Audio Precision Software Enhances Loudspeaker Test
October 18, 2013. Audio Precision has announced a new software release that expands the features of the electro-acoustic test suite for APx audio analyzers. APx v3.4 adds Thiele/Small parameters, complex impedance, and loudspeaker production test to the APx platform.
This expanded electro-acoustic capability makes APx audio analyzers suitable for designing and testing integrated audio products that incorporate electronics, digital signal processing, and loudspeakers.
In addition to the new measurements, the APx electro-acoustic suite includes capabilities for measuring energy-time curve (for quasi-anechoic measurements), impulse response, frequency response, relative level, phase, distortion product ratio, distortion product level, rub and buzz, and modulated noise (for air leak detection). Output options include waterfall charts and polar plots via APx utilities.
Converged Audio Test covers all aspects of today’s integrated audio products. APx I/O options provide native connectivity for a range of digital formats including Bluetooth, HDMI, PDM, and Digital Serial. With the expansion of the APx electro-acoustic test suite, integrated audio products can be tested in every domain, at every step from R&D to Production.
“Soundcard-based analyzers are not designed for testing electronics with input voltage typically not exceeding 10 V and inappropriate input and output impedances. In addition, having to use different instruments for different domains is inefficient and expensive,” said Tom Williams, VP of sales and marketing at Audio Precision, “With APx, engineers can use a single analyzer with a single automated project to test analog circuitry, Bluetooth connectivity and driver electro-mechanical characteristics like impedance, Thiele-Small, and rub and buzz.”
Converged Audio Test in R&D and Production
R&D engineers working on integrated audio products must be able to obtain reliable results from each part of the signal chain, from analog inputs to digitally processed compensation to power amplifiers and loudspeakers. The complete APx electro-acoustic suite is suitable for these tasks, offering flexibility and reporting capacity. The full range of Thiele/Small parameters may be obtained using added mass, known volume, or known mass methods.
For high speed production test, impedance magnitude and phase plus a limited set of Thiele-Small parameters are calculated (along with frequency response, relative level, phase, distortion product ratio, distortion product level, and rub and buzz) from a single log sweep.
Because APx is a unified platform, R&D can define tests and acceptable ranges of results, sending this information directly to the factory for complete quality control of the manufacturing process.
The new electro-acoustic measurements are enabled through two new software options. Both options are available concurrent with the APx500 v3.4 release scheduled for Oct 4, 2013.
An APx analyzer is required to run the measurements. All models support the below options:
- APX-SW-SPK-RD (for R&D): Impedance magnitude, impedance phase, impedance real, impedance imaginary, complete Thiele-Small parameters, energy time curve, impulse response, frequency response, relative level, phase, distortion product ratio, distortion product level, rub and buzz, and modulated noise. Includes all measurements in the Loudspeaker Production test measurement detailed below and polar plots and waterfall graph utilities. Price is $1500.
- APX-SW-SPK-PT (for production test): Frequency response, relative level, phase, distortion product ratio, distortion product level, rub and buzz, impedance magnitude, impedance phase, Limited Thiele-Small parameters, and modulated noise. Price is $750.