Entries by Zarina

SoundCheck ONE

Author: Vance Dickason. Reprinted from the October 2010 issue of Voice Coil. VoiceCoil Editor Vance Dickason offers this user report of SoundCheck® ONE – the low cost production line test system from Listen. Full Article

ESCORT: The Listen Guide to Audio Troubleshooting

Author: Steve Temme Audio test troubleshooting comes down to 5 things: Environment, Setup, Calibration, Organization, Range and Technique. In this article we discuss each of these areas of potential problems and provide suggestions for troubleshooting any audio testing setup, regardless of application. We also provide general hints and tips to improve your audio testing configuration. […]

Ported Loudspeaker Splice Test Sequence

This loudspeaker splice sequence measures the anechoic response of a loudspeaker in an ordinary room using both a near field and time-windowed, far field measurement “spliced” together to cover the full bandwidth of the loudspeaker’s response from 20 to 40 kHz. It can accommodate ported as well as sealed loudspeakers. First, the near field frequency […]

Evolution of Time-Frequency Analysis Methods and their Practical Applications

Time-Frequency analysis has been in use for more than 20 years and many different Time-Frequency distributions have been developed. Four in particular, Short Time Fourier Transform, Cumulative Spectral Decay, Wavelet and Wigner-Ville have gained popularity and firmly established themselves as useful measurement tools. This paper compares these four popular transforms, explains their trade-offs and discusses […]

Challenges of MP3 Player Testing

MP3 player audio performance is discussed including measurements of frequency response, phase response, crosstalk, distortion, sampling rate errors, jitter, and maximum sound pressure level with headphones. In order to make these measurements, several measurement techniques and algorithms are presented to overcome some of the challenges of testing MP3 players. We discuss test equipment requirements, selection […]

The Challenges of MP3 Player Testing

Author: Steve Temme MP3 players have been the ‘must-have’ electronic gadget for the past few years. Over 10 million players were sold in 2005, and this is predicted to rise to more than double this by 2010. But how can manufacturers carry out QA tests on the production line, ensure excellent sound quality and demonstrate […]

A New Method for Measuring Distortion using a Multitone Stimulus and Non-Coherence

A new approach for measuring distortion based on dual-channel analysis of non-coherence between a stimulus and response is presented. This method is easy to implement, provides a continuous distortion curve against frequency, and can be used with a multitone stimulus, noise, or even music. Multitone is a desirable test signal for fast frequency response measurements […]

Higher Order Harmonic Signature Analysis for Loudspeaker Defect Detection

Loudspeaker assembly faults, such as a rubbing voice coil, bent frame, loose spider, etc., have traditionally been detected using experienced human listeners at the end of a production line. Previous attempts to develop production measurement systems for on-line testing typically analyze only low-order harmonics for the primary purpose of measuring total harmonic distortion (THD), and […]

Enhancements for Loose Particle Detection

During loudspeaker production, particles may become trapped in the loudspeaker motor and voice coil vicinity, resulting in a distinctive defect that is easily heard, but difficult to detect by traditional test and measurements. We found that a Sine Sweep Stimulus followed by a High Pass Filter and RMS Envelope Analysis efficiently detected Loose Particles and […]