Converged audio testing for integrated audio products

October 02, 2013 // By Graham Prophet
A suite of electro-acoustic measurements has been added to the APx platform for end-to-end testing of Integrated Audio Products, from electronic input to acoustic output

Audio Precision's software release expands the features of the electro-acoustic test suite for APx audio analysers. APx v3.4 adds Thiele/Small parameters, Complex Impedance and Loudspeaker Production Test to the APx platform, 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 an 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. AP implements analogue audio testing with ultra low distortion, wide input and output ranges and high accuracy measurements, while APx I/O options provide native connectivity for a wide range of digital formats including Bluetooth, HDMI, PDM, and Digital Serial.

“Soundcard-based analysers are not designed for testing electronics with input voltage typically not exceeding 10V and inappropriate input and output impedances. In addition, having to use different instruments for different domains is inefficient and expensive,” says Tom Williams, VP of sales and marketing at Audio Precision, “With APx, engineers can use a single analyser with a single automated project to test analogue circuitry, Bluetooth connectivity and driver electro-mechanical characteristics like impedance, Thiele-Small and rub and buzz. The result will be a single consistent data set ready to share between collaborators or an integrated report from the most reliable and trusted name in audio test.”

R&D engineers working on integrated audio products must be able to obtain reliable results from each part of the signal chain, from analogue inputs to digitally processed compensation to power amplifiers and loudspeakers. The APx electro-acoustic suite offers 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