Pollux, a Raspberry-Pi-based universal intercom front end

What do ships, factories and security services have in common? Several different and incompatible communication systems to control and secure one site. Indeed, VHF radios, telephones, intercom systems and more are all used together to communicate with the different services, rooms and departments in a building or on a site. Pollux provides a single front-end for all these communication systems.

DJs and fans of light shows are devotees of USB/DMX512 converters to control their projectors from their laptop PCs. Unfortunately, those found in the commercial world are often not (well) isolated from the mains voltage. Here, on the other hand, an isolated DC/DC converter powers the isolated RS 485 transceiver. Like any DMX device worth of the name, this new converter has an XLR socket.

Taking full advantage of the Raspberry Pi’s open architecture, you can customise and program the NanoSound HiFi DAC. With the Volumio software or any other player software and the Infrared Remote Control, NanoSound gives you the best audio performance and experience you can expect from such an audio player.

Invented about one hundred years ago the Theremin remains a popular electronic musical instrument. Commercially available high-quality designs are expensive making DIY projects extra appealing. However, it is not so easy to come up with a reproducible all-analogue circuit. Can you help?

Besides small SUVs, crossovers are also filters used in audio to divide the audio signal into two or more frequency bands. A typical example is a home cinema audio system where a subwoofer handles the low bass frequencies while other speakers handle the mid and high frequencies. Here is an active 3-way crossover design with three or four stages based on state-variable filters.

The current surge demanded at power-on by a circuit presenting a large capacitive load to the power supply can destroy the power supply or trigger its short circuit protection. In both cases the result is the same: the circuit will not start. A solution is to insert a soft-start circuit to control the inrush current. This soft-start circuit with many additional features was designed to protect an audio amplifier and you can build it too.

This new book published by Elektor helps us to understand the variables and choices entailed in proper acoustic design for performance. The level of presentation in the book Acoustics in Performance by Richard A. Honeycutt is comfortable and straightforward without being simplistic. If correct acoustical principles are incorporated into the design, renovation, and maintenance of performance venues, good acoustics will be the result.

Vision Research has added the Phantom v2640 model to its range of products. This is probably the world's fastest video camera, able to record up to 11,750 fps in color and HD or 25,030 fps in monochrome with a maximum resolution of 2,048 x 1,952 pixels...

The book succeeds in quantifying and qualifying many sensations associated with hearing in large rooms and even larger buildings, specifically concert halls and places of worship as the author Honeycutt calls them. Every chapter in the book first describes the ways in which the communication problem posed by poor acoustics is worded by the ‘parties’ involved: like the vocalist bothered by audience babble, the audience bothered by echoes and HVAC hum, and the hapless sound technician finding that his carefully wrought mixing console settings are useless once the hall is full of people wearing coats. Honeycutt’s book addresses all these aspects and more.

STMicroelectronics together with the audio company USound has developed the first MEMs micro-loudspeaker based on silicon. Samples are currently being delivered to the first customers and the speakers are being showcased at CES 2018 in Las Vegas...