In the August issue of TV Technology, I covered the topic of monitoring and metering as a visual reference for audio mixers (“For Audio Monitoring, Seeing Is Believing”) This column continues the discussion of monitoring and the art of listening.

Critical listening in small and acoustically challenging spaces can be tricky at best and almost impossible in an OB van—almost. The problems range from poor speaker placement, improper speaker calibration and alignment, inadequate acoustic treatment in the OB van, frequency masking from extreme ambient noise including HVAC along with excessive chatter on intercom channels. Note: All of this can result in deceptive mixes and mixer fatigue.

IT’S ALL ABOUT DESIGN

Overcoming the myriad of problems associated with inherently deficient listening spaces begins with speaker designs for critical listening. Speaker design has generally been about originating all frequencies from the same location in space and time. This clearly means that the speaker, enclosure and acoustics should not change the direction and dispersion of the sound waves. There is no doubt about the difficulties of keeping the low and high frequencies constant in the horizontal and vertical planes because of the vast difference in the size of low and high frequency sound waves.

Many speaker manufacturers have adopted the term and principles of a shaped wave guide, which physically contours the speaker and/or enclosure to guide the propagation of the sound waves. The intended results are controlling the directivity and dispersion of the sound waves in an attempt to more focus the sound at the mixer while neutralizing reflections off the adjacent surfaces including walls, floor and ceiling as well as equipment. The downside is that a tighter focus of the sound waves may also result in a narrower “sweet spot.”

Multispeaker enclosures use separate transducer drivers for the high and low frequencies, which can lead to uneven reproduction, phase and distortion issues.

By locating the transducers as close as possible to each other and to the listener, this positioning helps the brain aurally perceive that there is a single point source. Point source is a relatively common speaker principle because of the advantages for phase coherence, while the ultimate point source design is coaxial speakers.

Coaxial speakers use a single driver to reproduce the high and low frequencies and tend to minimize some of these problems. According to Thomas Lund, senior technologist with Genelec, “From a perceptual point of view, organic (sound) sources above 300 Hz, like the human voice and musical instruments, radiate this way naturally.” As we know, the dominant sound in both film and broadcast is the human voice.

Even though coaxial speaker design has been around awhile, so have electrostatic and variations on ribbon type speakers. The inherent advantage to electrostatic speakers is that one diagram (like the coax speaker) uniformly drives the HF and LF, but electrostatic designs tend to be large and fragile and not really an option for OB use.

Ribbon transducers are based on the same design principles as typical magnetic- type moving coil speakers, but use different materials than typical tweeters. An interesting variation on ribbon designs is a concept called “Air Motion Transfer,” because AMT moves air differently and this design sounds different than typical tweeter designs. AMT is a folded diaphragm that moves air up to four times faster, resulting in quicker transient reproduction which, in turn, means more efficiency, less distortion and potentially higher frequency response.

NEAR-FIELD SPEAKERS

Speaker location has been a combination of room space and speaker design. In the last 30 years, I have seen improvements in the OB van audio space, but even with these improvements it still falls short in adequate soundfield reproduction and lack of proper acoustic treatment. Near-field speakers try to address these problems because near-field speakers, as the name implies, means the speakers are closer to the listener to minimize environmental acoustic coloration.

Generally, small speakers require a sub-woofer to reproduce the low frequencies, while mixing for film and broadcast require a low-frequency effect (LFE) speaker. I will suggest that this is the origin of some confusion between using the sub-woofer for bass management and the role of the subwoofer as the LFE.

The overall sonic experience of live sports audio for home listeners has improved with soundbars, but I believe that live sports sound tends to have an unnatural rumble because the sound mixer cannot properly hear full frequency 5.1 surround sound. Significantly, many up-processing devices push some of the sound into the LFE channel and a lot of this content that is up-mixed is definitely not LFE content. I’ll discuss this in a future column.

All listening rooms need to be tuned and virtually all manufacturers incorporate some sort of equalization and level contours with fixed set of switches to try and tame the speaker imperfections and room acoustics. I could not find another manufacturer that uses a dynamic software control in each monitor like Genelec. Software is used to configure, calibrate and control each monitor in the system for frequency response, level and time-of-flight or distance of the speakers from the listener.

Wave guide, coaxial and ribbon are viable speaker designs along with proper equalization and alignment, but now we must consider the size of the enclosure. Most OB vans have implemented sound monitoring within small rectangular spaces, but above speakers for immersive sound are going to be deceptive and problematic. Because of the nature of the OB van audio mix room, most speakers are relatively small and the addition of more speakers for immersive sound is tricky. Speaker placement is critical where the distance necessary for an accurate reference is a consideration.

The Ones speaker system by Genelec, unlike any others, offers a variation of point source and coaxial principles, which can deliver an accurate listening reference at a distance as little as 50 cm and an immersive impression in a 2 meter square.

Speaker sonics, high listening levels, distortion, unnatural imaging, all occur while the sound mixer must listen to a wide range of audio sources including program audio plus communications. There is no doubt all contribute to listener fatigue—a topic rarely discussed. Appropriate speaker design is a good start along with considering alternative workflow and ear training, all of which will facilitate immersive sound as the new standard for broadcasting. Immersive sound production is demanding in the OB Van, but not impossible—and it’s time to get ready.

Dennis Baxter has spent more than 35 years in live broadcasting contributing to hundreds of live events including sound design for nine Olympic Games. He can be reached atdbaxter@dennisbaxtersound.comor atwww.dennisbaxtersound.com.

BOTHELL, Wash.—IBC 2019 will be featuring the IP Showcase on its show floor, an education and demonstration pavilion that spotlights IP standards for real-time professional media applications, and is now looking for presentations to fill up its schedule during the five-day conference.

For this year’s edition of the IP Showcase, there will be a particular emphasis on JT-NM TR-1001-1 automation, as well as covering the SMPTE ST 2110, AES67 and AMWA NMOS standards.

End users, industry associates, solution providers and technology developers are all open to submit proposals for the showcase. Presentations can take many different forms, including tutorials, case studies, panel discussions, market and business case analysis, point-of-view or advocacy, and standards progress updates. There is also an expanded stage area this year, which will allow for presenting select hands-on technology demos. Product marketing presentations are discouraged.

“As broadcasters increasingly adopt and expand their commitment to IP implementations, the industry has come to rely on IP Showcase presentations as a valuable ongoing industry reference for media professionals worldwide,” said Brad Gilmer, IP Showcase executive director.

The deadline for submitting presentation proposals is July 12. To submit, or to find out more information, visit ipshowcase.org.

IBC 2019 will take place from Sept. 13-17 in Amsterdam. The IP Showcase, which will take place in room E106/E107, is sponsored by AES, AIMS, AMWA, the EBU, SMPTE and VSF.

Washington, D.C.. — Point Source Audio’s CO2 Confidence headsets played a large primary—and a critical secondary—role for double mic’ing at the 2019 AIPAC Policy Conference held at the Walter E. Washington Convention Center in Washington DC. Over 18,000 people attended the three-day conference and included members of Congress, students, and synagogue delegations. The guest speaker roster was massive (the AIPAC website lists over 400) and the audio needs were equally large with 120 channels of wireless mics being used. And, as typical, the expectations for fail safe reliability and sonic excellence with microphones were high.

AIPAC live interviews got “backup” from 40 redundancy headsets

To that end, audio supplier, Maryland Sound Industries (MSI) provided their client, Viva Creative, 40 of Point Source Audio’s CO2 Confidence headset mics for use with the Shure and Sennheiser RF systems that were utilized for the event. Given the amount of RF which, in addition to microphones, included IEMs, broadcast and security channels, the chance of being “stepped” on was very real and made frequency coordination and backup or redundancy options vital.

Robert Jones is the account manager for MSI and first tried the PSA mics at a demo and was impressed both with the sonic capability and the fact that he now had two identical microphones in one package. “In the past we’ve used two transmitters with a headset and with a lavalier mic as backup. If we lost a particular frequency, which can happen in an event this large, and needed to switch transmitters during the speech, the sound difference between the lav and headset is audible. With the Point Source Audio mics, the sound never changes and, on those occasions, where we do need to switch to the backup transmitter, the audience doesn’t notice. There is a sonic consistency we like.”

Jones also noted the increased speed and ease of mic’ing the talent with the PSA mics saying, “Once this thing gets rolling, it’s a constant process of removing the mic as the speaker leaves the stage, putting one on for the new speaker, and on and on. Anything that helps our techs with that process is much appreciated.”

Yvonne Ho, VP of sales & marketing at Point Source Audio, appreciates and understands the challenges of large-scale productions such as AIPAC and commented, “Beyond the audio quality aspect, our goal is to assist our customers in solving problems. If the tech crew can double mic speakers in half the time and ensure the live mic is fail-safe, then we are making real progress.”

The patent-pending CO2 Confidence Collection, a new class of wireless microphones, all have dual elements, each measuring a tiny 3mm that offers built-in redundancy. The CO2 mics also integrate two of the company’s important first-to-market features in miniature microphones: IP 57 waterproof rating, and the “unbreakable” headset boom bendable to 360° to bolster durability.

Point Source Audio will be showcasing the CO2 Confidence microphones for audio professionals at the upcoming InfoComm in Orlando, June 12 – 14, booth 5443. To learn more about Point Source Audio products, please visit www.point-sourceaudio.com

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About Maryland Sound
Founded in 1967 as a touring sound company, Maryland Sound has been an industry leader for over 40 years. While still maintaining a presence in the touring industry with artists such as Slash, Yanni, Seal, and other international artists, the company is now known as a leader in broadcast, sporting, and corporate events such as the Dew Action Sports Tour, multiple Presidential Inauguration Swearing In Ceremonies, as well as Inaugural Balls and, for 28 years, New Year’s Eve in Times Square. www.marylandsound.com

About Point Source Audio
Point Source Audio (@PSA_audio) manufactures and distributes worldwide their SERIES8, EMBRACE, and CONFIDENCE collection of miniature microphones — a unique line of headset, earworn and earmounted microphones known for their robust bendable boom and waterproof features. The company also holds two patents for the EMBRACE concealable microphone as well as the patent for the world’s first modular in-ear comms headset that is supporting the hearing health for audio, lighting and camera techs using headsets everywhere from sports to space. Founded in 2004, Point Source Audio is headquartered in Petaluma, California. For more information call (415) 226-1122 or visit www.point-sourceaudio.com. Follow the company on Twitter at www.twitter.com/PSA_audio.

WASHINGTON—It’s an exciting and challenging time to be a video professional! Government Video Expo returns to Washington, D.C., this November, and we are inviting potential speakers to submit presentation proposals.

We seek presentations targeting:

Corporate and enterprise video production
Live and event streaming for the government and public sector
Best business practices for creative professionals
Virtual, augmented and mixed reality
Aerial/UAV videography
Nonfiction filmmaking and documentary techniques
Visual radio – video for radio broadcasters
Video security
Distance learning
Video over IP
Sound production and post

Email a description of your proposed presentation, 300 words or less, to cclapp@nbmedia.com. Also include a brief description of your experience, background or qualifications.

Presentations are 30 to 45 minutes. Speakers receive free event registration. Speaker proposals are due by Sept. 22.

Government Video Expo, the Mid-Atlantic Region’s Premier Event, is designed for video, broadcast and AV professionals. The 22nd annual Government Video Expo will feature a full exhibit floor with numerous training options, free seminars, keynotes, networking opportunities, and five new educational pavilions.

This three-day event features a broad range of production, post production, streaming, display and delivery technologies on the exhibit floor, providing valuable information to media professionals working across multiple platforms for federal, state and local government, law enforcement, education, non-profits, and publicly funded institutions.

WASHINGTON—Those who would like to submit speaking proposals for the Broadcast Engineering and Information Technology Conference at the 2017 NAB Show are now eligible to do so, per a press release from the NAB. The NAB has also announced it will begin accepting proposals for all other conferences and signature sessions as of Sept. 22.

The BEITC is for broadcast engineers and technicians, contract engineers, broadcast equipment manufacturers, distributors, engineering consultants and R&D engineers. The conference offers technical papers on the challenges and opportunities in the broadcast industry.

NAB said in its press release that it is seeking “presenters with fresh ideas and unique perspectives on key trends and technologies driving the future of media and entertainment.” Topics that BEITC is looking to address include multiplatform distribution, emerging technologies, production and post-production workflows, social and mobile applications, new storytelling techniques, and changing advertising and business models.

The deadline for submission for all speaking proposals is going to be Oct. 31. Click here for more information.

The 2017 NAB Show will take place in Las Vegas from April 22-27.