Audio Testing With Noise

Usually we think of noise as a signal to be eliminated, or at least reduced, in any audio system. However, noise can be a very useful test signal because it is inherently broadband, which is faster and perhaps more accurate than spot or swept frequency testing. Article originally published by Voice Coil, December 2010

In this article, author Pete Millett explores the different types of power transformers, and why you might choose to use each type in audio equipment. The article addresses issues with low-frequency (50–60Hz) line transformers, but many of the same issues apply to audio-frequency transformers as well.

All-pass filters are perhaps one of the most overlooked and misunderstood tools for the general audio practitioner. Much has been written about their use to yield more linear phase response through the majority of a loudspeaker’s passband. They can also be used to optimize the directivity and magnitude response of a loudspeaker system. Perhaps we should first look at exactly what an all-pass filter is.

The specification of a loudspeaker’s sensitivity is probably one of the most common, yet perhaps one of the most misunderstood. In the past, and still today, it is common to see the magnitude response of a loudspeaker system reduced to a single number as a sensitivity rating. Article originally published by Voice Coil, April 2010.

Horns are often used in loudspeaker systems for a variety of reasons. One may be to provide increased acoustical loading to the driver attached to the horn. This helps to increase the sensitivity/efficiency. Another may be to provide some control over the radiation pattern of the driver attached to the horn. Article originally published by Voice Coil, November 2010.

An excellent article from the audioXpress archive, published originally in February 2003, James Moriyasu offers a complete study examining speaker cabinet edge diffraction and what we can do to reduce it. The author attempts to measure the extent of acoustic edge diffraction and test possible solutions for reducing its levels

Do you plan to work with transmission line speakers? Before you begin, consider the effects of stuffing on your transmission line speakers. In this article, you'll learn about the effects, as well as a test setup with mics in a cardboard tube, a preamp, scope, sweep/function generator, and mini receiver.

Which sounds better — a tube or solid-state amp? The "Great Debate" has been going on for decades. Now it's time to put the debate to rest. In audioXpress, November 2012, Richard Honeycutt's published this article exploring how to detect audio amplifiers’s differences in sound and the need for a correct subjective evaluation process of components and systems.

If you're a serious audio electronics DIYer, you likely have a bench-top supply in your workspace. So, how can you determine the stability of your lab or bench-top supply? You can get a good impression of the stability of a power supply under various conditions by loading the output dynamically.

Choosing the correct speaker enclosure can be the difference between decent sound and excellent sound. As Mike Klasco and Steve Tatarunis explain in the September 2012 issue of audioXpress, “No matter how much effort was spent on the drivers’ design, …