applied.
5.1.2 Operating conditions for tests
Unless otherwise stated in a test procedure the test specimen shall be:
a) set at its highest power setting;
b) preconditioned in accordance with Annex A;
c) mounted in the acoustical environment as described in Annex A and as specified by the manufacturer
(see 4.5.2 j)).
If different settings, except power settings, are available on the loudspeaker, such as tone control or adjustable
parts (excluding external mounting bracket), the manufacturer shall specify the configuration(s) to be tested.
5.1.3 Mounting arrangements
For environmental conditioning tests, unless otherwise specified, the specimen shall be mounted by its normal
means of attachment in accordance with the manufacturer's instructions. If these instructions describe more
than one method of mounting then the method considered to be most unfavourable shall be chosen for each
test.
NOTE For some loudspeakers, due to their size, it might not be practical to conduct all of the environmental tests. In
such cases, testing may be carried out on a smaller representative specimen, where this is deemed to produce a valid
result for a given test.
5.1.4 Tolerances
The tolerances for the environmental test parameters shall be as given in the basic reference standards for
the test (e.g. the relevant part of EN 60068).
If a specific tolerance or deviation limit is not specified in a requirement or test procedure, then a deviation
limit of ± 5 % shall be applied.
5.1.5 Frequency response measurement and sensitivity calculation
5.1.5.1 Measuring arrangement
Measurements shall be made in accordance with Annex A.
5.1.5.2 Basic measurements
The sound pressure level L shall be measured in the 1/3 octave bands from 100 Hz to 10 kHz, at the
m,i
measuring distance, on the reference axis, when the loudspeaker is supplied with a band-filtered noise signal of
constant voltage.
These levels L shall be the average true RMS values over a period of at least:
m,i
 10 s for 1/3 octave bands from 100 Hz to 400 Hz,
 3 s for 1/3 octave bands from 500 Hz to 1,6 kHz,
 1 s for 1/3 octave bands from 2 kHz to 10 kHz.
The measurement shall be performed either:
a) by supplying the loudspeaker sequentially with a 1/3 octave band filtered pink noise signal such that the
square of the RMS voltage divided by the rated impedance equals 1 W. In this case the measured sound
pressure levels in each 1/3 octave band (L ) shall be corrected (L ) as follows:
m,i c,i
L = L −10×log (21) (1)
c,i m,i 10
b) by supplying the loudspeaker with a pink noise signal such that the square of the RMS voltage divided by
the rated impedance equals 1 W spread over the full range of frequencies (from 100 Hz to 10 kHz,
1/3 octave bands) and analysing the microphone output signal by means of 1/3 octave filters. In that
case:
L = L
c,i m,i
(2)
NOTE 1 The method described in a) is better suited for loudspeakers with low power drive unit(s), typically 1 W or less.
The method described in b) is preferred for loudspeakers with higher power drive unit(s).
NOTE 2 For loudspeakers with a rated noise power of less than 1 W, a pink noise signal of less than 1 W may be used
providing L is corrected accordingly.
c,i
The frequency response shall be plotted with the sound pressure levels L as a function of frequency in
c,i
1/3 octave bands. The 0 dB reference of the tolerance field (see Figure 1) shall be adjusted to give the best fit
with the frequency response curve.
5.1.5.3 Sensitivity calculation
The sensitivity S shall be given by the following equation:
L
c,i
 
i=21
( )
 
S= 10× log 10 dB (3)
∑
 
i=1
 
where L to L are the 1/3 octave sound pressure levels from 100 Hz to 10 kHz from the frequency
c,1 c,21
response curve.
5.1.6 Frequency response measurement and sensitivity calculation for loudspeakers requiring
dedicated system equalization
5.1.6.1 General
This test method shall be used for loudspeakers which have been designed to operate with an associated
active equalization network.
NOTE Testing of active equalizers is not covered by this European Standard.
5.1.6.2 Measuring arrangement
Measurements shall be made in accordance with Annex A.
An active equalizer inserted between the clipping network and the power amplifier shall be used in the
measurements.
5.1.6.3 Basic measurements
Basic measurements shall be performed as described in 5.1.5.2.
5.1.7 Provision for tests
The following shall be provided for testing compliance with this European Standard:
a) seven specimens of type A or nine specimens of type B loudspeaker with any mounting, accessories etc.;
b) the data required in 4.5.2.
The specimens submitted shall be representative of the manufacturer's normal production with regard to their
construction and settings.
5.1.8 Test schedule
The specimens shall
...