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Voltage and current

Characteristics:

KLIPPEL R&D System

Rated noise voltage

PWT, LSI

Short term maximum voltage

TRF, PWT, LSI, DIS

Long term maximum voltage

PWT, LSI, DIS

Peak and rms value, crest factor

PWT, LSI

Probability density function

PWT, LSI

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 above 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.
The figure above 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.

KLIPPEL R&D SYSTEM (development)

Module

Comment

Large Signal Identification (LSI)

LSI module identifies nonlinear and thermal parameters which reveal the physical causes of the thermal and mechanical limits.

Power Test (PWT)

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.

3D Distortion Module (DIS)

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.

Transfer Function Module (TRF)

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.

Templates of KLIPPEL products

Name of the Template

Application

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

Standards:

  • IEC Standard IEC 60268-5 Sound System Equipment, Part 5: Loudspeakers
  • AES2-1984 AES Recommended practice Specification of Loudspeaker Components Used in Professional Audio and Sound Reinforcement
  • CEA CEA-426-B Loudspeakers, Optimum Amplifier Power
  • EIA 426B Loudspeaker Power Rating Test CD provided by ALMA International


Papers and Preprints:

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.