FOREWORD
1 Scope
2 Normative references
3 Conditions for measurement
   3.1 General conditions
   3.2 Measuring conditions
4 Test signals
   4.1 General
   4.2 Sinusoidal signal
   4.3 Broadband noise signal
   4.4 Narrow-band noise signal
   4.5 Impulsive signal
5 Acoustical environment
   5.1 General
   5.2 Free-field conditions
   5.3 Half-space free-field conditions
   5.4 Diffuse sound field conditions
   5.5 Simulated free-field conditions
   5.6 Half-space simulated free-field conditions
6 Unwanted acoustical and electrical noise
7 Positioning of loudspeaker and measuring
   microphone
   7.1 Measuring distance under free-field and
        half-space free-field conditions
   7.2 Positioning of loudspeaker in diffuse field conditions
   7.3 Positioning of loudspeaker and microphone in
        simulated free-field conditions
8 Measuring equipment
9 Accuracy of the acoustical measurement
10 Mounting of loudspeakers
   10.1 Mounting and acoustic loading of drive units
   10.2 Mounting and acoustic loading of a loudspeaker
        system
11 Standard baffle and measuring enclosures
   11.1 Standard baffle
   11.2 Standard measuring enclosures
12 Preconditioning
13 Type description
   13.1 General
   13.2 Loudspeaker drive units
   13.3 Loudspeaker system
14 Marking of terminals and controls
   14.1 General
   14.2 Positive terminal
15 Reference plane, reference point and reference axis
   15.1 Reference plane - characteristic to be specified
   15.2 Reference point - characteristic to be specified
   15.3 Reference axis - characteristic to be specified
16 Impedance and derivative characteristics
   16.1 Rated impedance - characteristic to be specified
   16.2 Impedance curve
   16.3 Total Q-factor (Q[t])
   16.4 Equivalent air volume of a loudspeaker drive unit
        compliance (V[as])
17 Input voltage
   17.1 Rated noise voltage
   17.2 Short-term maximum input voltage
   17.3 Long-term maximum input voltage
   17.4 Rated sinusoidal voltage
18 Input electrical power
   18.1 Rated noise power - characteristic to be specified
   18.2 Short-term maximum power - characteristic to be specified
   18.3 Long-term maximum power - characteristic to be specified
   18.4 Rated sinusoidal power - characteristic to be specified
19 Frequency characteristics
   19.1 Rated frequency range - characteristic to be specified
   19.2 Resonance frequency
   19.3 Tuning frequency of a bass reflex or passive radiator
        loudspeaker system - characteristic to be specified
20 Sound pressure under free-field and half-space
   free-field conditions
   20.1 Sound pressure in a stated frequency band
   20.2 Sound pressure level in a stated frequency
        band - characteristic to be specified
   20.3 Characteristic sensitivity in a stated frequency band
   20.4 Characteristic sensitivity level in a stated frequency
        band - characteristic to be specified
   20.5 Mean sound pressure in a stated frequency band
   20.6 Mean sound pressure level in a stated frequency band -
        characteristic to be specified
21 Response under free-field and half-space free-field
   conditions
   21.1 Frequency response
   21.2 Effective frequency range
   21.3 Transfer function
22 Output power (acoustic power)
   22.1 Acoustic power in a frequency band
   22.2 Mean acoustic power in a frequency band
   22.3 Efficiency in a frequency band
   22.4 Mean efficiency in a frequency band
23 Directional characteristics
   23.1 Directional response pattern
   23.2 Radiation angle
   23.3 Directivity index
   23.4 Coverage angle or angles
24 Amplitude non-linearity
   24.1 Total harmonic distortion
   24.2 Harmonic distortion of the n[th] order
        (where n = 2 or n = 3)
   24.3 Characteristic harmonic distortion
   24.4 Modulation distortion of the n[th] order
        (where n = 2 or n = 3)
   24.5 Characteristic modulation distortion of the nth order
        (where n = 2 or n = 3)
   24.6 Difference frequency distortion (of the second
        order only)
25 Rated ambient conditions
   25.1 Temperature ranges
   25.2 Humidity ranges
26 Stray magnetic fields
   26.1 Static components
   26.2 Dynamic components
27 Physical characteristics
   27.1 Dimensions
   27.2 Mass
   27.3 Cable assemblies
28 Design data
29 Indication of the characteristics to be specified
Annex A (informative) Standard measuring enclosure
        type A
Annex B (informative) Standard measuring enclosure
        type B
Annex C (informative) Definitions of terms used in
        Clause 13
Annex D (informative) Listening tests
Bibliography