Sources 101: Audio Current Regulator Tests for High Performance - Full Article

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.

In this article published originally by audioXpress in March 2005, Nelson Pass offers a series of tips about designing filter networks for both voltage and current sources. Nelson Pass provides filter examples that can be used equally well with a voltage or current source.

It was recognized early on that the speakers benefited from having separate low-frequency and high-frequency drivers, each optimized for its own frequency range. Consequently, names were needed to easily identify the various speakers in a cabinet. This article was originally published in Voice Coil, January 2012.

In this tutorial Charlie Hughes addresses the question of “How do I align a subwoofer with a full-range loudspeaker system?”. He answers the problem by addressing the three main issues of crossover frequencies, relative output level and delay. This article was originally published in Voice Coil November 2011.

What can you do to ensure the best possible sound from your system? According to Nelson Pass, the “sweet spot” concept is generally regarded as “that happy balance of conditions that elicits the best possible sound,” including the interiors of the components themselves. This article was originally published by audioXpress, January 2010.

In this article, the author addresses possible scenarios when measuring loudspeaker input impedance at drive levels closer to those used in actual operation, including problematic examples with vented loudspeaker enclosures and constant voltage distributed system transformers. This article was originally published in Voice Coil, February 2011.

Inspired by a presentation by Bill Whitlock, President of Jensen Transformers - a three-hour tutorial seminar titled “Audio System Grounding and Shielding: An Overview” - during the Audio Engineering Society convention in New York in 2007, Gary Galo decided to investigate a little more into the subject and do some reviews of the mentioned equipment.

These days everyone is getting into the headphone business. This 10-point “cheat sheet” provides a place to start product definition development efforts. This article was originally published in Voice Coil, July 2013.

When performing electroacoustical response measurements, an important practical consideration is the reduction of uncorrelated background noise. Synchronous averaging (i.e., “complex averaging,” “time domain averaging,” or “vector averaging”) is a technique originally developed to analyze the vibration signature or rotating machines and gearboxes. It can be used to improve the S/N ratio measurement. This article was published originally in Voice Coil November 2012.