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Loudspeaker Testing

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System OverviewSoundCheckTM is an easily configurable, Windows-based system for efficient and comprehensivetesting of loudspeakers.

Applications include:• High-speed production testing• Research and development• Incoming inspection• Vendor auditing

Production TestingSoundCheck is a fast and accurate system forproduction line testing. All quality-relatedparameters – both acoustical and electrical – aremeasured simultaneously, resulting in fast andthorough loudspeaker evaluation. SoundCheck’sunique stepped sine excitation signal (Stweep™)permits such detailed tests to be performed in aslittle as 3 seconds without sacrificing test accuracy,and its proprietary HarmonicTrak™ algorithmmaintains measurement accuracy even in noisyenvironments.

The software can be configured for one-clickaccess to commonly used tests, and variouslevels of operator control can be assigned toprevent modification of the test sequence.Results can be presented as a simple pass/failindication, or a detailed failure mode analysis.Pass/Fail limits can be user-defined, determinedby offsetting data from a measurement (e.g. ±3dBfrom the response curve of a referenceloudspeaker), or determined statistically usingSoundCheck’s statistical analysis module.Detailed results can be exported to otherprograms for additional processing, statisticalcontrol, and generating documents instandardized formats.

SoundCheck interfaces with barcode readers,footswitches, and other digital I/O devices suchas TTL controlled relays, RS-232, and IEEE-488to integrate fully with automatic production lines.

R&D ApplicationsSoundCheck is a powerful and flexible tool for theR&D laboratory. Its advanced measurementalgorithms enable rapid characterization ofprototypes, performing comprehensive tests suchas frequency response, phase, sensitivity,

distortion, directivity, impedance, and Thiele-Smallparameters in a matter of seconds. SoundCheck isavailable with either a sound card or with NationalInstrument’s data acquisition cards for highprecision measurements.

SoundCheck offers unrivalled flexibility at everystage in the test process. Input test signals includesine, noise, and any signal stored as a WAV file(e.g. multi-tone, impulse, tone burst, etc.).Customized test sequences are easily developedusing SoundCheck’s unique point and clickinterface. SoundCheck can be easily incorporated

Typical Tests• Frequency response• Phase• Distortion• Rub & Buzz• Polarity• Impedance• Sensitivity• Polar plots• THD• Sound pressure level• Power rating tests• FFT and Real Time analyses

Features and Benefits

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Loudspeaker TestingTypical System Configuration

A typical loudspeaker test system consists of the SoundCheck Basic Software with optional Distortion, Post-Processing, Simulated Free-Field and Equation Editor modules, computer, sound card, audio amplifier, imped-ance box, microphone, and microphone power supply (options may vary depending upon application).

Same System for R&D and ProductionWith a common system for R&D and for theproduction line, it is easy for the tests developed byengineering to be performed on the production line.Identical virtual laboratories can be recreatedaround the world, making it easy for manufacturingto carry out the same tests as engineering, even ifthey are thousands of miles away.

Virtual Audio Test BenchThe SoundCheck software includes a virtual audiotest bench. This includes a Signal Generator,Multimeter, Real Time Analyzer, Oscilloscope andSpectrum Analyzer. These virtual instrumentsprovide exactly the same functionality as theirexpensive hardware equivalents, avoiding the needto purchase any additional stand-aloneinstrumentation.

One System, Many OptionsSoundCheck is a modular system. Whether youwant a basic sound card based system forproduction line testing of loudspeakers, or asophisticated R&D system with NationalInstrument’s PXI-4461 dynamic signal acquisitionmodule, for high accuracy laboratorymeasurements, we have a system to match yourrequirements and your budget.

Output to Speaker& Impedance Box

SoundCard LInput

Sound Card Output

to Amp Input

PASSED

SoundCheck™Loudspeaker

Testing

Power Amplifier

SoundConnect

Mic PowerSupply

SCM Measurement Mic

SoundCard RInput

SpeakerUnder Test

into existing test programs that utilize ActiveXcontrols or National Instruments LabVIEW®.

Analysis tools include a FFT analyzer and anoptional real time analyzer (RTA), which providesthe R&D engineer with 1/1, 1/3, 1/6, 1/12, and 1/24octave analysis. An optional analysis moduleenables the measurement of a loudspeaker’s free-field response and free-field harmonic distortion in anon-anechoic environment using a continuouslogarithmic sine sweep. Soundcheck’s post-processing editor has many pre-programmedroutines including Thiele-Small parameters, curvefitting to determine resonances, arithmeticoperations, curve smoothing, and statistical

functions. SoundCheck can also record theloudspeaker’s response as a WAV file for additionalanalysis.

Loudspeaker Specification Sheet