Current Source Crossover Filters

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.

Measurement microphones are a special class of microphones, ranging from laboratory precision instruments to products used for fine tuning sound systems in commercial or residential settings. Measurement microphone pricing varies greatly from $10 to 4,000. The quality differs immensely and there are many choices in between. This article was published originally in Voice Coil October 2012.

Headphones with built-in electronics, such as digital headphones (including Bluetooth and USB), and noise-canceling headphones are harder to test because the electronics and transducers need to be tested together as a complete system. This Part 2 article discusses those tests. Article originally published in Voice Coil April 2012.