Audio Precision has released a software utility that automates the testing of headphones and earphones used with portable audio players.
The utility, which runs exclusively on Audio Precision’s APx Series analysers, automates the measurements required by British Standard/European Norm 50332 Parts 1 and 2. An accompanying AP Technote (Measuring the Sound Pressure Level of Portable Audio Player Headphones with APx Audio Analysers) describes in detail how to use the utility to conduct the tests specified in the standard.
The standard requires a special Program Simulation Noise test signal and a test fixture known as a Head and Torso Simulator (Hats). Sound pressure levels measured in the ear simulators of the Hats must be corrected to free field response and then A-weighted and averaged. ‘The calculations needed to derive the results required by the standard are too complex for the typical user to do manually,’ says Joe Begin, head of AP Technical Support. ‘And the Program Simulation Noise signal would also be a challenge for customers. We used Matlab to create the signal in the digital domain. The utility bundles that in and takes care of all the necessary calculations.’
APx is a next-generation platform with several models including the high-performance APx525, multichannel APx585 and low-cost APx515 optimised for production test. All APx models use the same software and feature one-click automation, and automated reporting.
According to Audio Precision distributor Man Li of AP Technology in China, the new utility and its accompanying Technote will save manufacturers hundreds of hours of development time and ‘reduce the possibility of costly mistakes in their testing programmes’.
More: http://ap.com
