Why Power Tubes Arc

Tube arcing is not necessarily a result of a "bad" tube or a "bad" design. It is far more likely the result of using the tube longer than you should for the application you’re using it. This interesting article, published in audioXpress, November 2004, remains a great read. At the time it also originated a response from Eric Barbour and Ed. T. Dell regarding their experience with cathode stripping.

This patent describes, a compact high-fidelity sound reproduction system achieving high efficiency, low distortion, wide bandwidth, and extended low-frequency reach, and which can be used as a sub-bass woofer, bass woofer, mid-bass woofer, and mid-range speaker for residential or commercial large venue applications. The system includes a dynamic driver driven bass horn, a looped resonator duct (ring geometry), which can be folded, and an adjustable feedback duct allowing sound characteristics to be tailored. This article was originally published in Voice Coil, April 2016.

Knowles announced the availability of a new development kit for true wireless stereo (TWS) earbuds, centered on the capabilities of its AISonic family of audio edge-AI processors and expanded by key partnerships in voice and audio processing algorithms for TWS products. This article details the opportunities for TWS development and helping manufacturers to differentiate their newest designs. This article was originally published in audioXpress, January 2022.

audioXpress March 2022 Test and Measurement issue addresses the latest tools and solutions meeting real-world challenges in audio. This year's extensive Market Update report, offers a complete overview of all the audio test and measurement products and solutions released during the past 12 months. One of the major highlights was Echo Test + Measurement, with its modular, and highly cost-effective range of audio test interface solutions.

This review discusses an invention that promises to successfully process an audio signal to focus an acoustic signal by an arrangement of a plurality of loudspeakers, using a frequency analyzer, a signal processor, and a signal output interface. The frequency analyzer is configured to determine a fundamental frequency and the signal processor configured to adapt an overtone of the fundamental frequency. An approach that can work quite well, even though there are well-known drawbacks that the patent intends to resolve.

In this article, the authors share their research on new requirements for the measurement of in-wall installation speakers. The directional characteristics are an especially important factor, because the direction in which a loudspeaker emits sound highly affects the interaction with the listening room and the listening experience. The authors' research addressed the requirement using holographic directivity to address the way the directional characteristics interact with the listening room. This article was originally published in audioXpress, December 2021.

In this exclusive article for audioXpress, Lars-Johan Brännmark (Chief Scientist, Dirac Research AB) describes an approach to the challenge of applying DSP room correction to complex multichannel setups, intended for immersive audio reproduction. Instead of one filter applied to a single channel, he proposes a solution where all speakers work to optimize the reproduction of each input channel in an optimal way. This article was originally published in audioXpress, December 2021.

This article, written by Al Clark (CEO, Danville Signal Processing), tells the story of his company’s R&D journey into the development of the dspNexus DSP Audio Processor. An interesting perspective about how the author’s experience led him to maximize the possibilities of digital audio, resulting in successfully bringing to market a dedicated DSP audio processor that could be used as a control center, a preamplifier, and a DSP engine for powered loudspeaker applications. This article was originally published in audioXpress, November 2021.

This review discusses a patent that applies to speakers designed for new immersive audio formats in home applications and Dolby Atmos, in particular. Not surprisingly, the patent was awarded to Dolby Laboratories Licensing Corp. As the patent was granted, Voice Coil provided an extensive and informative review - recommended reading for anyone considering entering this important home-theater market segment. This article was originally published in Voice Coil, February 2016.

Stuart Yaniger shares his impressions and measurements of the Phonitor One d Headphone Amplifier System, designed by SPL of Germany. This product uses the company’s unique 120V circuitry, and also features an acclaimed AKM premium USB DAC and balanced stereo line output, effectively enabling it to function as a combination DAC and preamp. An interesting design also because of its Phonitor Matrix, a unique feature designed to electronically create a crosstalk signal and generate something similar to the effect of acoustic crosstalk around our head when listening through headphones. This article was originally published in audioXpress, November 2021.