Klippel Analyzer System Receives Software Updates for Testing DSP-Based Audio Devices

November 17 2020, 00:35
Klippel has been keeping busy in the last months, continuously improving their measurement technology for loudspeakers and audio systems. With the dB-Lab 210.918 and QC 6.7 software updates, Klippel introduced new tools for testing DSP-enhanced speakers, headphones and connected audio systems, first with and hardware add-on for the SCN Scanning Vibrometer, and second with an extension for automatic testing at multiple excitation levels using the TRF module.
Klippel Scanning Vibrometer System (SCN) Near Field Add-On.

The Klippel Analyzer System has received another minor software update for both R&D and QC applications. This free of charge update for users of dB-Lab version 210 or QC 6, respectively provides two new relevant tools for output-based testing of contemporary DSP-enhanced speakers, headphones and other audio systems according to the IEC 60268-21 standard.

This includes an hardware add-on for the Klippel Scanning Vibrometer System (SCN), allowing new powerful possibilities for acoustic testing. As the German company explains, the hardware is extended with a microphone in addition to the existing laser sensor. Together with a baffle for measuring transducers up to 10" (30 cm) in diameter or compact (smart) speakers, it provides acoustic near field scanning technology to the SCN.
This allows comprehensive calculations of near & far-field radiation data, such as directional characteristics and sound power as well as sound pressure output at any point in a 3D half-space. This data is extrapolated from a double shell acoustic measurement and holographic processing for direct sound separation. This is the same technology used before in the Klippel Near Field Scanner (NFS), now available for the much smaller SCN hardware.
Holographic processing and Direct Sound Separation. Directivity plot for an infinite baffle compensating finite dimension and edge effects.

Setups using much larger and often still insufficient baffles can be replaced. The SCN equipped with the new SCN Near Field Add-On enables mechanical, electrical and acoustical measurements in a very compact space, not requiring an anechoic room - a normal reverberant room such as a (home) office is sufficient. And the automated axis control ensures repeatable, precise and fast positioning of microphone and laser sensors.

As Klippel anticipates, this add-on will be available in early 2021. However, beta testers are very welcome to get their hands on the new test equipment and should get in contact with Klippel if interested.

TRF Module Extension
The Transfer Function Measurement (TRF) module also got an extension for automatic testing at multiple excitation levels. The new TRF Voltage Stepping (STEP) module (Pre-Release) works with the TRF operation, simplifying the test procedure and the graphical result display. Limits can be applied to help easily rate Umax and SPLmax in accordance with IEC 60268-21.
STEP module controls multiple measurements.
Furthermore, the STEP module can be used for detailed analysis. For additional information, the measurement data can be automatically forwarded to the Time-Frequency-Analysis (TFA) module or, for perceptual analysis, to the Audio Player Module (PLAY).
Root cause analysis of defects using STEP.
The image above illustrates root cause analysis of a Rub & Buzz defect in order to trace down to where the defect occurs (excursion), at which frequency this problem happens and what the isolated defect symptom sounds like when separated from the fundamental component.

Both extensions complement Klippel’s transducer and audio system diagnostic tools and are fully compliant with IEC 60268-21.

More information about the new software update and hardware add-on are available on the company's website. 
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