1、BSI Standards PublicationMultimedia systems Guide to the recommended characteristics of analogue interfaces to achieve interoperabilityBS EN 61938:2013National forewordThis British Standard is the UK implementation of EN 61938:2013. It is identical to IEC 61938:2013. It supersedes BS EN 61938:1997 w
2、hich is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/100, Audio, video and multimedia systems and equipment.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all t
3、he necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 84038 8ICS 33.160.60; 35.200Compliance with a British Standard cannot confer immunity fromlegal obligations.This Briti
4、sh Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 61938:2013EUROPEAN STANDARD EN 61938 NORME EUROPENNE EUROPISCHE NORM September 2013 CENELEC European
5、Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide
6、 for CENELEC members. Ref. No. EN 61938:2013 E ICS 33.160.01; 35.200 Supersedes EN 61938:1997 English version Multimedia systems - Guide to the recommended characteristics of analogue interfaces to achieve interoperability (IEC 61938:2013) Systmes multimdia - Guide des caractristiques recommandes de
7、s interfaces analogiques permettant dobtenir linteroprabilit (CEI 61938:2013) Multimedia Systeme - Leitfaden fr empfohlene Charakteristiken analoger Schnittstellen zur Erreichung von Kompatibilitt (IEC 61938:2013) This European Standard was approved by CENELEC on 2013-08-01. CENELEC members are boun
8、d 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 CE
9、N-CENELEC Management Centre or to any CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management
10、Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland,
11、Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 61938:2013EN 61938:2013 - 2 - Foreword The text of document 100/2130/FDIS, future edition 2 of IEC 61938, prepared by
12、IEC/TC 100 “Audio, video and multimedia systems and equipment“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61938:2013. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national sta
13、ndard or by endorsement (dop) 2014-05-01 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-08-01 This document supersedes EN 61938:1997. EN 61938:2013 includes the following significant technical changes with respect to EN 61938:1997: the main
14、title was changed to: Multimedia systems - Guide to the recommended characteristics of analogue interfaces to achieve interoperability; the scope was adapted to the title; a new introduction has been added. The necessity of the above revisions is mentioned in this introduction; the values in each ta
15、ble were chosen with respect to the state of the art and representative of best practice in industry; plug-in power systems and soundcard power systems are added; a new Subclause 12.3 has been created: Interoperability of portable audio headphones /earphones and portable audio equipment; a new Annex
16、 A describing pairing and screening of conductors is added; a new Annex B describing phantom power variants for specialized applications is also added. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not b
17、e held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61938:2013 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the
18、standards indicated: IEC 60027 Series NOTE Harmonised as EN 60027 Series (not modified). IEC 61293:1994 NOTE Harmonised as EN 61293:1994 (not modified). BS EN 61938:2013- 3 - EN 61938:2013 Annex ZA (normative) Normative references to international publications with their corresponding European publi
19、cations The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
20、 NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60038 (mod) 2009 IEC standard voltages EN 60038 2011 IEC 60094-2 + corr. March 1994 1995 Magnetic tape sound recording and reproduc
21、ing systems - Part 2: Calibration tapes EN 60094-2 1995 IEC 60107-6 1989 Recommended methods of measurement on receivers for television broadcast transmissions - Part 6: Measurements under conditions different from broadcast signal standards HD 567.6 S1 1990 IEC 60130-9 2011 Connectors for frequenci
22、es below 3 MHz - Part 9: Circular connectors for radio and associated sound equipment EN 60130-9 2011 IEC 60268-1 + A1 + A2 1985 1988 1988 Sound system equipment - Part 1: General HD 483.1 S2 -1)-1989 - - IEC 60268-3 2000 Sound system equipment - Part 3: Amplifiers EN 60268-3 + corr. January 2) 2000
23、 2002 IEC 60268-5 + A1 2003 2007 Sound system equipment - Part 5: Loudspeakers EN 60268-5 + A1 2003 2009 IEC 60268-7 2010 Sound system equipment - Part 7: Headphones and earphones EN 60268-7 2011 IEC 60268-11 + A1 + A2 1987 1989 1991 Sound system equipment - Part 11: Application of connectors for th
24、e interconnection of sound system components HD 483.11 S3 - -3) 1993 - - IEC 60268-12 + A1 + A2 1987 1991 1994 Sound system equipment - Part 12: Application of connectors for broadcast and similar use EN 60268-12 - 4)+ A21995 - 1995 IEC 60603-11 1992 Connectors for frequencies below 3 MHz for use wi
25、th printed boards - Part 11: Detail specification for concentric connectors (dimensions for free connectors and fixed connectors) - - 1) HD 483.1 S2 includes A1 to IEC 60268-1. 2) EN 60268-3 is superseded by EN 60268-3:2013, which is based on IEC 60268-3:2013. 3) HD 483.11 S3 includes A1 + A2 to IEC
26、 60268-11. 4) EN 60268-12 includes A1 to IEC 60268-12. BS EN 61938:2013EN 61938:2013 - 4 - Publication Year Title EN/HD Year IEC 60958 Series Digital audio interface EN 60958 Series ITU-R BT.1700 2005 Characteristics of composite video signals for conventional analogue television systems - - BS EN 6
27、1938:2013 2 61938 IEC:2013 CONTENTS INTRODUCTION . 7 1 Scope . 8 2 Normative references . 10 3 Terms and definitions . 10 4 General conditions 13 5 Power supply 13 5.1 Alternating current (a.c.) power supply voltages and frequencies 13 5.2 Direct current (d.c.) power supply voltages . 13 5.3 Power s
28、upply feed for microphones 14 6 Interconnections . 14 6.1 Connections 14 6.1.1 General . 14 6.1.2 Characteristics of cables . 14 6.2 Connectors 15 7 Marking and symbols for marking . 16 7.1 Marking . 16 7.2 Symbols for marking 16 8 Electrical recommended values 16 8.1 General purpose output/input 16
29、 8.2 General purpose audio output/input . 16 8.2.1 Audio-only interfaces for consumer equipment . 16 8.2.2 Interfaces for professional equipment and consumer equipment where audio and video signals are present on the same connector or cable . 18 8.3 General purpose video input/output . 19 9 Interope
30、rability of microphones and amplifiers 19 9.1 Microphones (excluding piezoelectric types) . 19 9.2 Power supply feed for electret microphones fed over a signal conductor (“plug-in power”) 20 9.3 Power supply feed for electret microphones fed by a separate conductor (“soundcard power” or “PC power”)
31、. 21 9.4 Phantom supply system 21 9.4.1 General . 21 9.4.2 Supply voltage polarity 22 9.4.3 Circuit diagram 22 9.4.4 Value of the supply voltage . 22 9.4.5 Supply current . 22 9.4.6 Marking . 22 9.5 A-B supply system 23 9.5.1 General . 23 9.5.2 Output impedance of the microphone 23 9.5.3 Circuit dia
32、gram 23 9.5.4 Connection of the power supply to earth . 23 9.5.5 Marking . 23 9.6 Polarity of the audio frequency voltage . 23 BS EN 61938:201361938 IEC:2013 3 10 Interoperability of record-playing units (pick-ups) and amplifiers . 26 11 Interoperability of loudspeakers and amplifiers . 26 11.1 Sing
33、le unit loudspeakers . 26 11.2 Loudspeaker systems 26 11.2.1 Loudspeakers with built-in amplifier . 26 11.2.2 Impedance-defined loudspeaker systems 27 11.2.3 Constant voltage loudspeaker systems 27 11.3 Voltage (or power) interoperability of amplifiers and loudspeakers 27 11.3.1 Overview . 27 11.3.2
34、 Interoperability requirements . 28 11.4 Polarity of the sound pressure . 28 12 Interoperability of headphones and amplifiers . 28 12.1 General . 28 12.2 Interoperability of headphones with stationary amplifiers 28 12.3 Interoperability of portable audio headphones/earphones and portable audio equip
35、ment . 29 12.3.1 General . 29 12.3.2 Portable audio headphones/earphones 29 12.3.3 Portable audio equipment 29 12.3.4 Recommended values and input/output values for portable audio headphones/earphones and portable audio equipment 29 13 Interoperability of amplifiers with other amplifiers . 30 13.1 P
36、re-amplifiers and power amplifiers for general purpose and sound reinforcement 30 13.2 Broadcast and similar line amplifiers . 31 Annex A (informative) Pairing and screening of conductors . 32 Annex B (informative) Phantom power variants for specialized applications . 33 Bibliography 34 Figure 1 Aud
37、io and video sources and destinations . 9 Figure 2 Example of plug-in power system for a single microphone . 24 Figure 3 Example of plug-in power system for a two-channel microphone . 24 Figure 4 Example of soundcard power system . 24 Figure 5 Example of phantom power supply system 25 Figure 6 Examp
38、le of A-B power supply system 25 Table 1 Direct current (d.c.) power supply voltages and tolerances . 14 Table 2 General purpose values for audio-only interfaces 16 Table 3 General purpose values for audio signals for professional interfaces . 18 Table 4 General purpose recommended values for video
39、signals 19 Table 5 Recommended values for microphones and amplifiers 20 Table 6 Required values for phantom supply systems . 25 Table 7 Required values for A-B power supply systems 25 Table 8 Recommended values for analogue record-playing units and amplifiers 26 Table 9 Recommended values for impeda
40、nce-defined loudspeaker systems 27 Table 10 Recommended values for constant voltage loudspeaker systems 27 BS EN 61938:2013 4 61938 IEC:2013 Table 11 Recommended values for headphones and amplifiers in stationary applications 29 Table 12 Recommended values for portable audio headphones/earphones and
41、 portable audio equipment . 30 Table 13 Recommended values for pre-amplifiers and power amplifiers 31 Table 14 Recommended values for broadcast and similar line amplifiers 31 BS EN 61938:201361938 IEC:2013 7 INTRODUCTION The first edition of IEC 61938 was derived from IEC 60268-15, IEC 60574-4 and I
42、EC 60933-1 and also from related proposals which had been submitted up until the date of this revision. IEC 60268-15 was the first standard to address interoperability the ability of equipment from different manufacturers to be assembled into a system with full compatibility at every interface. Howe
43、ver, the purpose, terminology and implications of IEC 61938 are now widely misunderstood because the words matching and preferred used in IEC 61938, are frequently misinterpreted, resulting in IEC 61938 being regarded as a performance standard, which was never its intention. The aim of this revision
44、 is to make the intention of this standard easily comprehensible by using widely used terminology in the title and text of the standard. The features of the revision are the following. a) Unification and arrangement of existing related standards, including effective proposals which have been submitt
45、ed. b) The concept of “general purpose input/output“. NOTE The standard numbers mentioned above correspond to the revised numbers, if applicable. BS EN 61938:2013 8 61938 IEC:2013 MULTIMEDIA SYSTEMS GUIDE TO THE RECOMMENDED CHARACTERISTICS OF ANALOGUE INTERFACES TO ACHIEVE INTEROPERABILITY 1 Scope T
46、his International Standard gives guidance on current practice for the characteristics of multimedia analogue interfaces to achieve interoperability between equipment from different manufacturers. It is not a performance standard. Recommendations for interfaces for equipment used in vehicles, and for
47、 analogue video interfaces for broadcast and similar equipment, are not given. Refer to IEC 60958 for the interconnection of digital signals. Figure 1 shows in a diagram the possible interfaces of the audio and video sources and destinations. BS EN 61938:201361938 IEC:2013 9 NOTE The numbers indicat
48、ed above the arrows refer to the appropriate clause or subclauses of this standard. Figure 1 Audio and video sources and destinations LowVoltage sourcesMicrophoneRecord playerHigh/low sensitivityLow Voltage or RF level 9.1100 , 5V rated level Power level 12/1 GHzconverter12/1 GHzconverterDigital sat
49、elliteradio tunerSatellite TV tunerAnalogue or digital8.28.312.2HeadphonesRealtimesignalsourcesRadio orTVbroadcastTerrestrial TV tunerAnalogue or digital8.28.3AuxiliaryAM/FM radio tunerMicrophoneVideo camera or camcorderVideo tape recorderAudio tape cassetterecorder analogueDigital audio tape recorder :DAT,DCC,Minidisc,CD writeable recorderCD/CD-i/CD-ROMLaservision player9.1Realtimesignalsourcesor pre-recorded signalsActiveloudspeakerboxesAudio poweramplifie
