INDUSTRY & PRODUCT NEWS

AfterShokz Introduces Bluetooth Bone Conduction Headphones Trekz Titanium on Indiegogo

AfterShokz launched its new Trekz titanium headphones on Indiegogo, a wireless, bone-conduction headphone perfect for runners, hikers, and cyclists. The design enables users to listen to music while keeping their ear canals open and AfterShokz says its PremiumPitch+ technology guarantees they won't compromise on sound. Read More

World's First Wireless Music Sharing Fitness Headphone with Walkie-Talkie Mode

SOUL Electronics is promoting its Combat+ Sync fitness headphones, combining sound quality, comfort, and durability for the most intense workout sessions with innovative walkie-talkie functionality and wireless music sharing via Bluetooth. The project was launched on Kickstarter. Read More

The Audio Winners of the European Imaging and Sound Association 2015-2016 Awards

Just before the annual IFA consumer electronics show in Berlin, the European Imaging and Sound Association (EISA) Awards, featuring more than 20 audio categories have been announced. Winners for 2015-2016 include Hi-Fi, mobile, home-theater, and in-car products. Read More

Using Headphones During Exercise Helps Athletes Stay Focused

A new study, conducted by a market research institute on behalf of Sennheiser, found that more than half of athletes who engage in sports at least once or twice a month say their headphones help them stay focused, creating a personal space. About 27% say they do so to block outside noise. Read More

Audinate Enhances Dante Ultimo Capabilities with New Channel Configurations, Lower Latency, and Improved Control

Audinate announced a firmware update for OEMs building low-channel-count audio network products with dedicated four-channel input (4x0) or output (0x4) configurations at 96 kHz, while minimum device latency has been reduced from 2 ms to 1 ms for both 2x2 and 4x4 versions. The new firmware also delivers improvements to the Dante Device Protocol (DDP) that enable visual product identification on a network and greater control capabilities via GPIO. Read More

DirectOut and Merging Support Low-Latency Streaming of 256 Audio Channels via RAVENNA

DirectOut Technologies and Merging Technologies have announced high-performance interoperability of both their in-house developed audio network cores using RAVENNA technology. DirectOut's new MONTONE.42 audio-over-IP (AoIP) bridge supports low-latency streaming of 256 audio channels to and from Merging's Pyramix Virtual Studio DAW. Read More

Yamaha Announces New DXS18 Best-in-Class Powered Subwoofer

Yamaha announced the release of the DXS18, the newest addition to the DXS Series of powered subwoofers. Joining the DXS12 and the DXS15 models, the DXS18 delivers the highest output level of the series as well as the lowest frequency range capability, while offering improved cabinet construction, DSP processing, protection functions, and crossover control. Read More

AES Announces 140th International Convention to Take Place in Paris, France, June 2016

Treasure Trove

The Decibel

By Ed Simon

The decibel is one of those wonderful bits of jargon that we use to confuse the uninitiated. Please do not read further unless you already know the secret sign and password.

The base unit is the bel, which is the logarithm base 10 of the ratio of the sound being measured to the threshold of hearing. Thus, if the sound energy is 10 times louder than our threshold of hearing it is log(10/1)=1. If the sound is 100 times louder, it is 2 bels, 1000 times louder is 3 bels, and so on. Just count the number of zeroes after the 1.

You can hear over a range of greater than 12 bels (120 decibels), which, when written out, is 1,000,000,000,000 to 1. Writing 120 dB is much easier. The decibel becomes confusing when you have, for instance, only twice the energy. The math works out to 10 (to convert from bels to decibels) � logarithm (2/1). Use a calculator to do the logarithm, which works out to a two-fold increase, or 3.010299957... decibels, which you can round off to 3. With 10 times as much energy (1 bel), you get 10 decibels. If you double the sounds' energy again, it cannot be 20 decibels because that is 100 times as loud.

You now know the secret of logarithms: add the 3 from the doubling to the 10 from the 10-fold increase to determine that the energy increases by 13 dB. Thus, 40 times as much energy would be 3 + 3 + 10, or 16dB. Eighty times, of course, is 3 + 3 + 3 + 10, or 19 dB.

If you know that 20 dB is 100 times and 19 dB is 80 times, then what is 1 dB? Well, 100 divided by 80 is 1.25. The log of 1.25 is .0969100. Ten times that is close enough to 1 that you should see how this works. The precise answer is 10 to the exponent (1 dB/10 decibels to bel), which equals 1.258925412..., or 1.

Another consideration is the accuracy to which you can measure. It is fine measuring a voltage on a digital meter that is accurate to four digits. A change in barometric pressure of 1˝ will change some sound levels by about 0.2 dB. Wind and air movement also affects the readings. That is why sound pressure levels are rarely used with a resolution of greater than 1 dB.

This text was featured in audioXpress May 2007, as a side note to the author's "Speech Intelligibility" article series. We thought this would be a good time to share it again.

And check the great decibel meter apps. Click on the two pictures.

From the Vault

Audio-Optical Isolation Amp

By Jenoe Keceli

When we connect audio components, interference may occur from various power and signal grounds. This circuit enables the full galvanic isolation of sound frequency signals with optical transmission in excellent quality, eliminating interference. The author describes a project using the IL300 linear optocoupler and a photovoltaic receiver in a standalone configuration with its own AC power supply, as well as a second galvanic isolation amplifier, planned for installation in an amplifier or other equipment and powered from a single ended DC supply. This article was originally published in audioXpress October 2004. Read the article here

Voice Coil Spotlight

Listen Releases SoundCheck 14 - Now Also Available for Mac OS X

By Vance Dickason

Listen, Inc., has released SoundCheck 14. This new version of the company's audio measurement software includes many features to simplify user setup, such as a redesigned setup wizard that guides you through the process of copying your settings and sequences to the new version. SoundCheck 14 is also the first software version available as a native 64-bit application for use on Mac OS X. Read the Full Article

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