Acoustic Simulation of Audio Devices with Actran Software

Loudspeaker design is not a trivial exercise, and as a result, high-performance acoustic simulation software is essential to get accurate predictions that help an engineer develop superior products. Demand for simulations at early design stages are increasing because cost and timing constraints make it impossible to prototype and test every design idea and much can be learned from simulation results, which cannot be obtained in the test chamber. Actran, MSC Software Company’s acoustic simulation solution, based on Finite Element Analysis (FEA) technology, provides predictive simulation capabilities to assess the vibro-acoustic performance of audio devices, which include speakers and microphones.

audioXpress December 2015 included another great Practical Test & Measurement article on “Testing Audio ADCs and DACs,” written by David Mathew from Audio Precision. As he explains, the articles discuses methods used to procure high-quality results by correctly evaluating the critical AD and DA stages, with conventional and more evolved measurements used in audio tests. The article also includes an interesting side-text detailing how Audio Precision found an ideal test case for the APx555 analyzer. Full article now available online.

Dan Foley discusses how audible distortion can be difficult to measure and explores the instrumentation noise floor’s impact on what can be measured. As he explains, this is an overlooked contributor for the reason we are not able to measure a particular audible “distortion,” especially with low sound pressure level (SPL) signals. This article was originally published in audioXpress, March 2016 - Focus on Test & Measurement Special issue.

Here’s the final section in our series on parts reliability, how to choose them and how to estimate their life expectancy. In the third part of this article, the author continues to examine electronic components, and discusses what we can do about reliability. This article series was published in audioXpress, from November 2001 to January 2002.

Everything you need to know about how parts function, and how to select and maintain them. In the second part of this article, the author continues to examine electronic circuits with a look at some common circuit components, like resistors, semiconductors, diodes, small signal transistors, power Semiconductors, and microelectronics. This article series was published in audioXpress, from November 2001 to January 2002.

Everything you need to know about how parts function, and how to select and maintain them. In the first part of this article, the author discusses damaging effects of high temperatures, why things fail, MTBF, component tolerances and the effects of shock and vibration. This article series was published in audioXpress, from November 2001 to January 2002.

Recently, there has been increased demand for loudspeaker 3-D directivity measurements both in the near- and far-fields for different applications. New holographic near-field scanning techniques provide new ways to determine the sound pressure at any point in the 3-D sound field. This article was originally published in Voice Coil, May 2015.

Switched mode circuits are increasingly being used today in electronic devices. Due to the rapid switching speeds found in these switched mode circuits, the probability of high frequency ground connection interferences is also becoming more prevalent. A correctly specified and placed ground choke, using Schurter’s range of power IEC modules with line filter and optional voltage selector (step switch), offers a simple and safe solution.

In April and May 2007, audioXpress published a two-part article by Walter G. (Walt) Jung, noted designer and author of the IC Op Amp Cookbook and IC Op Amp Applications book series. In this article - still being referenced to date - the author discusses audio current regulator circuits and their performance with regard to power-supply-related noise. Read the two-parts plus addendum letters.

In this fascinating article, published in audioXpress, October 2004, Nelson Pass investigates loudspeaker performance when driven by a current source amp. This extensive research shows what Pass and Kent English found with a variety of full-range sensitive loudspeaker drivers when they drove them with an active current source and played with parallel networks to shape the response to their liking.