KRK Systems Launches New Rokit Generation 3 Monitors

KRK Systems, now part of the Gibson Pro Audio division, claims it is the leader in the worldwide home studio market when it comes to powered monitors. KRK Systems is certainly one of the world’s most respected studio reference monitor manufacturers. So, when the company decided to refresh its popular Rokits, now in its third generation, there must have been a good reason.

KRKg3-familyWithout dramatic changes, the new Rokit G3 family shows a cleaner more refined look and finishing, with “radiused” edges that help reduce distortion from diffraction. The monitors now offer a new 1” soft dome tweeter and new glass-Aramid composite woofers. The changes expand the Rokit’s frequency response up to 35 kHz, with better vocal clarity and extended bass response from 35 Hz. The proprietary bi-amped, Class-A/B amplifier provides SPL up to 109 dB and the waveguide design helps achieve the detailed imaging, while the front-firing bass port reduces boundary coupling to enable flexible room positioning. One of the key changes is in the back of the monitors, where high-frequency adjustments can be found to tailor the system to the user’s personal taste. The low-frequency adjustments compensate for room acoustics.

KRK Sytems, Inc.
www.krksys.com

Radial Engineering USB-Pro High-Resolution, 24-Bit, 96-kHz Stereo Direct Box

The USB-Pro ($220 retail) is a high-resolution stereo direct box designed to convert sound files from a laptop computer and transfer them to a pair of balanced audio outputs to feed a PA, recording, or broadcast mixing console.

According to Radial President Peter Janis, “For years, Radial customers have been asking us to get into the digital world. We have hesitated due to lack of clear standards and challenges with respect to interfacing with computers. But with the recent advent of self-configuring USB ports, we feel the time is right to finally get involved and the USB-Pro is the first Radial product to sport digital connectivity.”

The Radial USB-Pro, a high-performance stereo direct box, integrates a built-in headphone amplifier and balanced Lo-Z outputs with switchable isolation.

The Radial USB-Pro, a high-performance stereo direct box, integrates a built-in headphone amplifier and balanced Lo-Z outputs with switchable isolation.

Made to be Plug & Play, easy to use, the USB-Pro automatically configures itself for use with all popular operating systems including Mac OSX, Windows XP, Vista, and Windows 7, eliminating the need to load special drivers. And unlike devices that are limited with 16-bit, 44.1-kHz conversion rates, the USB-Pro elevates the performance with 24-bit, 96-kHz stereo converters to deliver more headroom and greater detail. This eliminates the need for additional sound cards or separate converters when transferring files, further streamlining production in busy work environments.

Connection from the laptop is done via the pro-audio standard USB type-B port. D/A conversion is monitored with the built-in headphone amplifier to ensure the signal is properly downloaded and converted. A monosum switch may be engaged to check for phasing or facilitate signal distribution to two outputs should this be preferred. Just set the output volume control.

Should hum or buzz caused by ground loops be encountered, two set-and-forget side-access switches enable you to insert isolation transformers into the signal path to block stray DC voltage offsets. To further reduce susceptibility to noise, this is augmented with a ground lift switch that lifts pin 1 on the two XLRs.

The Radial USB-Pro is designed to handle the rigors of professional touring with protective zones around the switches, connectors, and controls to keep them out of harm’s way. Inside construction ensures the internal PC board will not torque, which could cause premature part failure. Finally, a full-bottom no-slip pad provides mechanical isolation and electrical insulation.

Radial Engineering, Ltd.
www.radialeng.com

Tascam’s High-End Master Recorder and ADDA Converter

Tascamda-3000_p_frIt is good to see new product launches from the TEAC group’s pro audio brand after its recent acquisition by Gibson, especially this upgrade to the legendary DV-RA1000HD recorder. The new Tascam DA-3000 offers the same famous Burr-Brown (now Texas Instruments) ADCs but it comes with a high-quality op-amp (NE5532), optimum condensers, and high-specification resistors for low-noise, high-accuracy, and high-heat capacity in a sleeker, more modern design. This new high-definition master recorder/ADDA converter is designed to fit in any professional or home recording studio, for recording, mastering, broadcasting, replacing a DAT machine, or for audiophiles who want to upgrade their files. This recorder supports high sampling rates up to 192 kHz pulse code modulation (PCM) and 5.6 MHz direct-stream digital (DSD), with the option of recording to SDHC and compact flash with support for USB memory playback.

Tascamda-3000_w_boThe high-precision TCXO fan-less design ensures pristine audio quality. The dual-monaural DACs help eliminate any interference. A balanced XLR I/O, unbalanced RCA I/O along with digital audio I/F AES-EBU, S/PDIF for PCM, and SDIF-3/DSD-raw for DSD is located in the rear of the unit. The DA-3000 warrants a clock frequency accuracy of 1 ppm by TCXO and uses a crystal direct system for low jitter.

The dual-monaural DAC is configured with Texas Instruments (TI) ICs (PCM1795) for each channel and uses TI’s PCM4202 on the A/D conversion, adding an E-I core power transformer with separated coils for digital and analog circuits.

TEAC Corp.
www.tascam.com

Avid S3L: A New AVB-Based Live Sound Mixing System

A networked, modular digital mixing system for professional live sound and studio applications is realized through the tight integration of technologies, including EUCON for networked control, AVB for networked audio, HDX floating-point processing, AAX plug-ins, and VENUE and Pro Tools software applications.

A networked, modular digital mixing system for professional live sound and studio applications is realized through the tight integration of technologies, including EUCON for networked control, AVB for networked audio, HDX floating-point processing, AAX plug-ins, and VENUE and Pro Tools software applications.

Following the Venue systems, which enabled Avid to get a strong foothold on the live sound market, the company has introduced a new compact modular system for that market built on audio video bridging (AVB) standards. Avid has always been part of the AVB efforts from its early beginnings and it is currently a promoter in the AVnu Alliance, an industry forum dedicated to the advancement of professional-quality audio/video by promoting the adoption of the Institute of Electrical and Electronics Engineers (IEEE) 802.1 Audio Video Bridging (AVB) and the related IEEE 1722 and IEEE 1733 standards over various networking link layers.

The new modular Avid S3L System leverages the best technology from Avid’s successful recording technologies (Pro Tools) and combines it with the expertise gained in the industry with its Live solutions (e.g., the VENUE software that drives the system). The S3L System implements a modular system architecture comprising a high-performance HDX-powered processing engine running AAX plug-ins from its studio technology with the scalable remote I/O (up to 64 microphone inputs) that can work on stage or in a rack, and a clever compact control surface built for the road, which could be equally at home in the studio.
The system uses Dual Gigabit Ethernet ports with latching etherCON connectors, supporting both the Ethernet AVB and EUCON standards. Due to the accessible entry-level price (starting at $17,995), this is an interesting solution that helps bring more awareness to the full potential of networked audio solutions based on recent standards.

The S3L can be configured with up to four Stage 16 remote boxes, while the S3 compact 16-fader control surface can be easily transported as carry-on luggage. Direct recording/playback to Pro Tools (or other DAW) is possible through a laptop Ethernet port while direct stereo recording/playback can be achieved with any standard USB flash drive. Show files are compatible with all Avid Venue live systems.

Avid S3L is now shipping.

Avid Technology, Inc.
www.avid.com

LSR 3 Series: Affordable Studio Monitors From Jbl Professional

The 3 Series studio monitors leverage the new technology developed for JBL’s flagship M2 Master Reference Monitor.

The 3 Series studio monitors leverage the new technology developed for JBL’s flagship M2 Master Reference Monitor.

JBL Professional introduced a new professional studio monitoring range at an affordable price. The 3 Series studio monitors leverage the new technology developed for JBL’s flagship M2 Master Reference Monitor, which was launched earlier this year. This is also the first studio monitor line to incorporate JBL’s patent-pending Image Control Waveguide, with a distinctive appearance and rugged build.

The JBL 3 Series features two models: the LSR305, 5” powered studio monitor and the LSR308, 8” powered studio monitor. The LSR305 responds from 43 Hz to 24 kHz and a 108-dB peak sound pressure level (SPL). The LSR308 features a 37-Hz-to-24-kHz response and a 112-dB peak SPL.

Surrounding the high-frequency tweeter and located directly above the woofer, the new Image Control Waveguide precisely controls the sound emanating from the monitor in the vertical and horizontal planes. With a complex contour employing tiny, meticulously engineered ridges, the waveguide optimizes the loudspeakers’ phase relationship, and the blend of directed and reflecting sound arriving at the listening position. In addition, the waveguide enables 3 Series models to deliver neutral sound across a large working space.

The 3 Series’s long-throw woofer and damped woven composite tweeter are designed to reproduce the powerful transients and microdynamics of any mix. JBL’s patented Slip Stream low-frequency port design works with the woofer to produce deep bass response at all playback levels. The port’s double-flared shape is precisely engineered for greater low-frequency extension and reduced turbulence. Efficient Class D amplifiers provide enough power to the drivers to deliver the output and dynamic headroom needed for the most demanding production styles.

Each 3 Series model incorporates a range of features to integrate the loudspeakers into a variety of environments including multiple inputs, a detented volume control, and an input sensitivity switch for compatibility with professional and consumer equipment.

The loudspeakers cost $199.99 and $325 for the LSR305 and LSR308, respectively.

JBL Professional
www.jblpro.com/3series

Industry Watch: October

CEDIA 2013 Manufacturers’ Excellence Awards

The Custom Electronic Design & Installation Association (CEDIA) has announced the 2013 Manufacturers’ Excellence Awards finalists. Thirty-one product finalists were named in the Best New Product category and two product finalists were named in the Sustainable Lifestyle Product Innovation category. The award winners were announced at a press conference on Friday, September 27, at the 2013 CEDIA EXPO.

In addition, winners were also recognized at the annual Electronic Lifestyles Awards Celebration on Saturday, September 28. Both events occurred after this issue was printed. Winners will be announced in Voice Coil’s November issue. The loudspeaker-related finalists included:

  • Core Brands (CEDIA founding member)—Niles Cynema Soundfield In-Wall Soundbar (see Photo 1)

    Photo 1: Niles Cynema’s Soundfield in-wall soundbar received the CEDIA Manufacturers’ Excellence Award

    Photo 1: Niles Cynema’s Soundfield in-wall soundbar received the CEDIA Manufacturers’ Excellence Award

  • Sonance (CEDIA founding member)—Sonarray SR1 System outdoor speaker system (see Photo 2)

    Photo 2: Sonance’s Sonarray outdoor system also received the CEDIA Manufacturers’ Excellence Award.

    Photo 2: Sonance’s Sonarray outdoor system also received the CEDIA Manufacturers’ Excellence Award.

  • Sonance—SLS High Output outdoor speaker system
  • Sonance—Visual Performance VP66 In-Wall Speaker

 


CEDIA Benchmarking Surveys

If you manufacture loudspeaker products for the custom install market, it is important to stay informed with the installer network. CEDIA has released key findings from its 2013 Benchmarking Surveys, which evaluate the performance and the state of home technology professional companies for 2012 and reports on 2013 expectations.

The results conclude that home technology professional companies continue to experience moderate growth, focusing on operational efficiencies (historically, one of the largest prohibitors of profitability) and are ready to bring in additional staff to accommodate a growing workload.

The 2012 survey participants expected a revenue increase of 12% from 2011. The 2013 participants reported a 10% actual increase and an 18% expected increase in 2013.

The median number of employees stayed flat from 2010, 2011, and 2012 with six employees per company (full- and part-time), while revenue per employee rose from $135,000 in 2011 to $145,950 in 2012. However, participants indicated they will increase their staff by 14% in 2013.

In 2012, there was a stronger commitment to operational efficiencies with 80% of the participants reporting that they focused on standardizing operational practices in 2012 for increased profitability. This was the most applied tactic out of the 10 presented.

Of the participants offering recurring monthly revenue services, the percentage of companies offering remote network monitoring and diagnostic services continues on a strong positive trend (e.g., 16% in 2011, 32% in 2012, and 41% in 2013).

The survey report, compiled by Profit Planning Group, provides detailed benchmarks, best practices, and trend analysis based on data collected from home technology professional companies. All the survey participants received a customized report comparing their companies to similar-size companies, the industry median, and the most profitable industry companies. This custom report also included a suggested action plan for increasing profitability and trend analysis for participants of more than one year. The estimated value of this custom analysis is $2,500.

For the first time, CEDIA is also offering free condensed versions of the reports to all CEDIA members as a membership benefit. The full survey reports are available for purchase through the CEDIA Marketplace at the following rates:

  • 2013 CEDIA Benchmarking Survey—Finance, Project Management, & Marketing: $700 for members/$1,200 for non-members
  • 2013 CEDIA Benchmarking Survey—Staffing, Benefits, & Compensation: $300 for members/$800 for non-members

For more information about the CEDIA Benchmarking Surveys and member report access, visit www.cedia.net/benchmarking or e-mail research@cedia.org.

 


First Annual TWICE VIP Awards

The nominations were submitted, the voting took place, and the selections were made for TWICE magazine’s first-ever products awards—the TWICE VIP (Very Important Product) Awards.

Retailers and distributors voted online for the TWICE VIPs, honoring the products that have made the biggest differences in their businesses.

Retailers and distributors voted on products in specific categories based on product features, product design, and consumer value. The eligible products retailed in the US, or were scheduled to be sold at retail, from fall 2012 to spring 2013.

The categories included:

  • Accessories: gaming peripherals, HDMI cables, headphones less than $300, headphones more than $300, health and fitness technology products, mounting accessories, power and charging devices, projector screens, smartphone accessories, and tablet accessories
  • Camcorders: action video camcorders
  • Cameras: DSLRs (interchangeable lens) and point-and-shoot cameras
  • Car: connectivity to mobile device for in-dash head units, remote security/convenience system controlled from a smartphone, and car speakers
  • Computers and Tablets: tablets and laptops
  • Home Audio: A/V receivers $699 or less, A/V receivers more than $699, iPod/iPhone docking speakers, portable wireless speakers, soundbars at $499 or less, and soundbars more than $499
  • Major Appliances: bottom-mount refrigerators and high-efficiency (HE) washers
  • Video and TVs: big-screen flat-panel TVs (42” to 55”), big-screen flat-panel TVs (58” and larger), streaming IPTV set-top devices, and home-theater projectors

Loudspeaker-related winners were:

  • Headphones More Than $300: Polk UltraFocus 8000
  • Headphones Less Than $300: Skullcandy Crusher
  • Soundbars $499 or Less: Harman International JBL Cinema SB200
  • Car Speakers: Pioneer Electronics TS-A1605C 6.5” Component Speaker
  • Soundbars at More Than $499: Samsung Electronics HW-F750 2.1-Channel (see Photo 3)

    Photo 3: Samsung’s  HW-F870 soundbar received a Twice VIP award.

    Photo 3: Samsung’s HW-F870 soundbar received a Twice VIP award.

 


Klipsch History

Loudspeaker engineer Jim Hunter wears many “hats” at Klipsch, among them is company historian. Keeping the historical records of Paul Klipsch is important for Klipsch, and to the rest of us. Paul Klipsch was an important pioneer in the loudspeaker industry and knowing the “rest of the story” is fascinating. To that end, Hunter (who gave a great presentation on Klipsch history at the 2013 ALMA Symposium) has recently updated Paul Klipsch’s historical information on the Klipsch website (www.klipsch.com/founder).

 


Advanced Audio Systems Engineer Joins MISCO

Photo 4: Engineer Richard Field joins MISCO.

Photo 4: Engineer Richard Field joins MISCO.

Richard Field has joined MISCO, a US-based global manufacturer of speakers and audio systems, as a design engineer (see Photo 4). Field has a BS from Southern Illinois University in audio electronics. His loudspeaker engineering career spans more than 25 years. He was an automotive transducer specialist for Harman. He also designed transducers, loudspeakers, and active systems for Klipsch. One of Field’s noteworthy designs was the award-winning Klipsch ProMedia series of personal audio systems. Field also spent three years at Loudspeaker Component designing cones, tools, and processes.

“Richard’s love of loudspeakers shows in his long list of successful and profitable designs,” said Dan Digre, MISCO’s general manager. “[This] makes him a perfect fit for our seasoned engineering team. Richard had the good fortune to work directly with audio engineering luminaries such as John Eargle and Richard Small. And he has vast experience interacting with manufacturing facilities around the world. We’re really looking forward to working with Richard and everything he brings to the MISCO engineering team.”

 


Onkyo’s Active Soundbar

Onkyo has launched its first active soundbar and TV-speaker base. The new products join a 2.1-speaker home theater system in the Envision Cinema product series, which are designed to deliver home-theater audio with simple setup (see Photo 5).

Photo 5: Onkyo received the TWICE VIP award for its LS-B50 soundbar.

Photo 5: Onkyo received the TWICE VIP award for its LS-B50 soundbar.

The LS-B50 soundbar and wireless subwoofer has a $699 suggested retail price. The LS-B50 also doubles as a music system and will “talk” to Bluetooth and USB ports, which play audio from smartphones, tablets, and mass-storage devices. This soundbar features Dolby Digital 5.1 decoding, one optical input, one coaxial input, and one analog input.

As with the Onkyo Envision series’ $499 LS3100 2.1-speaker system, the LS-B50 is preprogrammed with the IR codes of nine major TV brands so it can be controlled from a TV remote. However, it is also equipped with its own remote. The LS-B50 also features a six-channel amplifier and proprietary AuraSphere DSP, which according to Onkyo, expands the traditional audio sweet spot from directly in front of the TV to the entire room. The technology manages equalization and sound pressure levels (SPL) in real time to create a “realistic 3-D immersion field” from PCM stereo and Dolby Digital audio sources, the company added.

The LS-B50 soundbar features six 2.75” diameter full-range drivers, two 1.19” diameter ring-radiator tweeters, and wireless 6.5” subwoofer. Three sound modes optimize playback of different audio content. The News mode cleans up and projects dialog more intelligibly. The Movie mode enhances the movie soundtracks’ impact. The Music mode delivers more balanced sound across the frequency range. The output is 40 W into 4 Ω. It comes with a wall-mounting kit and IR flashers for flexible placement options.

 


Sony’s 7.1-Channel Soundbar

Sony has launched the HT-ST7, a new “high-end” $1,299 soundbar (see Photo 6). The 7.1-channel HT-ST7 soundbar, which does not carry the Sony ES high-performance series designation, is now sold at Sony Stores and electronics retailers nationwide (e.g., Best Buy).

The product, engineered in collaboration with sound engineers at Sony Pictures Studios, features an aluminum chassis that incorporates Dolby TrueHD and DTS-HD Master Audio decoders, nine independent speaker drivers, seven amplifier channels, three HDMI inputs, an HDMI output with audio return channel, three S/PDIF digital audio inputs, one analog-audio input, magnetic-fluid speakers, S-Master digital amplifiers, and S-Force Pro Front-Surround technology. The HT-ST7 also features built-in wireless Bluetooth and supports AAC and aptX streaming over Bluetooth. The soundbar’s nearfield communication (NFC) technology enables users to tap their mobile Bluetooth devices to establish Bluetooth connections and stream music.

 


Vizio Launches Three New Soundbars

Vizio has added three more soundbars, the S2929w, the S3820w, and the S3821w, with built-in Bluetooth to its 2013 lineup. The three new soundbars are in addition to the two models shipped earlier this year at suggested prices of $249 and $329. All the soundbars are wall mountable.

The $79 S2920w shipped in September and the $119 S3820w and the $179 S3821w were available in August. The $79 model is sized for 32” TVs. the other two soundbars are sized for 42” TVs. The two step-up models currently shipping are designed for 47” TVs.

Among the three new models, all but the S2920w feature Dolby Digital decoding. All three soundbars feature DTS TruVolume, DTS TruSurround technology, optical and coaxial digital inputs, and an analog RCA input. The S3821w model includes a wireless outboard 6” subwoofer. The S2920w delivers 95-dB SPL and 90-Hz bass response. The S3820w raises the output to 98 dB and deepens bass response to 65 Hz. The S3821w model delivers 100-dB SPL and 50-Hz bass response. All the soundbars share a design inspired by Vizio’s near-borderless M-Series Razor LED smart TVs.

Vizio’s top-end $329 S4251w is a 5.1 system that includes wireless surround speakers and a wireless subwoofer. Vizio uses its online social community, Vizio Fandemonium, to promote the products and give its fans exclusive access to a custom Pandora station and a chance to win a DTS-equipped soundbar.

 


CEA Consumer Confidence Study

Consumer confidence in the overall economy improved slightly, while sentiment toward technology spending remained flat in July, according to the latest figures from the Consumer Electronics Association (CEA). The CEA’s Index of Consumer Expectations (ICE), which measures consumer expectations about the broader economy, increased 2.3 points in July to reach 167.8. The ICE remains 5.1 points lower than in July of 2012. The CEA Index of Consumer Technology Expectations (ICTE), which measures consumer expectations about technology spending, decreased 0.3 points in July to 86.2. However, the ICTE is 2.9 points higher than the July average over the last three years.

The CEA Indexes comprise the ICE and ICTE and are updated on a monthly basis through consumer surveys. New data is released on the fourth Tuesday of each month. CEA has been tracking index data since January 2007. To find current and past indexes, charts, methodology, and future release dates, visit CEAindexes.org.

Steinberg, MXL, Mogami, and Yamaha Offer High-Value Recording Packs

Cubase7-UR22RecordingPacksMontageWebFour of the top names in recording, Steinberg, MXL, Mogami, and Yamaha announce the Cubase Recording Pack and the UR22 Recording Pack, two new recording packs that offer musicians, engineers, and producers the best brands in the box.

The Cubase Recording Pack comes with Cubase 7 and the UR22 audio interface from Steinberg, along with an MXL1022 condenser microphone, a MXL-57 shock mount, and a Mogami 10’ XLR-XLR cable. The Cubase Recording Pack also includes a pair of Yamaha RH5MA headphones, which is the final component in this instant recording studio solution.

The second bundle, the hardware-oriented UR22 Recording Pack, features the UR22, an MXL1022 condenser microphone, an MXL-57 shock mount, and a Mogami 10’ XLR-XLR cable. The UR22 Recording Pack is designed for first-time audio interface users who seek a high-quality solution featuring trustworthy brands.

One of the world’s most popular digital audio workstations, the Cubase 7 features the new MixConsole, enhanced workflow options, and a new channel strip that offers epic pro-console sound. The rock-solid UR22 USB 2.0 audio interface includes two D-PRE preamps and 192-kHz support, providing professional-grade sound in a portable package.

The MXL1022 large-diaphragm condenser microphone captures vocals and instruments in crisp detail. It features an FET preamp with balanced output and wide frequency response to pick up a broad range of sound, from vocals to a variety of instruments. The microphone is internally wired with world-class Mogami cable for precise recordings and, when placed into the MXL-57 shock mount, ensures professional performance.

The 10’ XLR-XLR Cable from Mogami, the largest-selling cable brand for major recording facilities, delivers the purest recordings. Each cable is made from Mogami’s 2552 microphone cable with signature Mogami 100% spiral coverage for extremely low noise. The cable is finished with high quality gold-contact XLR connectors.
Yamaha RH5MA headphones, which provide accurate sound reproduction, represent an excellent choice for pro studio monitoring. Featuring a semi-closed design, they come with 0.25” and 0.125” inch jacks along with an 8’ long cable. The frequency response is 20 Hz to 20 kHz and the impedance is 32 Ω.

The Cubase Recording Pack costs $1,119.99. The UR22 Recording Pack costs $439.99.

The Cubase Recording Pack includes Cubase 7 Upgrade 4 to “upgrade” the existing license, pre-loaded onto the included eLicenser USB key. The UR22 Recording Pack includes a Full Version of Cubase AI 7.

Expanding horizons. Expanding a common passion.

AXCover_112013Nov_120xWelcome to a new audioXpress.

Having followed the audio market and visited the world’s major trade shows for the last 20 years or more, I gained a broad perspective about how exciting and innovative the audio industry is. In particular, I recall the enlightening perspective you can receive from any Audio Engineering Society (AES) convention. The convention provides a place where industry veterans can share their experiences in engineering and communications. We chose to unveil the redesign of audioXpress at the 135th AES Convention.

In the early 1990s, I was fortunate enough to be responsible for a licensed electronics magazine. I quickly learned that the audience of such practical and project-oriented publications was a combination of students, enthusiasts, and industry professionals. They all share a passion for that field, are involved in many different areas, and use their spare time to pursue electronics-related hobbies—the most popular of which is audio electronics.

Since then, I have started several publications addressing the informational needs of professionals in the broadcasting, professional audio, and installation/systems integration markets. I also learned how the evolution of technology from analog to digital and the convergence with IT platforms and IP infrastructure was changing the market landscape at an exponential pace.

During this time, Edward T. Dell, Jr. (1923–2013) was devoting his life to people with a passion for audio electronics and creating magazines including Audio Amateur (rebranded as Audio Electronics in 1996), Glass Audio, Speaker Builder, and later, in 2000, audioXpress. In 2011, Ed Dell sold his company to Elektor International Media (EIM) and retired.

Much in the same spirit of the original Audio Amateur—and with the support of a worldwide organization deeply involved in the electronics industry—we believe that audioXpress will blossom into a fascinating publication that follows the latest audio innovation trends, independent of the application field, and shares a common audience of engineers, consultants, and enthusiasts in the electronics and audio fields, most of whom are involved in R&D.

Although it was deeply rooted in the US, audioXpress—together with its sister publications Voice Coil and the Loudspeaker Industry Sourcebook—reached professionals around the world (e.g., Europe, China, India, and Brazil). It has gained more of a global presence since its acquisition by EIM, which also publishes some of the best technical books in the electronics industry.

I am really excited to bring the “new” audioXpress to a wider global audience, knowing that we can build on the tradition of the original publication and its diversified audience. We are working to create a magazine you will enjoy and anticipate reading every month.

João Martins
Editor-in-Chief

Member Profile: Dennis Green

Member Name: Dennis L. Green

Location: Farmington Hills, MI

Education: BSEE

Occupation: Retired

Member Status: Dennis has been a subscriber since the first issues of Audio Amateur and Speaker Builder. He switched to audioXpress after their demise, mostly for the component ads and the solid-state and speaker projects.

Affiliations: Dennis is a member of the Institute of Electrical and Electronics Engineers (IEEE), the Audio Engineering Society (AES), and Southeastern Michigan Woofer and Tweeter Marching Society (SMWTMS).

Audio Interests: His primary audio interests focus on homebrew audio and field recording.

Most Recent Purchase: Dennis recently added an Apex Jr. subwoofer amp to his audio lineup.

Current Audio Projects: He is currently working on an optical sensor-based servo control upgrade for the Kilmanas Rabco tonearm featured in an Audio Amateur article in March 1976.

Dennis recently moved and has a temporary setup for his vast sound system.

Dennis recently moved and has a temporary setup for his vast sound system.

Dream System: Dennis said his dream system includes a home theater using Quad ESLs in a custom room. However, Dennis said he is “not at all unhappy” with his present system.” His current system includes: Swan IV satellites built from an April 1988 Speaker Builder article, four Peerless 8” midrange woofers (each side in concentric Sonotubes with sand damping in the space), and a Cerwin-Vega 189E  driver (salvaged from the movie Earthquake Sensurround system) in an enclosure that formerly contained a Jolly Giant system. The Jolly Giant system used a Hartly 24-inch “tweeter” and was also built using a Speaker Builder article. (Dennis intended some sarcasm here since that speaker radiated more energy at 20 kHz than at 20 Hz.) His present system measures ±1 dB from 60 to 16 Hz and –10 dB at 12 Hz.

Dennis also has a Swan crossover modified with Linkwitz-Riley stage for a subwoofer (his design) and a Lampton preamp built from an Audio Amateur schematic. However, his design added switching and a rack-mount enclosure. He restored Quad 303 and Dyna Stereo 120 power amps and a Leach Low TIM amp (built from plans in Audio magazine) that are temporarily driving the subwoofer (a new amp will be installed soon). He said his system is not very presentable since he has moved to a new home and remodeling projects have taken priority.

Gel-Based Speaker Demonstrates Ionic Conductor Capabilities

Jeong-Yun Sun (left) and Christoph Keplinger (right) demonstrate their transparent ionic speaker, which uses a signal conducted by ions rather than electrons to vibrate a rubber membrane. (Photo courtesy of Eliza Grinnell, SEAS Communications)

Jeong-Yun Sun (left) and Christoph Keplinger (right) demonstrate their transparent ionic speaker, which uses a signal conducted by ions rather than electrons to vibrate a rubber membrane. (Photo courtesy of Eliza Grinnell, SEAS Communications)

Researchers Jeong-Yun Sun and Christoph Keplinger at the Harvard School of Engineering and Applied Sciences (SEAS) have demonstrated a new type of loudspeaker transducer, which works on a different principle than the conventional moving coil design.

It is made of a thin sheet of transparent rubber sandwiched between two layers of salt-water gel. A modulated high-voltage signal passed across the two outer gel layers exerts pressure on the rubber membrane, causing it to vibrate and produce sound, much like a planar (or flat) speaker. According to the Harvard SEAS report, the prototype speaker has a 20-Hz-to-20-kHz frequency response.

The important thing is that the vibration effect is produced by the electrical charges carried by ions and not the movement of electrons. So strictly speaking, this is not an electronic device. And the speaker is clear as a window.

The high-voltage signal that runs across the surfaces and through the layers forces the transparent rubber to rapidly contract and vibrate, producing sound.

Published in Science’s August 30, 2013, issue, this new speaker represents the first demonstration that electrical charges carried by ions, rather than electrons, can be put to meaningful use in fast-moving, high-voltage devices.

“Ionic conductors could replace certain electronic systems; they even offer several advantages,” says co-lead author Sun, a postdoctoral fellow at Harvard SEAS.

For example, ionic conductors can be stretched to many times their normal area without an increase in resistivity—a problem common in stretchable electronic devices. Second, they can be transparent, making them well suited for optical applications. Third, the gels used as electrolytes are biocompatible, so it would be relatively easy to incorporate ionic devices (e.g., artificial muscles or skin) into biological systems or wearable devices.

According to Keplinger, who worked on the project as a postdoctoral fellow at Harvard SEAS and in the Department of Chemistry and Chemical Biology, such systems have great potential as sensors and for actuating automatically on movement, which opens a range of application possibilities.

The audio speaker represents a robust proof of concept for ionic conductors because producing sounds across the entire audible spectrum requires both high voltage (to squeeze hard on the rubber layer) and high-speed actuation (to vibrate quickly)—two criteria that are important for applications but would have ruled out the use of ionic conductors in the past.

The electrical connection to the power source is established outside the device’s active region where it does not need to be transparent. The traditional constraints are well known. High voltages can set off electrochemical reactions in ionic materials, producing gases and burning the materials. Ions are also much larger and heavier than electrons, so physically moving them through a circuit is typically slow.

The system invented at Harvard overcomes these problems. “It must seem counterintuitive to many people that ionic conductors could be used in a system that requires very fast actuation, like our speaker,” says Sun. “Yet by exploiting the rubber layer as an insulator, we’re able to control the voltage at the interfaces where the gel connects to the electrodes, so we don’t have to worry about unwanted chemical reactions. The input signal is an alternating current (AC), and we use the rubber sheet as a capacitor, which blocks the flow of charge carriers through the circuit. As a result, we don’t have to continuously move the ions in one direction, which would be slow. We simply redistribute them, which we can do thousands of times per second.”

According to Keplinger, “Our system doesn’t need a lot of power and you can integrate it anywhere you would need a soft, transparent layer that deforms in response to electrical stimuli (e.g., on the screen of a TV, laptop, or smartphone to generate sound or provide localized haptic feedback). People are even thinking about smart windows. You could potentially place this speaker on a window and achieve active noise cancellation with complete silence inside.”

The Harvard team chose to make its audio speaker out of simple materials. The electrolyte is a polyacrylamide gel swollen with salt water, but the team emphasized that an entire class of ionically conductive materials is available for experimentation. Future work will focus on identifying the best combinations of materials for compatibility, long life, and adhesion between the layers.

Harvard School of Engineering and Applied Sciences
www.seas.harvard.edu