Radio World

What are the primary benefits of virtualization to radio broadcasters? Are we farther along now than a year ago in seeing virtualization come to PPM, to EAS? What are common misconceptions or unfamiliar terms in virtualization that readers should be aware of?

Those are some of the questions explored in our new ebook “What’s Next for Virtualization?”

Editor in Chief Paul McLane talked with six manufacturers and software sponsors about their applications of the concept of virtualization, and he checked in with prominent industry engineering executives for an assessment of the relevance and impact of virtualization.

How close are we to a fully virtualized air chain? What else should we know on this topic? Find out in the latest free ebook.

Read it here.

The post What’s Next for Virtualization? appeared first on Radio World.

At Thursday’s FCC meeting, Acting Chairwoman Jessica Rosenworcel used the occasion of her trip to Louisiana to explain several commission initiatives.

 In a written statement, she described the damage done by Hurricane Ida and summarized steps the FCC had taken before and after that storm.

 “But we have to understand where communications fell short, where recovery took too long, and what changes can be made to make our networks more resilient before the next unthinkable event occurs,” she wrote in comments released by her office.

 She talked about the NPRM that the FCC has adopted to strengthen its DIRS system and possibly to require backup power at communications facilities including broadcast stations.

The text of her statement is below:

This week I had the opportunity to see firsthand the devastation wrought by Hurricane Ida. Commissioner Carr joined me to crisscross a long, flat stretch of Louisiana — from Baton Rouge to New Orleans. The drive itself was telling. Along the way we saw cruel reminders of the storm and the great damage wind and water can do — mangled store signs and piles of refuse still being cleared away. Still, what struck me most was all the blue. Not the grey-blue of Lake Pontchartrain. Instead, it was the bright blue of heavy plastic tarps. They were everywhere. On the pitched rooves of homes. On the flat tops of commercial buildings. They were part of fixing what had blown away.

That image stays with me. But so does the strength and resilience of everyone we met. They love where they live and are deeply committed to restoration in their communities. They are also deeply invested in making sure that when the next storm comes — and it will — they are better prepared. Being better prepared means having more resilient communications. It means making sure our networks work when we need them most. I spoke with Governor John Bel Edwards about this before our trip and I heard it from everyone we met — state public safety leaders in Baton Rouge, 911 call center operators in Livingston, broadband companies in LaPlace, and FirstNet officials in Raceland.

Everyone we spoke with wanted to tell us their stories and give us their ideas. They wanted us to know what worked and what didn’t and how stronger and more resilient communications can save lives. I’m grateful Commissioner Carr was able to join me and thank all my colleagues for supporting the swift actions the agency took to assist before and after the storm.

In anticipation of landfall, the Federal Communications Commission set up an information hub for Hurricane Ida, with emergency communications tips in nine languages, tailored media advisories for broadcasters, downloadable Public Service Announcements, communications status reports, and other content.

We deployed FCC staff to Louisiana and the Federal Emergency Management Agency Regional Response Coordination Center in Dallas, Texas, to support spectrum management, perform damage assessments, and prioritize recovery efforts.

In coordination with FEMA and other federal partners, we activated our Disaster Information Reporting System. As a result, we published the first comprehensive assessment of Hurricane Ida’s impact on communications networks followed by daily updates.

We provided technical assistance to 911 coordinators, State Emergency Operations Centers, 911 call centers, carriers implementing the Wireless Resiliency Cooperative Framework and other communications providers, and the Louisiana Association of Broadcasters.

We engaged in daily coordination with Federal, state, and local partners, as well as with industry, to help coordinate the transport of necessary communications equipment, fuel, and other resources to help fill communications gaps. We also set up a first-of-its kind team to address coordination with utilities to prevent accidental fiber cuts during debris removal and restoration.

Of course, we had help.  Communications companies worked long and hard to restore critical services. All of this made a difference. More than 98 percent of the cell sites in the affected counties have been restored. Other outages trended downward as fast as power was restored.

This is progress. But we have to understand where communications fell short, where recovery took too long, and what changes can be made to make our networks more resilient before the next unthinkable event occurs.

Today’s rulemaking gets that effort going. We start by taking a second look at the voluntary Wireless Resiliency Cooperative Framework and its disaster roaming and asking where can it be strengthened. Are best practices enough? Should coordination happen earlier? Be more automatic? This was something that came up repeatedly in our discussions in Louisiana — a desire for this cooperative roaming to work faster, work better, and help keep more people connected in disaster.

We also revisit our Disaster Information Reporting System and seek targeted comment on where there are gaps that need to be filled. 911 call centers should not be the last ones to find out where there are critical network failures. But we learned that during Hurricane Ida, that is exactly what happened. So we ask about how we can improve data collection and timely notification during disasters.

Finally, we renew our inquiry into backup power for communications facilities. Our review of the data collected in the aftermath of Hurricane Ida reveals that the lack of commercial power at key equipment and facilities is the single biggest reason why communications networks failed. Left unaddressed, this problem will only get worse in coming years as we experience disasters with increasing severity, duration, and impact. So our rulemaking explores resilience strategies for power outages — including better coordination between communications providers and power companies and backup power or other measures that could help keep service running after a disaster.

I am hopeful that this rulemaking is the beginning of a broader discussion of our need for resilient networks. Look around. We have hurricanes in Louisiana, a snowstorm in Texas, and wildfires out West. These issues are not going away. We need to think deeply about what network resiliency means and how our policies can support it. So in addition to this rulemaking, next month the FCC will hold a virtual field hearing on Hurricane Ida and the resilient networks now needed in disaster more generally. To make it simple, we’ll have it as part of our monthly open meeting in October. Stay tuned for details.

 

The post Rosenworcel Highlights Network Resilience appeared first on Radio World.

David H. Layer is vice president, advanced engineering at the National Association of Broadcasters. Radio World spoke with him recently ahead of the anticipated Broadcast Engineering & IT Conference at the NAB Show. The convention has since been cancelled but the activities discussed here continue. Here are relevant portions of our conversation.

Radio World: David, there is a Radio Committee of the North American Broadcasters Association, in which NAB is involved. What role is NABA playing right now in regards to the auto infotainment landscape?
David Layer: NABA serves as a bridge between Canada, the U.S. and Mexico regarding radio and TV broadcasting technical and regulatory issues. NABA’s Radio Committee has two active projects, one involving development of a NABA In-Car User Experience (ICUE) guideline that is based upon — and complements — an ICUE document developed by WorldDAB, the other on hybrid radio and metadata.

This second project involves developing resources and guidance for North American broadcasters on how to effectively support hybrid radio platforms and regarding the importance of having good textual and visual metadata which will make radio look as good as it sounds.

RW: Hybrid radio has occupied a lot of your attention recently, and we’ve written a good deal about the topic in Radio World. What’s your key message for broadcasters regarding hybrid radio?
Layer: It’s a straightforward message: for each station to provide good metadata support for their over-the-air and streaming audio products.

At NAB, we’ve been reaching out to broadcasters with this message and backing it up with information on specific metadata suggestions that are relevant to different types of stations.

For example, all analog FM stations and AM and FM HD Radio stations should be registered with RadioDNS, a nonprofit organization that develops and supports open technical standards for hybrid radio — unfortunately, analog AM stations are not at present supported since they have no data-carrying capability.

NAB recently updated and reissued the NAB Digital Dashboard Best Practices Report, which provides lots of detail and recommendations for broadcasters on how to implement and improve their metadata operations. I would encourage your readers to download and read this report.

RW: U.S. broadcasters seem to be cautious about building out the infrastructure to support hybrid radio. Why do you think that is?
Layer: I believe there are many broadcasters who have actually been bullish on hybrid radio and eager to provide top-notch support, encompassing both medium and large radio groups. I do not sense a lack of interest among broadcasters but I definitely think that there are resource issues contributing to a slower-than-desired rollout of support. And not surprisingly, these resource issues have been exacerbated by the pandemic.

RW: What specific make and models of cars now have hybrid radio available in North America, and when should we expect more?
Layer: I know that Audi, using their MultiMedia Interface or MMI, and Mercedes, using DTS AutoStage, are shipping cars with hybrid radio receivers to North America, but I do not know the model breakdown. Also, there are BMW cars in North America that use RadioDNS for station information and logos but do not support streaming audio service following.

I expect more brands will be doing hybrid radio soon but I expect that the “chip shortage” we’ve been reading about, where the computer chips needed by automobiles are in short supply, will lengthen this hybrid radio rollout.

RW: Something NAB PILOT has been involved in, is testing the reception of all-digital AM radio in electric vehicles. Why is this important?
Layer: I’ve been privileged to work with a fine group of Xperi employees on an all-digital AM in electric vehicles project, most recently with Pooja Nair, an Xperi communications engineer who is my co-author for a paper on this subject in this year’s NAB Broadcast Engineering and Information Technology Conference Proceedings.

Also, a special thanks to Dave Kolesar of Hubbard Broadcasting for making all-digital AM station WWFD at 820 kHz in Frederick, Md., available for electric vehicle-related testing.

One of the topics covered in our BEITC paper is a comparison of the coverage of all-digital AM radio using both internal combustion engine or “ICE” vehicles and electric vehicles, or EVs. While only a limited amount of all-digital AM testing has been done in electric vehicles to date, the clear indication is that all-digital AM works well in electric vehicles and is much more resistant to the electrical noise generated by the motors than is analog AM.

This is important information for automakers as they make decisions affecting radio technology in electric vehicles.

RW: What else should engineers know about these topics and the work in radio that NAB PILOT is doing?
Layer: An interesting recent development is the installation and upgrading of the PILOT radio test bed into the Technology Lab at NAB’s new headquarters building at 1 M Street SE in Washington, D.C.

This test bed, built for PILOT by Cavell, Mertz & Associates, was housed at their office in Manassas, Va., prior to this move, and while in Manassas was used for a number of important projects including co-channel interference testing for all-digital AM radio and testing of FM-band HD Radio mode MP11 which adds an additional 25 kbps of throughput to digital FM radio signals.

Bringing this facility to the new NAB building will provide us with new opportunities to use the test bed for technology demonstrations to NAB members and others, and will allow NAB and PILOT to continue exploring radio technology and assisting in its development.

The post Layer Reiterates Importance of Good, Consistent Metadata appeared first on Radio World.

Click image to enlarge.

The author is executive director, broadcast technology at Xperi Corp.

As broadcasters, we often limit our perception of radio to audio programming. But we shouldn’t.

Jeff Detweiler

Today, Radio Data Systems (RDS) and HD Radio technology mean that data can be sent over the air through radio’s cost-effective and reliable, one-to-many delivery system. Each week, radio broadcast touches the lives of over 93% of the U.S. population, with no point-to-point connection, conveying simplex data effortlessly to a single unit or millions of devices.

Because it’s scalable, broadcasters can add millions of new data “listeners,” without increasing infrastructure costs or reducing existing service quality, for analog and digital broadcasts.

While FM analog RBDS services offer limited data, text or messaging, HD Radio technology enables digital audio programs and much higher levels of data services to automobiles, homes and portable devices. In other words: digital radio IoT.

Internet of Things

The Internet of Things, or IoT, has service providers who want to deliver content over a secure cost-effective platform, but security is a big concern.

At present, most connected devices allow bidirectional communication, with vulnerability to hacking. Configuration data, including personal information, may be exposed. Plus, there is the challenge of keeping those devices connected on in-home networks.

Unidirectional communication can mitigate these challenges: device applications can benefit from a one-way secure communication path.

Green initiatives

Recent regulations on Green House Gas (GHG) emissions mandate an energy shift from fossil fuels to an already oversubscribed electrical power grid, impacting electric energy pricing, billing and consumption. Radio is poised to play a significant role in this changing landscape.

On Aug. 5, 2021, President Joe Biden signed an executive order targeting that 50% of all automobiles be zero-emission by 2030, jump-starting a dramatic shift toward EVs. In 2020, California Governor Gavin Newsom signed an executive order banning all in-state sales of gasoline-fueled vehicles by 2035. In addition, the California Air Resources Board, Natural Gas (NG) plans to tighten rules on natural gas for home heating and hot water, effective in 2023.

Real-time demand/response

The proliferation of electric vehicles, and the shift from gas-fired heating to electric, will further burden an already overtaxed power grid. Constructing new generation plants, or adding battery storage, comes at a high cost to utilities, without addressing the variable nature of the load.

Creation of an intelligent demand/response network for managing power usage offers a solution. How? Providing real-time energy pricing to devices means they become “smarter” about energy cost, use and charging decisions — and this is where radio has a critical role to play.

The Consumer Technology Association has defined CTA-2045 as a modular communications interface (MCI) to facilitate communications with residential devices for applications such as energy management.

Among these are:

• Electric Vehicles (EV) charging systems
• Water Heaters
• Heating, Ventilating, and Air Conditioning (HVAC)
• Emergency shutdown of electricity and gas
• Smart City Lighting management and control
• Pool and spa pumps
• Autonomous vehicles
• Connected car

As the number of electric vehicles increases, peak use will exceed the design limits of the electric grid, overloading it with potentially disastrous consequences, including wildfires that cause loss of life and property. Rolling blackouts in California have become commonplace to reduce these risks.

Smart charging systems and utility control data mean EV chargers could manage charging times to avoid peak power demands, optimize charging costs. This requires tight collaboration between the auto industry, electricity providers, and data service companies, which is where radio can be indispensable: conveying pricing and control data. While this data distribution may not be exclusive to radio, it just may be the best fit due to security, reliability and cost concerns.

The competitive landscape

Sending 1 MB of data to 10,000 IoT devices requires 1 GB capacity for cellular, BUT only 1 MB for radio.

While 5G’s capacity and interconnectivity can offer advantages to connected cars and personal entertainment, 5G, like the power grid, may be oversubscribed before it reaches mass adoption. In 2020, connected cars and autonomous vehicles will generate 380 GB/hour to over 5 TB/hour of data, according to the Automotive Edge Computing Consortium.

A limitation on 5G networks is that they are yet to be fully deployed. 5G build-out in high population density and urban locations may be cost-effective for providers, but suburban and rural deployment will be a challenge given low population density and high rollout costs.

This is an opportunity for radio broadcasters, who offer broad reach through over 2,400 digital HD Radio stations, as well as scalability and reliability.

Today, through HD Radio data technology, stations are already transmitting real-time traffic and weather data directly to car navigation systems. Multiple automakers are working with HD Radio technology developer, Xperi Corp., to investigate, demonstrate and test additional data services, including software and ECU updates, map updates, navigation corrections, customer relationship management and more.

What is needed

Several components need to coalesce to achieve digital radio IoT. These include a content distribution system and a backend that enables service providers to connect to local radio stations or subscribers to provide content over available data bandwidth.

Radio stations could register to participate in data services and allow part of their data capacity to be used for services or applications. For example, an application provider (utility, city management, etc.) could have a data service or application that needs to communicate to their devices. The cloud distribution system would manage the data input and then route to the appropriately registered stations in the given market. Authentication, scheduling, and routing would happen automatically. The radio station simply has to configure their HD Radio Importer to open the available data ports. This data content distribution system has been prototyped and is operational in selected markets.

At the consumer end is a low-cost, low-power HD Radio-enabled IoT receiver module in the form of a plug-in card for an existing CTA-2045 compatible smart appliance or, ultimately, built-in to the appliance circuit board. The IoT module scans the band, detecting the application’s required data service. Once data is available, the HD Radio IoT device pulls the appropriate data from the digital broadcast and provides the content to the smart appliance application.

Xperi is testing this end-to-end system in several markets, gathering data on coverage and data reliability to create Quality of Service (QoS) metrics for these data applications. Xperi, together with the broadcast community and our development partners, looks forward to bolstering radio’s future with digital radio IoT, providing game-changing, cost-efficient and reliable data transmission services.

The post Radio Broadcasting and the Internet of Things appeared first on Radio World.

This article originally appeared in the Nov. 19, 2014, issue of Radio World and was posted on this website Nov. 26, 2014, a nice Thanksgiving treat. See More of John’s Schneider’s Roots of Radio.

A St. Louis Post-Dispatch employee reads the facsimile newspaper received over W9XZY. An RCA printer is shown. The black roller at the top contains the used carbon paper after the page has been printed. Wide World Photo, 1938.

In the beginning, there were newspapers.

And then radio arrived, challenging the newspapers’ journalistic monopoly.

At first, many newspapers fought the new competitor, refusing to print radio news or program schedules. But some went in the opposite direction, deciding to operate their own radio stations to augment their businesses. And finally, a few brave pioneering publications went even farther: They tried to deliver their newspapers via radio facsimile.

In the early 1930s, radio facsimile looked like the dream application for newspapers. They could use their own local radio stations to deliver newspapers directly to consumers during overnight hours. It would eliminate the cost of printing and distribution and shift those costs onto consumers, who would provide their own printers and paper.

A home user receives a Detroit News bulletin from WWJ on her Finch facsimile printer, 1938. Courtesy of the Detroit News archives.

This led several radio stations and newspapers to experiment with facsimile transmission during the late 1930s.

THE FINCH SYSTEM
The person most responsible for this technology was William G. H. Finch. He worked for the International News Service and set up their first teletype circuits between New York, Chicago and Havana. He became interested in facsimile machines and eventually amassed hundreds of patents.

In 1935, he established Finch Telecommunications Laboratories to build and market his system. Although RCA had already developed a facsimile system, it was only focused on its commercial possibilities. Finch envisioned the delivery of newspapers to the public via radio facsimile.

The Finch system circumvented RCA’s patents in several ways.

First, image details were transmitted by varying the amplitude of an audio tone, instead of its frequency.

An example of a news bulletin received on the Finch system.

Second, it recreated the image by generating an electric current at the tip of a stylus to trace the image onto thermally sensitive paper (the origins of the thermal paper still used by cash registers today). Synchronization between the transmitter and receiver used the 60 Hz line frequency. The Finch scanning head focused a pinpoint scanning spot on the document. A motor moved the scanner across the page while another motor advanced the page at the end of each scanning line. Low-frequency sync pulses were inserted at the end of each line. The result was an audio signal that could be fed into any conventional AM transmitter.

Finch receivers sold for $125 and were housed in a one-foot-square wooden box that could be connected to the speaker of any radio receiver. The images were drawn onto a continuous roll of thermal paper 5 inches wide that sold for one dollar and would last about a week. The process was slow, taking about 20 minutes to print a 12-inch page, but a timer was used to capture the transmissions from a local AM station during overnight hours. Six hours overnight was enough time to print a six-page, two-column news bulletin.

Several stations received FCC permission in 1937 and 1938 to experiment with the Finch system. The first was KSTP in St. Paul, Minn. It was followed by WHO in Des Moines, Iowa; WGH in Newport News, Va.; WOR in New York; WGN in Chicago; WHK in Cleveland; WSM in Nashville, Tenn.; and WWJ in Detroit.

McClatchy Newspapers published the Radio Bee over KFBK in Sacramento and KMJ in Fresno, Calif. It required a staff of seven to produce the radio newspaper, and McClatchy bought 100 Finch receivers to distribute to listeners.

RCA ADAPTS
RCA, sensing it had missed an opportunity, quickly adapted its system for use by broadcasters.

The RCA Radio Facsimile system was displayed in the RCA Pavilion at the New York World’s Fair, 1939.

The RCA system went into operation overnights on the St. Louis Post-Dispatch’s station KSD in St. Louis in 1937. By late the following year, the service moved to an experimental ultra-high-frequency station, W9XZY, transmitting on 31,600 kHz with 100 watts. It had a range of about 20 miles. By using a dedicated transmitter for facsimile, the transmissions could be made during daytime hours, and so the Post-Dispatch transmissions now took place at 2 p.m. Also, ultrahigh frequencies were less susceptible to radio static, which greatly disrupted the received image quality. RCA provided 15 receivers for the experiment, placing them at Washington University and in St. Louis area homes.

The receivers sold for $260 each and combined an ultra-high frequency receiver and facsimile printer into a single cabinet that had no controls or adjustments — the user simply kept the receiver supplied with rolls of carbon paper and white printing paper. RCA also demonstrated its facsimile system at the New York World’s Fair in 1939, transmitting special “Radiopress” bulletins daily over WOR.

CROSLEY GETS IN THE GAME
At the same world’s fair, Crosley Radio Corp. surprised everyone by introducing its own facsimile machine called the “Reado,” with two models selling for $60 and $80. (A timer to turn the unit overnight cost an additional $10.)

A Crosley Reado with a shortwave receiver and Finch facsimile printer (removed from its cabinet) at WWJ in Detroit, 1940. Courtesy of the Detroit News archives.

Powel Crosley had licensed the Finch technology and made some changes to reduce the cost. He produced an initial stock of 500 units and made plans to turn out up to 1,000 units a day. He began Reado facsimile transmissions during overnight hours over 500,000-watt WLW, which continued until 1942.

Most radio facsimile transmissions soon shifted from the AM band to the ultrahigh frequencies. About a dozen of these experimental stations were built, including the Milwaukee Journal station WTMJ, which transmitted over W9XAF.

Nonetheless, it soon became clear that radio facsimile was a technological dead end.

An engineer at W9XZY in St. Louis prepares an RCA scanner for the transmission of a news bulletin in 1938 in this photo from the author’s collection.

Despite all the promotion and hype, the public had neither asked for, nor cared about, the technology.

Receivers were expensive, suffered from frequent paper jams and outages, and were subject to content loss due to static.

To make matters worse, there were two incompatible standards fighting for market dominance.

Further, advertisers didn’t want to risk their money on the new medium, preferring the safety of traditional media.

The World War II paper shortages caused most facsimile stations to cease operations, and when the war was over, it was all but forgotten in the rush to build the new television industry. An attempt to bring it back on the FM band found no takers.

William Finch’s company went into bankruptcy in 1952, and RCA eventually took over many of his patents. Finch died in Florida in 1990 at the age of 93.

John Schneider is a lifelong radio history researcher. Write the author at jschneid93@gmail.com. See other photos from his collection. Click on the Roots of Radio tab atradioworld.comunder Columns.

The post A Look Back at the Radio Newspaper of the Air appeared first on Radio World.

Oh, by the way, about that NAL? You can toss that …

The Federal Communications Commission has canceled a notice of apparent liability for forfeiture issued to Carlos Lopez in relation to two FM translators in Texas.

As we reported earlier, the commission was planning a $3,000 penalty because the license renewal forms for the translators in Conroe and South Padre Island were due April 1 but not received until late May.

Now, the FCC says it had “overlooked the fact that the commission first issued licenses for the stations on May 14, 2021.” Thus it was impossible for Lopez to file for renewal by April 1.

“Given this and the fact that the licensee filed the renewal applications prior to expiration of the stations’ licenses, we find that cancellation of the NAL is appropriate,” it said.

Hey, it’s not called a notice of apparent liability for nuthin…

The post FCC Cancels NAL on Texas Translators appeared first on Radio World.

With nine weeks to go, IBC Show organizers have unveiled their plans to hold a hybrid event in December.

Following the reduction in COVID restrictions announced by the Dutch government earlier this month, organizers say they are “heading in the right direction” in terms of the physical event. “We are focusing on delivering an absolutely safe event,” CEO Mike Crimp told a media briefing.

While the rules around social distancing and wearing of masks have been relaxed, the IBC exhibition will include signs asking attendees to respect everyone’s preferences if they should want to continue with the measures.

The exhibition will also implement a “festival-style” perimeter fence, and include checks on vaccinations status, as well as recent COVID test status. Attendees from non-EU countries (such as the U.K. and U.S.) will be able to gain access to the Netherlands with a negative PCR test, but organizers suggest they check both their own government and the Dutch government’s websites in the run-up to the event.

In terms of the digital side of the event, this year’s content program will be free for everyone to access whether they are in Amsterdam or at home, the first time this has happened in the event’s history.

IBC Digital is a hybrid platform that will run in tandem with the live event, and enable users to watch content, schedule online meetings with exhibitors and other attendees, review exhibitor profiles, and invite colleagues to live meetings.

IBC 2021 takes place Dec. 3–6 at the RAI in Amsterdam.

 

The post “We Are Confident. We Are Not Complacent”: IBC Unveils Plans for Hybrid Event appeared first on Radio World.

Volkswagen Australia added DAB+ digital radio across most of its 2022 vehicle lineup.

The announcement came from industry body Commercial Radio Australia.

“All Volkswagen passenger and commercial vehicles in Australia will offer DAB+ with the exception of the base model grades of its van and ‘ute’ range,” CRA announced. It said models with DAB+ will include the Golf and T-Cross SUV.

[Read: Warner to Step Down at Commercial Radio Australia]

DAB+ is on air in five major metro markets and four other cities, and there are plans to add it to the Gold Coast.

CEO Joan Warner said the number of new vehicles in Australia with DAB+ had increased by 420,000 in the first half of 2021.

“The number of new vehicles sold with DAB+ was up by 25% in the first half of the year compared to the same period last year. This is good news for radio listeners who will benefit from the extra station choice, reliability and ease of use of digital technology,” she said in the announcement.

She added that 76% of new vehicles sold in Australia come with DAB+ from the factory and that 4.1 million new vehicles have been sold with DAB+ to June 2021.

 

The post VW Australia Expands Use of DAB+ appeared first on Radio World.

Microphone maker Shure is filling out the nooks and crannies of its microphone lineup. The latest is the MV7X.

While it has the readily recognizable shape of its well-known broadcast veteran cousin, the SM7B, the MV7X is aimed at the podcaster market, though Shure feels that broadcasters, streamers and musicians would also find it of interest.

[Check Out More Products at Radio World’s Products Section]

It is a dynamic cardioid mic with an XLR connector mounted on the rear. Its output is analog thus requiring a preamp or digital audio converter.

Shure specs the MV7X at 50 Hz–16 kHz. It has a metal body like the SM7B and its sister, the MV7. It ships with an adjustable yoke. Price: $179.

Send your new equipment news to radioworld@futurenet.com.

Info: www.shure.com

 

The post Shure Ships Podcast Microphone appeared first on Radio World.

Programs for a KNMC event this month as shown in a station social media post.

Student-run noncommercial radio stations still must adhere to the FCC’s rules. The case of a college station in Montana reminds us of that afresh.

The Audio Division of the Media Bureau said it has reached a consent decree with Montana State University Northern, the licensee of KNMC(FM) in Havre, Mont., over compliance with FCC rules for filing for license renewal and maintaining an online public file.

The license renewal should have been filed by Dec. 1, 2020, but was not filed until four months later. The commission also said the station had failed to place any issues and programs lists in its online public file before this April.

In the consent decree, the school stipulates that it violated the rules and will pay a penalty of $500. It will also put in place a compliance plan that makes sure the violations don’t happen again.

If it seems like the station is getting off easier than others might, it’s because the commission has a policy about certain cases that involve first-time violations by student-run NCE radio stations. In such situations it may offer a consent decree with terms like those that KNMC agreed to.

KNMC was started by English and speech instructor W.E. “Bill” Lisenby in the early 1950s and came to the FM dial in 1978.

The post College Station Signs FCC Consent Decree appeared first on Radio World.

Neutrik USA said Charlotte, N.C., will now be its centralized hub for the Americas.

It also is changing its name to reflect what it called a dramatic expansion. It will be called Neutrik Americas.

“The goal of this organizational shift is to provide centralized operation for the Americas, with the benefit of consolidated sales and support for the entire region,” it stated in the announcement, adding that it expects to be able to offer greater responsiveness for customers.

“As part of this expansion, Neutrik Americas now offers multilingual sales and support services.” It will offer

English, Spanish, Portuguese and French language support from its Charlotte headquarters.

The announcement was made by Peter Milbery, president of Neutrik Americas, who noted that the company moved to Charlotte in at a location near the Charlotte Douglas International Airport “to accommodate the logistics of this expanded territory.”

Neutrik Americas remains a  subsidiary of Neutrik AG and member of the Neutrik Group.

The post Neutrik USA Is Now Neutrik Americas appeared first on Radio World.

Learn how to find wahoo and kingfish using SiriusXM.

Meet SBE’s next president Andrea Cummis, the society’s first female president.

Find out why Xperi is interested in the Internet of Things.

And read about recent automation and traffic products from companies like Arrakis, ENCO, Smarts, BE, AEQ, Music1, NewsBoss, NextKast, WideOrbit and others.

Read the issue.

The post Inside the Sept. 29, 2021 Issue of Radio World appeared first on Radio World.

The Texas Association of Broadcasters is supporting a lawsuit that challenges a prohibition against using drones in newsgathering in that state.

The lawsuit, filed last November, is by a Texas news photographer. It challenges the constitutionality of Chapter 423 of the Texas Government Code, which “broadly prohibits the use of drones by journalists in public airspace, yet arbitrarily exempts other members of the public from those proscriptions,” the brief argues.

TAB said the law is a “speaker-based regulation” that discriminates against the press and violates the U.S. Constitution by harming the free flow of newsworthy information to the public.

TAB said it was joined in filing the amicus brief by the Reporters Committee for Freedom of the Press and 44 additional entities, including multiple station groups, the National Association of Broadcasters and other industry advocates.

“The brief outlines the public benefit of the technology when used for newsgathering, its similarity to other technologies such as news helicopters, and how the restrictions in state law constrain the devices’ use in newsgathering while permitting other, non-journalist speakers to deploy the devices at will.”

TAB said action in the case is expected this fall or winter.

Read the brief

 

The post Texas Broadcasters Speak Up Against Drone Restriction appeared first on Radio World.

A number of organizations that support EEO in broadcasting would like the FCC to consider nine proposals to help improve compliance and enforcement.

Their proposals are in a filing that was coordinated by the Multicultural Media, Telecom and Internet Council.

The FCC has open a further notice of proposed rulemaking in which it is taking comments about the collection of data to understand broadcast EEO trends by race and gender.

It wants fresh comments about the required collection of data on FCC Form 395-B, the broadcast station Annual Employment Report.

That form is intended to gather workforce composition data from broadcasters every year; but it has not been collected for two decades. The process was suspended in 2001 because of a legal ruling, and resumption was delayed in 2004 over issues involving confidentiality of the employment data. Those issues remain unresolved.

The EEO supporters told the FCC that resumption of data collection “would serve invaluable public purposes” but that this is not the only element that needs to be considered.

They asked the FCC to consider:

1. Requiring certifications that job postings preceded hiring decisions;
2. Auditing reform, “which includes increasing audit frequency and randomly selecting some audited units for more thorough review encompassing applicant interviewing and employee selection”;
3. Auditing of employment units that received EEOC probable cause determinations;
4. Opening “a fact-finding, non-content-based investigation … into the abysmal levels of minority employment in radio news”;
5. Providing whistleblower protections, including a confidential phone number and protections against retaliation;
6. Developing and disseminating compliance tools, such as an EEO Primer, Best Practices, FAQs and Model EEO Programs;
7. Extending EEO scrutiny to cover promotion, retention, training and mentoring;
8. Extending proactive EEO enforcement to high-tech companies, in cooperation with the EEOC; and
9. Consolidating all anti-discrimination compliance and regulatory enforcement (to include advertising, transactional, procurement and employment discrimination) in a new Civil Rights Section of the Employment Bureau.

The 38 organizations participating in the filing include the NAACP, Rainbow PUSH Coalition, the National Action Network, the Hispanic Federation and the National Bar Association.

The groups made particular note of a proposal to have the Enforcement Bureau examine whether a licensee, having been found to have violated the broad outreach elements of the EEO rule, may also have violated its core nondiscrimination obligation.

“It is hornbook law that EEO statistics should be considered as part of a tribunal’s consideration of whether a respondent company engaged in discrimination,” they wrote.

“As the commission has long held, excessive use of word-of-mouth recruitment by members of a station’s homogeneous staff is inherently discriminatory and could be disqualifying. If such a case arises, one piece of evidence that should be available to the Enforcement Bureau staff is data on the racial and gender composition of those whose ‘mouths’ are doing the ‘word of mouth’ recruitment.

“Broadcasting must not become the only industry in the country that is immune from the obligation to produce data that is useful to a finder of fact in determining whether an employer may have engaged in a discriminatory scheme.”

The post EEO Supporters Lay Out Their Wish List appeared first on Radio World.

This 40-watt amp from Monoprice has microSD and USB ports hidden under its lower lip.

Broadcast engineer Dan Slentz writes that when he was a teen working at WJER(AM/FM), the chief engineer had a speaker in each room wired with multiple 70-volt audio lines to a rotating switch and volume control. “You could listen to the AM station, FM station or any of the three production rooms,” he said.

Being 70 V, the audio quality wasn’t especially great, but when you were working after hours and you went into a room, you could monitor Air or what was going on. Dan says every station he has ever worked at had audio monitoring in the bathrooms. Even at CBS station WLVQ, “QFM” in Columbus, where the bathroom was in a public area down the hall, all occupants of the ninth floor of Nationwide Tower 2 could listen to QFM or Z-rock FM.

Dan recently visited the Monoprice website, www.monoprice.com. He loves it for its really good cables with lifetime warranty, and he says you can find other cool items on the site, like the old MCM Electronics used to have.

One such item was this 40-watt, wall-mount amplifier with a touchscreen, Bluetooth, auxiliary inputs and USB and microSD slots. The amp even has an infrared remote control. And it provides an FM receiver and stereo output.

Touchscreen controls

Dan notes that of course, this is made offshore. But all this comes in a compact footprint and costs only $120.

The top image shows the USB and microSD slots on the underside of the module, and the wiring connections are shown below.

Connectors on the Monoprice unit.

If it’s time to retire your old 70-volt speaker wiring or you’re thinking of adding a speaker monitor system, this module might be the solution. Consider mounting it in the breakroom, reception area or in your bathrooms. Use Monoprice product #36375. (As of mid-September the unit was listed as out of stock at the Monoprice website, with a November ETA.)

Sound Screw

If you’re planning new studio construction next year, you may want to discuss with your architect or acoustic consultant the newly released acoustic Sound Screw, developed in Sweden.

Imagine a screw, the “head” of which is separated from the threaded body with a coiled spring. It’s an inexpensive method of reducing vibration from joists into the drywall, as the spring dampens the vibration transfer.

Although it is only available in Sweden at the moment, Akoustos AB is approaching companies outside Sweden to license its technology.The company says that in lab tests, a 9 dB reduction of sound transfer was measured. This calculates to about half the perceived sound transferred using traditional drywall screws to hold sheet rock panels.

Check out www.akoustos.se.

Keep fans quiet

In an age when nearly everything seems to be in short supply, you may be tempted to substitute a fan in a piece of equipment. All fine and good, but contract engineer Stephanie Donnell has a caution if you’re installing a DC “brushless” fan in this situation. It could result in an EMC noise issue due to the current pulses generated by the driver circuit that operates the field coils of the fan motor.

EMC, electromagnetic compatibility, refers to the interaction of equipment with its electromagnetic environment and other devices. These electromagnetic fields could result in something that sounds like spark plug noise. You can correct this by adding a simple R/C filter on the fan’s “+” voltage lead.

Another tip involving muffin fans is to use models rated for 220 VAC but run them at 110. This is helpful in a situation where you need to improve ambient cooling around any equipment but where you don’t want a fan that produces a miniature hurricane or the noise associated with high-speed operation. Stephanie has used 220 V fans over the years to help cool everything from a very old computer to a Larcan-TTC TV translator.

Stephanie also saw Steve Tuzeneu’s recent tip about discouraging bees from nesting in satellite feed-horns. She adds that WD-40 brand spray lubricant works great for dealing with bees. We may not always have a can of flying insect spray, but who doesn’t have a can of WD-40 handy?

John Bisset, CPBE, has spent over 50 years in the broadcasting industry, and is in his 31st year writing Workbench. He handles western U.S. radio sales for the Telos Alliance and is a past recipient of the SBE’s Educator of the Year Award. Workbench submissions are encouraged and qualify for SBE recertification credit. Email johnpbisset@gmail.com. 

The post Workbench: Amp Up Your Bathroom Visits appeared first on Radio World.

This is one in a series of occasional articles about how to get the most out of popular radio broadcast products.

David Bialik consults to StreamGuys.

How the content might look on a mobile device.

When I was working for radio.com, producers for the news and sport stations all wanted a rewind feature on the mobile app.

These producers were hearing from listeners who enjoy the rewind functionality of live video platforms like TiVo and video on-demand platforms like Netflix, and they wanted similar functionality for their radio stations.

With rewind controls, a user can play the content they missed or replay content for clarity. Dr. Who would be perplexed with this timey-whimey issue.

StreamGuys kept this user experience in mind when they developed SGrewind. This service allows the listeners to use a “scrubbing feature” within the audio app.

The scrubbing can be configured to go back to the previous segment or to go back in timed increments.

If you are streaming a sport, you are giving the audience their own “instant replay.” Listeners of a talk show may want to re-listen to the last person who spoke. How many times have you listened to the news and want to hear a story again for clarification?

My favorite use is to “rewind” and hear the weather or traffic again.

Not to worry, you do not have to get Mr. Peabody and the Wayback machine. SGrewind is relatively easy to set up.

You do not need to be using StreamGuys as your live streaming CDN (though I am sure they would not mind if you already a customer). You can send them the same encoded source as your live stream.

StreamGuys will provide you a graphical user interface to configure how SGrewind will work and what your audience will be able to do.

They will then do their SGrewind magic, encoding the stream and sending it out.

The SGRewind Management Module is web-based.

They will work with your development team (if you have one) to enable the rewind feature on your player or they can provide a turnkey, rewind-capable player for your website.

Yes, I have simplified the process here, but SGrewind can add a nice feature for your streaming audience to use and make your streams look unique to potential advertisers. And isn’t that what it is all about?

Suggest a product to be featured in our “How to Get the Most Out of” series. Email radioworld@futurenet.com.

Related:

“Five Things You Didn’t Know You Could Do in Zetta”

“How to Get the Most Out of Your Remote Control”

 

 

The post How to Get the Most Out of SGrewind appeared first on Radio World.

Classic105 morning host Mike Mondo at the helm of the crystalClear console.

Kenya’s Radio Africa Group has taken a liking to Lawo equipment, recently choosing it for Kiss100 FM broadcast station and its Classic105 streaming station.

The Nairobi-based radio and TV broadcaster installed a Rɘlay PC-based virtual mixer at Kiss100 FM. After that proved successful, the company says, it turned back to Lawo to upgrade Classic105.

[See Our Who’s Buying What Page]

That led to the selection of a Lawo’s crystalClear “glass” touchscreen mixer. Included in that package are the VisTool virtual radio studio builder software and a Compact Engine, a 1RU mixing engine with AoIP audio interfaces and DSP audio processing. According to a release it was the first installation in East Africa of such equipment.

Lawo distributor and systems integrator BYCE Broadcast provided the equipment and services.

Radio Africa Group Technical Manager Philip Keter said, “We are happy with Lawo virtual consoles … We have had Kiss100 FM using Lawo Rɘlay mixing for more than one year now, and we have not experienced any downtime.”

Send news for Who’s Buying What to radioworld@futurenet.com.

He added, “We are even more excited about crystalClear; the presenters love its robustness, flexibility, and agility. It is not only easy to operate but actually helps enhance creativity!”

 

The post CrystalClear in Kenya appeared first on Radio World.

A broadcaster in Texas is facing a fine for not filing license renewal applications for two FM translators on time.

Carlos Lopez is licensee of the translators in Conroe and South Padre Island. License renewal forms were due by April 1 but were not received at the FCC until late May.

[Read: Expired Licenses Lead to $7,000 Forfeiture for FM Translator]

The commission says Lopez didn’t provide an explanation, so it has issued a notice of apparent liability for $3,000, which he has 30 days to pay or challenge.

Because he did file before the licenses actually expired, and because the FCC isn’t aware of any other problems, it said it plans to grant the renewal applications once the forfeiture proceeding is completed.

 

The post Two Texas Translators Face an FCC Penalty appeared first on Radio World.

Ryan Seacrest, one of the brightest stars in iHeartMedia’s talent constellation, has signed on for a new contract.

Describing him as an “unmatched creative talent,” the company said: “The three-year contract extends through Dec.31, 2025, during which time Seacrest will celebrate 30 years as one of the most recognized and respected names not just within iHeartMedia, but throughout the entire media and entertainment industry.”

In the announcement, Seacrest called the decision a “no-brainer.”

The agreement was negotiated by Jeff Refold, COO/CFO of Ryan Seacrest Enterprises, and Jonathan West of Latham & Watkins. Its value was not announced.

iHeart noted that Seacrest started in radio as a teenager at WSTR(FM) in Atlanta before he went to Los Angeles. “Since then, Seacrest has built a reputation as one of media’s most trusted voices, cultivating a genuine connection — and powerful relationships — with consumers, advertisers, and America’s biggest stars, and is a true brand ambassador for iHeartMedia.”

He will continue to host and produce his morning drive show for iHeartMedia’s 102.7 KIIS-FM, the syndicated “On Air with Ryan Seacrest” and “American Top 40 with Ryan Seacrest.”

iHeart says Seacrest is an important voice to its top management in planning major initiatives and tentpole events, and he will continue that advisory capacity.

In radio circles Seacrest also is known as a benefactor for children’s hospitals. His foundation builds broadcast media centers named Seacrest Studios in pediatric hospitals for patients to explore radio, TV and new media.

The post Seacrest Re-ups With iHeart, Calls It a “No Brainer” appeared first on Radio World.

Fig. 1: The Neewer NW-700 provides excellent performance and costs less than $15.

This article originally appeared in the Feb. 8, 2017, edition of Radio World Engineering Extra and was posted on this website Feb. 9, 2017.  If you like this content you should subscribe to Radio World Engineering Extra.

In two articles thus far (RW Engineering Extra, Aug. 10 and Oct. 19, 2016), we’ve traced the origins of electret condenser microphones to their externally-polarized ancestor, patented in 1916.

One hundred years later, modern materials and manufacturing have made electret condenser mikes cheap and plentiful — and with careful design electret audio performance can rival the best of their powered cousins. In this chapter, we’ll examine the anatomy of the circuitry following electrets and how they affect the sound output.

For our study, I picked a Neewer model NW-700 “Professional Studio Broadcasting & Recording Condenser Microphone,” which at the time of writing is listed at only $14.70 by the manufacturer, including a web shock mount and cable, shown in Fig. 1. Neewer was kind to let us share some of the NW-700 schematic, which we examine below.

Fig. 2: Inside the Neewer NW-700.

As discussed previously, all condenser microphones generate a small voltage as their diaphragm changes capacitance in an electric field, when moved by sound pressure waves.

Externally-polarized mikes charge the diaphragm/backplate condenser through a resistor from a source of 40 to 200 volts, as shown on the left in Fig. 3.

Because the capacitance is very low (around 50 picofarad, ±30 pF), the resistor forms an R/C network that rolls off the low frequencies. The resistor must have a value of hundreds of megaohms to avoid a cutoff in the bass range.

One advantage an electret has is its intrinsic charge, which eliminates the charging resistor, as shown on in Fig. 3. Either way, a fixed charge is maintained across the capacitor.

For a charge Q, the expression is: = 0 x 0

0 is the capsule capacitance, and 0 is the capsule capacitance.

The output voltage change of a condenser microphone is expressed as the fixed voltage times the relative change in capacity:

where Ct is the variation in capacity due to sound pressure.

It is not unusual for electret microphones to have a rated output of –40 dB relative to 1 volt measured at sound pressure of 1 Pascal (Pa), which is 94 dB SPL. The signal level produced by an electret element under these conditions is calculated to be:

An orchestra may produce an SPL of more than 105 dB, but loud musical instruments such as horns and drums could easily produce a local SPL of 115 dB when closely miked. That is 21 dB above the reference 1 Pascal, which multiplies the output to:

This voltage is an average of the signal envelope — but the peaks of the waveform are greater. Assuming the ratio between the signal peaks and the average is 10 dB, the peak signal level could reach:

That is arguably a big signal for the transimpedance amplifier!

Fig. 3: The basic parts of a condenser microphone. Left, using an external power supply, and right, a self-charged electret with the impedance converter. (Click here to enlarge.)

Let’s look at what may happen, beginning at the electret microphone as shown in the right diagram of Fig. 3. Nearly all electret microphone capsules have a junction-type field effect transistor (JFET) inside the case, to convert the extremely high impedance of the electret element to a useful value for the following circuitry.

Electric charges in JFETs flow through a semiconducting channel between source and drain terminals that is exclusively voltage-controlled. Unlike bipolar transistors, JFETs do not require a biasing current (although, as we will see they benefit from optimum terminal voltages). The JFET also has a potentially higher gain (transconductance) than the MOSFET, as well as lower flicker noise, making them well-suited to the microphone element’s weak signal.

CIRCUIT SIMULATION
To evaluate the microphone’s transimpedance amplifier and the following stages, I used circuit simulator software. It may be a little unconventional to do this study in software rather than with test instrumentation, but this came about because I was hand-drawing the internal circuits of several microphones and the simulator allowed me to check configuration of some unlabeled parts. (In one case, it helped me determine that a transistor’s emitter and collector had to be reversed and changed from NPN to PNP.)

The simulator I chose is Qucs, the “Quite Universal Circuit Simulator,” an open-source electronics circuit simulator software available on the Internet at http://qucs.sourceforge.net under GPL. Qucs supports a large list of analog and digital components with parameter values that can be applied to circuits to study DC voltages, AC performance, including noise and transient analysis, and more.

Fig. 4: Qucs circuit simulation of the impedance converter. (Click here to enlarge.)

Starting with the transimpedance converter, Qucs demonstrates some powerful analysis. Fig. 4 shows the circuit with an AC voltage source in substitution for the electret condenser. Note that a 100 picofarad capacitor is placed in series to represent the element’s real capacitance. The AC has been set to a 1 kHz sine wave at 0.25 volts peak. The meter icon shows a series current of 1.6 milliamps through the 2.2 kohm resistor tied to the 2N3685 JFET drain when supplied with 5 volts.

Two test points: “in” and “D_out” are shown in the Qucs chart to the right. (This is a transient measurement with DC voltages, so the AC simulation is deactivated.) The input signal is shown in red, producing a 0.25 volt sinusoid. The output at the JFET drain is shown in blue, with some gain but also with a large distortion to the waveform. The waveform is inverted, and the negative half is distorted because the signal input voltage drove the JFET’s gate positive, and an N-channel JFET is linear only for a range signal voltages that are negative, relative to the source terminal.

Fig. 5: Added components to operate the JFET gate at a more suitable voltage; the calculated waveform shows reduced distortion. (Click here to enlarge.)

One of the simplest ways to correct the signal voltage issue is by self-biasing, that is, raising the source voltage through as series resistor to ground, as shown in Fig. 5. R5 raises the voltage at the source terminal to 0.86V in this example, while a very large 1 gigohm resistor holds the gate voltage to 8.4mV. A bypass capacitor, C3, holds the voltage on R5 steady across the audio range. (These component values are for illustration and are not optimized.)

Self-biasing lowers the JFET’s distortion, and approximately doubles the gain in this example — but at the cost of a larger component count. Considering that electret microphone capsules often must be as small as possible, as well as low in cost, designers often forego these components. This illustrates a compromise for designers, but fortunately, high acoustic levels are probably not an issue in consumer applications, such as telephones, and they may be avoided to some extent in studio recordings by microphone placement.

Fig. 6: The audio path section of the NW-700 with a simulated electret microphone signal applied to the impedance converter and a phantom power supply. (Click here to enlarge.)

Fig. 6 shows part of the Neewer NW-700 microphone (as I traced it, less the voltage regulator section). Similar circuit designs are used in the many low-priced “studio” microphones on the market. In this case, the electret capsule’s JFET, J1, is pulled up to a regulated DC line (approximately 8.5 volts) and connected through an R/C high-pass network to a transistor stage T1, with a biphase output. This furnishes a balanced differential output for external studio preamps.

On the right, the NW-700 provides the balanced output through an XLR connector at the base of the mike. To “power” our example, a 48 volt DC battery is assumed, which is connected through resistors to Pins 2 and 3 of the XLR connector. A resistor value of 6.8k ohms is a standard value for 48 volt “phantom” systems, although many preamps supply lower voltages and may use lower resistor values.

The phantom power is connected through an R/C bypass network to a pair of emitter-follower transistors, T3 and T4, which provide approximately unity gain and have a low source impedance to the lines. The common point of the two transistors is tied to the voltage regulator, which provides the regulated and filtered DC for the input stages.

Fig. 7: Output at XLR Pins 2 and 3 as determined by Qucs with a 100mV input at 1 kHz. (Click here to enlarge.)

Qucs can provide a variety of AC systems analysis. In Fig. 7, a 0.1V (100mV) signal is applied through a 50 pF capacitor (simulating the assumed capacitance of a small-diaphragm electret element) to the JFET impedance converter. The output from Pins 2 and 3 of the XLR are charted as red and blue waveforms. The vertical scale is in volts, and the voltage offset, because of phantom power, runs at approximately 24.6V. In this simulation, there is slightly less output from Pin 2 than from Pin 3. However, this is unlikely to affect the noise rejection as that depends primarily on the common-mode rejection of the external preamplifier and not the normal-mode difference in signal between the lines.

IMPRESSIVE PERFORMANCE

Fig. 8: End-to-end frequency response from Pins 2 and 3; x-axis from 10 Hz to 20 kHz and y-axis in volts AC. (Click here to enlarge.)

Qucs supports predicted frequency response of the system, as shown in Fig. 8. As shown by the “ac simulation” data on Fig. 6, the simulator was configured for a logarithmic sweep from 1 Hz to 20 kHz in 2001 steps. Fig. 8 shows the sweep displayed from 10 Hz to 20 kHz. The frequency response is shown on linear vertical scale in volts, so a difference between 0.25V to 0.5V is ±3 dB.

It is apparent that the response is effectively flat from 100 Hz to the top of the range, and is down approximately 3 dB at 30 Hz. Of course, this excludes the frequency response of the electret microphone, and we know from the previous part of this series [Oct. 18, 2017, issue] that directional small diaphragm capsules have an intrinsic frequency tilt that is generally uncorrectable below 100 Hz due to limitations in acoustic filter techniques. However, this rolloff is offset by proximity effect at closer distances, so pickup of voices and instruments at a foot or so is reasonably well-balanced, tonally.

Recordings made with the NW-700 are generally quite good. On symphonic recordings made on high stands, there is noticeable low-frequency rolloff, but this was easily compensated with equalization during post-recording edit. The noise level of the NW-700 is not as good as expensive microphones (those costing 10 to 100X more) but it is acceptable, even for orchestral recording.

If you are interested in a sample recording with this microphone, visit this link on SoundCloud: https://soundcloud.com/john-kean-314785812/20160213-rachmaninov-3m26s

This 3.5-minute recording was made with the Washington Metropolitan Philharmonic Orchestra at the George Washington Masonic Temple auditorium in February 2016. It was recorded with a crossed-cardioid configuration in 24-bit/48 kHz sampling and transcoded to 16-bit/44.1 kHz in Audacity, with only LF equalization. The acoustics are not ideal, as the mics had to be placed on a low stand at the front of the seating area, but the recording gives you an idea of what the NW-700 can deliver.

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John Kean joined National Public Radio in 1980 after being chief engineer for a San Diego commercial FM station. In 1986 he joined Jules Cohen and Associates, and then Moffet, Larson and Johnson. He returned to NPR in 2004 to help establish NPR Labs and retired in 2015. Today he works with Cavell Mertz and Associates and performs audio consulting in private practice as Kean Consultants LLC.

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