Audio Precision tackles rub & buzz detection
- Details
New features include: rub & buzz – Previously available in APx software, this method uses high-pass tracking filters to remove the fundamental signal and detect defects as excursions in the residual waveform’s crest factor or peak ratio; SoneTrac – A Bose-developed improvement to the Rub & Buzz, this method filters the residual signal and ratios it to the RMS of the total signal to reduce the noisiness of the measurement result; High-Order Harmonic Distortion - a classic method for rub & buzz detection, HOHD uses the THD (Total Harmonic Distortion) ratio but only of harmonics above the 10th, 10-35, 20-200, etc., which is a simple way to account for frequency masking effects.
To support the addition of the HOHD and Rub & Buzz Loudness measurements, AP is introducing the Fast Sweep signal with APx500 release version 6.1. Advantages of the Fast Sweep are the lack of transient ripples at low or high frequencies, the ability to sweep from low-to-high or high-to-low frequency, the support for measuring harmonics above the 20th, and precise control of the number of discrete points used in measurements.
APx500 release version 6.1 now allows users to switch instantly between IEC and IEEE THD calculation modes for harmonic distortion results. Version 6.1 also adds the ability to normalise harmonic distortion results, addressing common measurement artifacts that occur when testing loudspeakers. Users can now also save all acquired waveform, impulse response, or cross-correlations results to .wav files, and this function can be included as a sequence step in automated measurement sequences.
"While version 6.1 is officially a minor release, and thus a free upgrade to any analyser licensed for version 6.0, it delivers significant, new capabilities, especially for those involved in the design, manufacture, and test of speaker drivers and any product incorporating them," said Daniel Knighten, Audio Precision general manager. "Simply put, APx audio measurement software now offers the broadest set of rub & buzz defect detection methodologies available."
Software upgrades are available for owners of Legacy APx analyzers, with options for upgrading from v4.x (or earlier) to v5.0, from v4.x to 6.0, and v5.0 to v6.0.
