IEC 60268-22:2020 applies to transducers converting an electrical input signal into a mechanical or acoustical output signal. However, if the electrical input terminals and the surface of the radiator are accessible, this document can also apply to passive and active sound systems such as loudspeakers, headphones, TV-sets, multi-media devices, personal portable audio devices, automotive sound systems and professional equipment. This document describes only electrical and mechanical measurements that help assess the transfer behaviour of the device under test (DUT). This includes operating the DUT in both the small- and large-signal domains. The influence of the target application’s acoustical boundary conditions (e.g. car interior) can also be considered in the physical evaluation of the sound system. Perception and cognitive evaluations of the reproduced sound and the impact of perceived sound quality are outside the scope of this document.<\/p>\n
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| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions 3.2 Abbreviated terms 4 Type description 5 Marking of terminals and controls 6 Physical characteristics 6.1 Dimensions <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 6.2 Mass 6.3 Connectors and cable assemblies 7 Conditions 7.1 Rated conditions 7.2 Climatic conditions 7.2.1 Conditions for normal testing 7.2.2 Conditions for climatic testing 7.3 Standard measuring conditions <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 8 Test signals 8.1 General 8.2 Small-signal condition 9 Acoustical environment 9.1 General 9.2 Free-field conditions <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 9.3 Half-space, free-field conditions 9.5 Target application conditions 9.6 Vacuum condition 9.6.1 General 9.6.2 Method of measurement 9.7 Plane-wave tube condition 9.8 Non-acoustical measurement condition <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 10 Positioning of the radiator 10.1 Rated geometrical conditions 10.1.1 General 10.1.2 Reference plane and normal vector 10.1.3 Reference point 10.1.4 Orientation vector Figures Figure 1 \u2013 Rated conditions used to describe the geometry and position of the radiator in the coordinate system <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 10.2 Target application condition 11 Measurement equipment and test results 12 Accuracy of the mechanical and electrical measurement 13 Mounting of the DUT 13.1 Mounting and acoustic loading of drive units <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 13.2 Mounting and acoustic loading of an electro-acoustic system 13.3 Requirements for laser vibrometry 14 Preconditioning 15 Rated ambient conditions 15.1 Temperature ranges 15.1.1 Performance limited temperature range 15.1.2 Damage limited temperature range 15.2 Humidity ranges 15.2.1 Relative humidity range <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 15.2.2 Damage limited humidity range 16 Electrical signals at transducer terminals 16.1 Rated maximum input value 16.1.1 Conditions to be specified 16.1.2 Direct measurement <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 17 Electrical input power 17.1 Real input power 17.2 Power dissipated in DC resistance <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 17.3 Power dissipated in rated impedance 17.4 Rated maximum input power 18 Electrical input impedance 18.1 Complex electrical impedance 18.1.1 General 18.1.2 Method of measurements <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 18.2 Rated Impedance: characteristic to be specified 19 Vibration of the radiator surface 19.1 General 19.2 Displacement of a surface point rr 19.2.1 General <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 19.2.2 Method of measurements 19.3 Reference displacement 19.3.1 General 19.3.2 Methods of measurement <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 19.4 Peak and bottom displacement 19.4.1 General 19.4.2 Method of measurements 19.5 DC displacement 19.5.1 General <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 19.5.2 Method of measurements 19.6 Displacement transfer function 19.6.1 General 19.6.2 Method of measurements 19.7 Accumulated acceleration level 19.7.1 General <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 19.7.2 Method of measurements 20 Small-signal lumped parameters 20.1 General Figure 2 \u2013 Equivalent electrical network representing the electrical input impedance using the LR2 model for the lossy inductance of an electro-dynamical transducer <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 20.2 Electrical parameters 20.2.1 General 20.2.2 DC resistance 20.2.3 Lossy inductance <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 20.2.4 Electrical representation of the fundamental resonator 20.3 Relative lumped parameters 20.3.1 General <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 20.3.2 Resonance frequency 20.3.3 Electrical quality factor 20.3.4 Mechanical quality factor <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 20.3.5 Total quality factor Figure 3 \u2013 Analogous lumped parameter network representing the electrical, mechanical and acoustical elements at low frequencies <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 20.4 Lumped mechanical parameters 20.4.1 General 20.4.2 Method of measurements <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 20.5 Pure lumped mechanical parameters 20.5.1 General 20.5.2 Method of measurements 20.6 Compliance versus frequency 20.6.1 General 20.6.2 Method of measurements <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 20.7 Distributed mechanical parameters 20.7.1 Receptance <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 20.7.2 Modal analysis 20.7.3 Relative rocking level <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 20.7.4 Centre of gravity Figure 4 \u2013 Asymmetrical mass distribution function DM(y,z0) in the mechanical system of a microspeaker that shifts the centre of gravity away from the pivot point <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 20.7.5 Centre of stiffness 20.7.6 Centre of force factor <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 20.8 Lumped acoustical parameters 20.8.1 Mechano-acoustical coupling function 20.8.2 Effective radiation area <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 20.8.3 Acoustical load impedance <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 20.8.4 Lumped parameters of a coupled resonator Figure 5 \u2013 Equivalent electrical network of a transducer operated in a baffle represented by pure mechanical elements and additional acoustical elements <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Figure 6 \u2013 Equivalent electrical network representing the electrical input impedance of a vented loudspeaker system <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 21 Electro-acoustical efficiency 21.1 Reference efficiency 21.1.1 General 21.1.2 Methods of measurement <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 21.2 Passband efficiency 21.2.1 General 21.2.2 Method of measurement 22 Sensitivity 22.1 Reference sensitivity <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | 22.2 Passband sensitivity 23 Large-signal characteristics 23.1 Electrical and mechanical nonlinearities 23.1.1 Nonlinear stiffness KMS(x) <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | 23.1.2 Nonlinear force factor 23.2 Other loudspeaker nonlinearities 23.3 Asymmetry of the nonlinearity 23.3.1 Stiffness asymmetry AK <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | 23.3.2 Force factor asymmetry ABl 23.3.3 Force factor symmetry point xsym <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | 23.4 Offset from reference rest position, xoff 23.4.1 General 23.4.2 Method of measurement Figure 7 \u2013 Nonlinear force factor characteristic of an electro-dynamical transducer <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 23.5 Maximum reference displacement 23.5.1 Clearance to the boundaries <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 23.5.2 Mechanical limited peak displacement, Xmech 23.5.3 Distortion limited peak displacement, XMAXd <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 23.5.4 Compliance-limited displacement xC 23.5.5 Force-factor-limited displacement xBl 24 Thermal characteristics 24.1 General 24.2 Increase in voice coil temperature 24.2.1 General <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | 24.2.2 Methods of measurement 24.3 Effective thermal resistance 24.3.1 General 24.3.2 Method of measurement 24.4 Thermal parameters 24.4.1 General 24.4.2 Method of measurement <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | 24.5 Thermal time constant of the voice coil 24.5.1 General 24.5.2 Method of measurement 24.6 Thermal bypass factor 25 Time variance of the loudspeaker characteristics 25.1 Fatigue and load induced aging 25.1.1 General <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | 25.1.2 Stiffness versus apparent work 25.1.3 Parameters of the load induced aging model <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 25.1.4 Stiffness versus ambient temperature 26 Measurement uncertainty <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | Annex A (informative)Practical application guide Table A.1 \u2013 Important characteristics and their application <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Sound system equipment – Electrical and mechanical measurements on transducers<\/b><\/p>\n |