The Internal Life of Vacuum Tubes

A few years ago, Jan Didden designed a high-voltage delay unit and shared its details in a 2019 audioXpress article. Many people built it and like it, but others said that it would be totally unnecessary. As so often happens in audio, arguments pro and con raged without a clear resolution. So Didden thought this was something he needed to get his head around. He found several sources, which he thought were credible, and this article is the result of his investigations, fed by those sources. This article was originally published in audioXpress, August 2020.

Mike Klasco (Menlo Scientific) writes about "a very cool" concept from Soundmatters, the company's UPstage speaker design, a new speaker product category and the next trend from the people that invented the soundbar. The sophisticated engineering implemented by soundmatters into the UpStage compact high-performance audio system was also the launch platform for BDNC's high-power, flat glass woofer that uses a 0.2 mm glass diaphragm. This article also explains what manufacturers need to know about the BDNC glass diaphragm, high-excursion, ultra-low profile woofer technology.

Imagine a new class of speaker diaphragm position sensors that enable audio engineers to reduce distortion and extend bass response from studio monitors, soundbars, smart speakers, and even smartphone microspeakers. With the precision of laser displacement instrumentation, this sensor is located between a stationary component of the speaker and an appropriate moving part to provide an error correction reference signal back to the amplifier. Well, that sensor has already been developed. ​This article was originally published in The Audio Voice weekly email newsletter.

This article by Hans W. Gierlich and Jan Reimes - two top experts in communication technologies from HEAD acoustics GmbH - details the expanded effort for understanding speech under noisy conditions, and addresses a new approach recently introduced by HEAD acoustics, resulting in a new model that can be used to test active noise cancellation (ANC) performance in complex scenarios where the system needs to distinguish between speech signals as part of the background noise and speech signals directed toward the users of these devices. This article was originally published in audioXpress, April 2020.

Voice processing and recognition leading to the development of voice-based personal assistants is one of the decade’s greatest achievements and provides a unique opportunity for the audio industry. Leveraging those sophisticated technologies now available to the consumer electronics industry makes the investment on new designs much more exciting. In this article, Mike Klasco provides an introduction to the voice capture, signal processing and voice recognition challenges. This article was originally published in audioXpress, December 2018.

Voice-enabled devices are quickly becoming commonplace in nearly every region and for every consumer demographic. Whether making cloud-connected or offline products, OEMs need to understand what’s driving this demand for voice. Unlike some new product features, adding a voice interface requires product architects to make a number of highly-impactful, interconnected design decisions. Development teams don’t have it easy either, as integrating microphones in a product introduces another layer of complexity.

Mike Klasco and Steve Tatarunis wrote a series of articles under the header Parts is Parts where they explore loudspeaker drivers, how they work, and all the different parts and components. In this article, the two audio industry experts expand on the historical evolution of tweeter design. After discussing the cone tweeter, and introducing the common dome tweeter, the article explore dome tweeter variations and introduces the balanced drive tweeter. This article was originally published in audioXpress, February 2013.

For several years, Mike Klasco and Steve Tatarunis wrote a series of articles under the header Parts is Parts where they have explored loudspeaker drivers, how they work, and all the different parts and components. In this specific article, the two audio industry experts provide an excellent introduction to high frequency drivers, revisiting some key historical designs. This article was originally published in audioXpress, January 2013.

This article discusses an approach for time-efficient testing of loudspeaker suspension parts, close to their final operating conditions. It refers to the Linear Suspension Test set (LST Lite), a hardware and software add-on for the Klippel QC loudspeaker end-of-line testing system. The system may be applied to 100% of the parts or to a random sample. This article was originally published in Voice Coil, December 2012 (with some updates introduced from 2019 documents).

A new generation of effective and powerful speaker protection technology, using literally all the capabilities and power of pro sound rackmount loudspeaker management processors, is now being designed into mobile audio products that use very small loudspeakers. The implications are that mobile consumer electronics are going to play louder and sound better than ever. But to optimize speakers this way, we need to understand what causes loudspeakers to fail. This article was published originally in audioXpress, August 2013.