BS 6840-6:1987

National foreword
Committees responsible
1. Scope
2. Object
Chapter I: Conditions for specification and measurement
3. General conditions
4. Rated conditions and normal working conditions
Chapter II: Characteristics to be specified and the
            relevant measuring methods
Section One - Auxiliary passive elements. Diagram
5.1 Structure diagram (block schematic)
6. Terminals and controls
6.1 Marking
6.2 Symbols for marking
7. Input characteristics
7.1 Rated source impedance
7.2 Input impedance
7.3 Rated source e.m.f.
8. Output characteristics
8.1 Rated load impedance
8.2 Output impedance
9. Limiting characteristics
9.1 Overload source e.m.f.
9.2 Temperature limited input voltage
10. Attenuation
10.1 Rated matched insertion loss
10.2 Voltage attenuation (insertion attenuation)
11. Response
11.1 Frequency response
11.2 Effective frequency range
11.3 Phase-frequency response
12. Amplitude non-linearity
12.1 Harmonic distortion
12.2 Distortion curves
13. Unbalance
13.1 Unbalance of the input
13.2 Unbalance of the output
14. External influences
14.1 General
14.2 Rated equivalent source e.m.f. for external
     magnetic fields of power supply frequency
14.3 Residual equivalent source e.m.f. for external
     magnetic fields of power supply frequency
15. Magnetic stray field
15.1 Magnetic stray field generated by the passive
     element
16. Alignment
16.1 Attenuation alignment
16.2 Phase alignment
Section Two - Widely used passive elements
17. Attenuators
17.1 Residual attenuation
17.2 Attenuation range
17.3 Attenuation steps
17.4 Ultimate attenuation
18. Transformers
18.1 Impedance ratio
18.2 Voltage ratio
18.3 Rated output power
18.4 Limiting direct current
19. Filters and equalizers
19.1 Reference frequency response
19.2 Tone control range
Section Three - Physical characteristics and cable
                assemblies
20. Dimensions
21. Weight
22. Cable assemblies
Section Four - Classification of the characteristics to
               be specified
23. General
24. Classification
Appendix A
Figures

Characteristics and their methods of measurement for auxiliary passive elements i.e. attenuators, transformers, filters and equalizers, applied as separate units or combined with other separate elements to constitute a complete sound system.

Auxiliary passive elements shall be understood to include such elements as attenuators, transformers, filters and equalizers, applied as separate units to be combined with other separate sound system units to constitute a complete sound system.

Notes 1. – Auxiliary passive elements which are intended to be mounted as components in a sound system unit and to form a non-interchangeable part of such a unit, are not within the scope of this Recommendation.

Some characteristics are to be specified for all types of auxiliary passive elements. These are given in Chapter I and Section One. Further characteristics to be specified for the different types of auxiliary passive elements are given in Section Two, Clauses 17, 18 and 19.

2. – Auxiliary elements may sometimes include electronic amplification, in which case these elements are considered as amplifiers and are dealt with in IEC Publication 268-3, Sound System Equipment, Part 3: Sound System Amplifiers.

3. – If a network has more than four terminals as e.g. a cross-over network, it is nevertheless treated in this Recommendation as an assembly of four terminal networks.