|KLIPPEL R&D System|
Rated noise voltage
Short-term maximum voltage
|TRF, PWT, LSI3, DIS, TBM, MTON|
Long-term maximum voltage
|PWT, LSI3, DIS|
Peak and rms value, crest factor
|PWT, LIS3, LAA|
Probability density function
Peak and rms value, crest factor, probability density function and the spectrum are the most important characteristics for describing voltage signal.
The maximal rms value input voltage, which can be handled by a transducer, depends on the properties of the stimulus and further measurement conditions (e.g. ambient temperature). The dominant limiting factors for the rms value are the maximal permissible voice coil temperature and the mechanical load caused by the high displacement at low frequencies and high values of strain and stress inside the material due to the acceleration at high frequencies. Significant harmonic and intermodulation distortion, symptoms of irregular defects (Rub & Buzz), thermal and nonlinear compression of the fundamental component indicate the upper limit of the usable working range. At critical amplitude, the transducer will be damaged. International standards as referenced below define the properties of filtered noise, sinusoidal signal, burst and other stimuli with particular ON/OFF cycle times, amplitude profiles for detecting the short-term and long-term values permissible for the particular transducer.
The figure to the left shows the rms value and peak value of the voltage versus measurement time using pink noise switched on and off according to fixed cycle times and increased by an amplitude profile.
LSI3 module identifies nonlinear parameters and thermal states which reveal the physical causes of the thermal and mechanical limits.
PWT is the perfect tool for finding the maximal input voltage while monitoring all state signals and the parameter variation during the test. PWT can monitor up to 2 devices under test (DUTs) by using the DA2 and up to 8 DUTs using the power monitor PM 8. An internal generator provides common test signals (noise, sinusoidal sweep) according various standards, including ON/OFF cycling and an amplitude profile for increasing the voltage. A death report monitors the destruction process at high resolution.
DIS module is a perfect tool for using the electrical input voltage using very short sinusoidal tones and monitoring the fundamental component (displacement or sound pressure), nonlinear distortion and other symptoms (e.g. dc displacement) in the large signal domain. A protection system may skip measurement at high amplitudes when the distortion or voice coil temperature exceeds a limit value.
TRF module can be used for generating sinusoidal burst having a shaped envelope of a few cycles to measure the maximal short term voltage (< 1s) which is limited more by mechanical load than by voice coil heating.
|Live Audio Analyzer (LAA)|
LAA allows to measure both voltage and current. Using either the internal noise generator, or a dedicated user defined test signal (as wave file), different tests like endurance testing or short bursts can be designed. No protection is applied, which allows for destructive testing with a high resolution death report.
|Multi-Tone Measurement (MTON)|
MTON module allows the measurement of the compression by comparing the transfer function of the device under test (DUT) at different voltage values. Maximal compression and distortion, as well as maximal temperature increase can be defined to avoid the destruction of the DUT during the measurement.
|Tone Brust Measurement (TBM)|
TBM module provides an automatic tone burst measurement sequence to measure different signals including voltage and current. Using a fully adjustable tone burst stimulus, the measurement is automatic repeated for a user defined set of frequencies with increased input level until the harmonic distortion threshold is reached.
Name of the Template
Diagnost. MIDRANGE Sp1
Comprehensive testing of midrange drivers with a resonance 30 Hz < fs < 200 Hz using standard current sensor 1
Diagnost. RUB&BUZZ Sp1
Batch of Rub & Buzz tests with increased voltage (applied to high power devices)
Diagnost. RUB & BUZZ Sp2
Batch of Rub & Buzz tests with increased voltage (applied to low power devices)
Diagnost. SUBWOOFER (Sp1)
Comprehensive testing of subwoofers with a resonance 10 Hz < fs < 70 Hz using standard current sensor 1
Diagnostics MICROSPEAKER Sp2
Comprehensive testing of microspeakers with a resonance 100 Hz < fs < 2 kHz using sensitive current sensor 2
Diagnostics TWEETER (Sp2)
Comprehensive testing of tweeters with a resonance 100 Hz < fs < 2 kHz using sensitive current sensor 2
Diagnostics VENTED BOX SP1
Comprehensive testing of vented box systems using standard current sensor 1
Diagnostics WOOFER (Sp1)
Comprehensive testing of subwoofers with a resonance 30 Hz < fs < 200 Hz using standard current sensor 1
Diagnostics WOOFER Sp1,2
Comprehensive testing of subwoofers with a resonance 30 Hz < fs < 200 Hz using current sensor 1 and 2
Equivalent Input Dist. AN 20
Equivalent input distortion according Application Note AN 20
Thermal Parameters (woofer)
Analysis of heat transfer in woofers based on identified thermal woofer parameters
Thermal Parameters AN 18
Thermal Parameters measured by using PWT module according Application Note 18
Thermal Parameters AN 19
Thermal Parameters measured by using PWT module according Application Note 19
LSI Tweeter Nonlin. Para Sp2
Tweeters with fs > 400 Hz at sensitive current sensor 2
LSI Headphone Nonlin. P. Sp2
Nonlinear parameters of headphones with fs < 300 Hz at sensitive current sensor 2
LSI Woofer Nonl. P. Sp1
Nonlinear parameters of woofers with fs < 300 Hz at standard current sensor 1
LSI Woofer Nonl.+Therm. Sp1
Nonlinear and thermal parameters of woofers with fs < 300 Hz at standard current sensor Sp1
LSI Woofer+Box Nonl. P Sp1
Nonlinear parameters of woofers operated in free air, sealed or vented enclosure with a resonance frequency fs < 300 Hz at standard current sensor Sp1
LSI Microspeaker Nonl. P. Sp2
Nonlinear parameters of microspeakers with fs > 300 Hz at sensitive current sensor 2
TRF Crest Harmonics (x,f)
Crest factor harmonic distortion versus displacement to find Rub & Buzz and other loudspeaker defects
TRF rubb+buzz w/o Golden Unit
Rub & Buzz detection without "Golden Unit" according Application Note AN 22
TRF rubb+buzz with Golden Unit
Rub & Buzz detection with "Golden Unit" according Application Note AN 23
DIS Compression Out(in)
Output amplitude versus input amplitude at four frequencies
DIS Harmonics vs. Voltage
Harmonic distortion measurement versus amplitude
DIS SPL, Harm protected
Harmonic distortion measurement with protection
SIM Compression Out(In)
Output amplitude versus input amplitude at four frequencies using large signal parameters imported from LSI; Simulated results are comparable with DIS Compression Out(In).
SIM Therm. Analysis (1 tone)
Heat transfer based on thermal parameters imported from LSI using a single-tone stimulus
SIM Therm. Analysis (2 tone)
Heat transfer based on thermal parameters imported from LSI using a two-tone stimulus
PWT 8 Woofers Param. ID Noise
Parameter identification of woofers using internal test signal (no cycling, no stepping)
PWT EIA accelerated life test
Accelerated life testing according EIA 426 B A. 4 using any external signal to monitor temperature, power and resistance
PWT IEC Long term Voltage
Power test to determine long-term maximal voltage according IEC 60268-5 paragraph 17.3 without parameter measurement for one device monitoring voltage, resistance, temperature and power
PWT IEC Short term Voltage
Power test to determine short term maximal voltage according IEC 60268-5 paragraph 17.2 without parameter measurement applied to 1 DUT monitoring temperature, power and resistance
PWT Powtest (fast Temp.)
Power test for fast monitoring of temperature, power and resistance without parameter measurement using external continuous signal (noise) supplied to IN1
PWT Powtest EXT. GENER.
Power test for monitoring temperature, power and resistance using external continuous signal (noise) supplied to IN1
PWT Powtest LIMITS
Power test to find maximal input voltage, power and temperature limits without parameter measurement applied to 1 DUT
PWT Powtest MUSIC
Power test without parameter measurement monitoring temperature, power, voltage and resistance using any external signal
|Rated Umax based on SPLmax, IEC 60268-21||Rated maximum input value U max according IEC 60268-21 by indirect measurement based on SPL max|
Audio Engineering Society
AES2 Recommended practice Specification of Loudspeaker Components Used in Professional Audio and Sound Reinforcement
Consumer Electronics Association
CEA-426-B Loudspeakers, Optimum Amplifier Power
European Telecommunications Standards Institute
EIA 426B Loudspeaker Power Rating Test CD provided by ALMA International
International Electrotechnical Commission
IEC 60268-5 Sound System Equipment, Part 5: Loudspeakers
Y. Shen, “Accelerated Power Test Analysis Based on Loudspeaker Life Distribution,” presented at the 124th Convention of Audio Eng. Soc., May 2008, Preprint 7345.
W. Klippel, “Nonlinear Modeling of the Heat Transfer in Loudspeakers,” J. of Audio Eng. Soc. 52, Volume 1, 2004 January.
C. Zuccatti, “Thermal Parameters and Power Ratings of Loudspeakers,” J. of Audio Eng. Soc., Volume 38, No. 1, 2, 1990 January/February.
K. M. Pedersen, “Thermal Overload Protection of High Frequency Loudspeakers,” Report of Final Year Dissertation at Salford University.
Henricksen, “Heat Transfer Mechanisms in Loudspeakers: Analysis, Measurement and Design,” J. of Audio Eng. Soc., Volume 35, No. 10, 1987 October.