Industry & Product News

Beyma Introduces Three New LEX Woofers and More at Prolight+Sound 2019
In party mode to celebrate its 50th anniversary, Spanish professional loudspeaker manufacturer Beyma introduced several new products at this year's Prolight+Sound show in Frankfurt. The debuts include three new high-performance subwoofers that further expand the LEX range, with its unique mix of artistic and optimized mechanical design, a new 14" driver - a new format for the company - and a new 1.4" exit small compression driver .    Read More

Celestion Features Big Red Horn for Axi2050 Axiperiodic Driver at Prolight+Sound 2019
The Big Red Horn was created specifically to work with and optimize the bandwidth performance of Celestion's Axi2050 wideband axiperiodic compression driver. The combo unveiled at the 2019 Prolight+Sound show in Frankfurt served to showcase the company's recently expanded horn design capabilities and highlight its know-how to offer in-depth technical support for horn and waveguide design to OEM partners .    Read More

Yamaha Works with Nexo to Deliver Updated DXRmkII Loudspeakers
At Prolight+Sound 2019, the Yamaha booth was certainly one of the busiest. And one of the reasons for excitement is the updated DXRmkII series of powered loudspeakers. The touring-grade technology of the four-model DXR range delivers class-leading SPLs in a compact, functional design. The updated range features a new, bigger neodymium 1.75" high-frequency driver and retuned DSP, delivering improved audio quality and power from versatile loudspeakers, which are ideal for a wide range of sound reinforcement applications .    Read More

B&C Speakers Debuts DCX464 Coaxial Compression Driver
B&C Speakers' engineers have been working for the last five years on a family of next-generation high-frequency devices. The result, introduced at the 2019 Prolight+Sound show in Frankfurt, is the DCX464, a new time coherent coaxial ring radiator design with a neodymium magnet assembly, which the company believes will open new horizons for the professional audio industry. The 1.4" horn throat diameter of the DCX464 delivers a complete response from 300 to 18,000 Hz thanks to a patent-pending design that combines both diaphragms .    Read More

L-Acoustics Introduces New ARCS Family of Scalable Rental Solutions with Five New References  
During Prolight+Sound 2019, L-Acoustics introduced five new references in its ARCS family, including the A15 Focus, A15 Wide, A10 Focus, A10 Wide, and KS21 Sub systems, designed for audiences from 50 to 5,000 in an approachable, compact format that offers greater versatility and ease of use. With the launch of the new ARCS product range, L-Acoustics introduces a new charter agreement offering rental partners meeting the ARCS standard system requirements the opportunity to join the official L-Acoustics rental network .    Read More

Brüel & Kjær Introduces New B&K 2245 Sound Level Meter
Sound and vibration specialist Brüel & Kjær has released the new B&K 2245 Class 1 sound level meter, providing a complete solution for basic noise measurements, while combining functionality, ease-of-use and versatility. The latest in Brüel & Kjær's range of iconic sound level meters was designed to instill confidence in professionals whose work involves noise measurement tasks, providing the reliability associated with the brand, while offering the flexibility to work in combination with dedicated mobile apps .    Read More

Powersoft Shows New Amplifier and Innovative OEM Components at Prolight+Sound 2019
Powersoft returned to Messe Frankfurt in force for Prolight+Sound 2019 with a full suite of industry audio solutions, including the new X4L, a four-channel amplifier specifically designed for peak voltages and to feed the most power hungry arrays and subwoofers. On the OEM components range, Powersoft introduced the LOTO DSP 1-2 in / 4 out Advanced DSP board; the DSP-Lite ETH 1-2 in / 3 out DSP interface for LiteMod, MiniMod, and DigiMod amp modules; and an update for its Snapshot Selector mobile app .    Read More

The Search for Ultimate Sound: Sonarworks Launches User-Driven Research Project for Sonic Personalization
Sonarworks, the European sound calibration software developers, have just announced the launch of a public research project designed to fine-tune the calibration of their award-winning apps for individual listener preference. The Sound Preference Research Project, which is currently underway globally, enables users to audition music samples with different sound settings in a simple A/B assessment to choose the sound they most prefer .   Read More

Guest Editorial


Rockets to Recordings

It's surprising how often unrelated events give rise to innovations that shape the future. "If World War II hadn't happened, would we have seen the development of some of the world's greatest microphones?"

It's interesting to note that the 16-bit/44 Hz format of the humble CD was set in 1980 so that recording sessions could be digitally made using what was one of the most successful portable video recorder formats of all time - the Sony U-Matic video recorder, which has been around since the early 1970s. If the CD had waited until 1986 when the Sony U-Matic SP was produced, which had much better performance, would we now have better quality CDs? However, it's not just audio CDs that have their roots in a different technology that was around at the time.

A V-2 Rocket on a Meillerwagen transporter

In the early days of radio and electrical sound recording, carbon microphones were used, but their quality was dreadful. In Germany, Georg Neumann considered that a far better microphone could be produced based on a capacitive transducer, but these condenser microphones could only be manufactured under laboratory conditions. So Neumann set about developing the technology to suit commercial manufacture and established his own company in 1928 to produce the first-ever mass-produced condenser microphone, the CMV3. This was far superior to carbon microphones and gained recognition under the nickname of the "Neumann Bottle." It had a selection of exchangeable capsule heads with different polar patterns for use in different situations, but it wasn't exactly compact, measuring about 9 cm in diameter, 40 cm high, and weighing in at nearly 3 kg (approximately 6.6 lbs).

Frank Sinatra with a U47 microphone
Don't mention the war!
Right up until the end of World War II, the CMV3's design remained virtually unchanged and this microphone was the standard for studio use. After the war, the damage to German infrastructure was so severe that no nationwide electricity supply existed. Instead, many provisional mains electricity supplies were put in place - some AC and some DC. So, as part of post-war reconstruction, domestic radios were required that could operate on DC. This was quite an unusual requirement because sets running on DC supplies can't use mains transformers. 

To satisfy this demand, German tube manufacturers, in particular Telefunken, developed tubes with high filament voltages that could be run directly from the mains supply. One such tube was the VF14, which had a high voltage (55 V) heater and could work at radio frequencies as well as audio frequencies, and it soon became the workhorse tube of the time. Since two-tube radio-sets were commonplace and 110 V AC and DC were the mains supplies in Germany then, two VF14s' filaments could be powered by wiring them directly across the mains in series (I'm sure the Health and Safety Executive would have something to say about that nowadays!). Anyway, the VF14 was mass-produced by Telefunken and it found applications in everything from military field radios to the Vergeltungswaffen Zwei (aka V-2 Rocket or Retaliation Weapon 2).

So how did all this affect microphone development? Well, the new German broadcast stations after the war had the same issue as civilians. Faced with a 110 VDC mains supply, Berliner Rundfunk (Radio Berlin) asked Neumann to supply them with microphones that could be used without a transformer power supply. Neumann solved this problem in exactly the same way as the radio designers and opted to use the VF14. So in 1949, the Neumann company launched the microphone that has probably had the greatest influence on the development of modern studio microphone technology - the U47. Its impact, especially in America, was such that the dominance of RCA's ribbon microphone was eclipsed by it as the studio standard. A particular feature of the U47 was that its characteristics were adjustable and could be tweaked to suit the requirements of the studio or, indeed, the artist. The U47 was a firm favorite among recording artists, such as Frank Sinatra, because its response characteristics particularly suited the human voice, and it is still very much in use today. A development of this microphone, the U48, was also produced and this allowed switching between different polar patterns, such cardioid and figure-eight directional characteristics.

A Neumann U47 microphone

So, why was the quality of the signal from these microphones so high and, in many ways, ahead of their time? This may be due in part to the fact that a problem for Neumann in developing the U47 was that the requirements are very different for the tube in the head amplifier of a broadcast microphone and for a tube in the RF front-end of a radio. While the VF14 tube worked consistently in the latter, only a few examples worked in the former and passed Neumann's stringent testing processes. Neumann's solution was to set up an arrangement with Telefunken so that when they took delivery of a batch of VF14s, they only selected the ones that were suitable for use with microphones. Those that passed the Neumann test procedure were marked with an "M" on the side of the steel can (for Microphone). However, at least two-thirds of the tubes off the production-line were rejected by Neumann for inadequate performance. So, every tube was hand-picked for the job and that probably accounts for the very high standard.

Neumann went on to produce other legendary studio microphones, including "dummy head" microphones for binaural recording. However, a question still remains - if it hadn't been for the War, would one of the greatest microphones of all time been invented? I think perhaps not.

From The Vault
Constant Current for Tube Heaters. Extend the Life of Your Amplifier's Vacuum Tubes
By  Bill Reeve

In this article, Bill Reeve explains how to drive tube heaters with a constant current to lengthen the life of your vacuum tubes. As he explains, obviously, the best way to extend your amplifier's vacuum tube life is to never turn it on. Some would say that the second best thing you can do is to never turn it off. The third and fourth options may be to gently turn on the tube heaters and not leave the B+ voltage on when the heater voltages are off. "I don't implement the first or second suggestions. However, I do drive the tube heaters with a constant current (rather than constant voltage) whenever I can to further those third and fourth goals," he states. This article was originally published in audioXpress, May 2014 .   Read the Article Now Available Here

Voice  Coil Focus
New Materials for Earphones and Headphones
By Mike Klasco and Nora Wong (Menlo Scientific, Ltd.)
For the January 2019 edition of Voice Coil magazine, Mike Klasco and Nora Wong have compiled a special Focus article on New Materials for Earphones and Headphones. For those looking to differentiate their new products, the two Menlo Scientific consultants provide a unique and valuable perspective on multiple possibilities and designs for drivers, materials for assemblies and enclosures, choices for headbands and ear cushions, signal processing, and even cables. This article was originally published in Voice Coil, January 2019 .   Check it out here!

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