End of Line Distortion Measurements

Steve Temme discusses the importance of detecting manufacturing-induced defects such as Rub & Buzz and Loose Particles during end-of-line testing, and explains the various algorithms that are used. He compares conventional and perceptual metrics for the measurement of Rub & Buzz, including Listen’s new enhanced Perceptual Rub & Buzz algorithm, and discusses why it can be beneficial to use both conventional and perceptual measurements in tandem.

Full Article

Complete End-of-Line Speaker Test (includes ePRB)

This sequence is an example of the many types of tests that can be performed quickly and simultaneously on a loudspeaker production line. It includes perceptual distortion measurement with the new enhanced Perceptual Rub & Buzz algorithm. A stepped sine sweep (StweepTM) from 20 kHz to 50 Hz is played through the speaker and measured via two channels of the audio interface. A calibrated reference microphone is connected to one of the channels and an impedance reference built into the SC Amp or AmpConnect is connected to the other. A HarmonicTrak™ Analysis step analyzes the recorded waveform from the reference microphone, and outputs Frequency Response, THD, Normalized Rub & Buzz, Perceptual Rub & Buzz, Loose Particle Envelope and Polarity. A Post-Processing step calculates the Ave. Sensitivity from 100 – 10kHz. A second analysis step analyzes the waveform from the impedance reference and outputs a curve of impedance versus frequency. Another Post-Processing step performs a curve fit of the impedance curve and calculates the max impedance (Zmax), precise resonance frequency (f0), and the quality factor (Q) of the resonance peak. All measurements and parameter are tested against limits in Limit steps. All these test parameters can be adjusted accordingly.


Production Testing Seminar China / 产線测试网络研讨会

loudspeaker production lineMay 18th 2022. 10am (China Time) / 2022年5月18日上午10点(中国时间)

In this short seminar, Les Quindipan explores the use of SoundCheck for end-of-line production testing. He discusses typical test configurations and the type of measurements that can be made, how to set pass/fail limits and how to optimize tests for high throughput.

He will also explain how SoundCheck is easily scaled for high volume production testing, with such features as external control via another program and auto-saving data to databases, and how SoundCheck’s capabilities are easily expanded through the use of custom steps to control all types of devices and test fixtures.

This seminar will be of interest to anyone considering a production line implementation of SoundCheck, or curious as to how to transition R&D measurements to fast and effective end-of-line test.

There is no charge for this seminar, but registration is required.

在这个简短的研讨会中,Les Quindipan将 与我们探讨如何使用 SoundCheck 进行生产线末端测试。 他会讨论典型的测试配置和可以进行的测量类型、如何设置通过/失败限制以及如何优化测试以实现高吞吐量。

他还会探讨SoundCheck 如何轻松扩展以进行大批量生产测试,具有通过另一个程序进行外部控制和自动将数据保存到数据库等功能,以及如何通过使用自定义步骤轻松扩展 SoundCheck 的功能来控制所有类型的 设备和测试夹具。

任何考虑在生产线中使用 SoundCheck 的人士,或想知道如何将研发测量转换为快速有效的生产线末端测试的人士都会对此研讨会感兴趣。


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Evaluation of Audio Test Methods and Measurements for End-of-Line Automotive Loudspeaker Quality Control

In order to minimize costly warranty repairs, automotive manufacturers impose tight specifications and a “total quality” requirement on their part suppliers. At the same time, they also require low prices. This makes it important for automotive manufacturers to work with automotive loudspeaker suppliers to define reasonable specifications and tolerances, and to understand both how the loudspeaker manufacturers are testing and also how to implement their own measurements for incoming QC purposes.

Specifying and testing automotive loudspeakers can be tricky since loudspeakers are inherently nonlinear, time variant and affected by their working conditions & environment which can be change dramatically and rapidly in a vehicle. This paper examines the loudspeaker characteristics that can be measured, and discusses common pitfalls and how to avoid them on a loudspeaker production line. Several different audio test methods and measurements for end-of-the-line automotive speaker quality control are evaluated, and the most relevant ones identified. Speed, statistics, and full traceability are also discussed.

Authors: Steve Temme, Listen, Inc. and Viktor Dobos, Harman/Becker Automotive Systems Kft.
Presented at the 142nd AES Convention, Berlin, Germany

Full Paper