Meeting Report: Grand Junction Plaza Tour

Indiana Section members discuss the design and construction of the acoustic diffusion designed into the exterior of Grand Junction Plaza’s cafe building with park superintendent Chris McConnell.

Meeting Topic: Technical Tour of Westfield’s Grand Junction Plaza

Moderator Name: Jay Dill

Speaker Name: Russ Hopple, IMEG Corp; David Wright, IMEG Corp; Brian McCullagh, New Era Technologies; Chris McConnell, Westfield Parks & Rec

Other business or activities at the meeting: Brief announcements were made about membership, membership levels (associate vs. full member) and the change in name to the Indiana Section was officially announced.

Meeting Location: Grand Junction Plaza, Westfield, IN, USA

Summary

The Indiana Section toured Grand Junction Plaza, a unique, new six-acre park in Westfield with multiple zone-based audio systems and a number of performance venues, all with integrated wireless control. Russ Hopple and David Wright from the local engineering firm on the project opened our tour with a discussion of the planning and design of the park. The park was envisaged with an ice rink, a smaller amphitheater adjacent to a creek running through the park, a permanent structure for a café, and a large amphitheater with a band shell. The ability to use the park for a variety of events, or consolidate all technical functionality to support a single large concert was considered from the outset, along with maintaining a semblance of acoustic support from the surrounding buildings. In particular, special consideration was taken with the exterior design of the café situated opposite from the main stage, which features a faceted exterior stone wall facing the amphitheater to provide diffusion. Chris McConnell, the park superintendent, joined the discussion and explained that the park opted to purchase all audio systems, with the main stage featuring L-Acoustic line arrays with smaller center hangs and front fills, with Danley and Renkus-Heinz all-weather speakers distributed throughout the park. The system is managed via a Q-SYS platform for day-to-day operation, and Yamaha CL3 connected via Dante serves for larger shows, along with a full complement of analog lines. The FOH position is connected through subterranean conduit terminated in a buried cement electrical vault, which in turn houses a stainless steel outdoor electrical box populated with Neutrik weather-resistant connectors.

The constraints of municipal funding necessitated value engineering during the design phase. The most impactful change was the decision to defer construction of the band shell. The shell included an enclosed area which housed the central machine room for network and audio infrastructure across the park. Brian McCullagh from the audio integrator on the projected described the changes to cable runs, including increased distances, caused by the move of the machine room to the adjacent green room building. Knowing that the rack room may be relocated when the band shell is completed, the installers left cabling to allow wiring to be pulled back to the original location. Likewise, rigging for the center array was converted to a temporary solution due to the band shell change. The tour concluded with listening to the main amphitheater sound system.

Written By: Brett Leonard

Meeting Report: Section Meeting & CEDIA Tour

Central Indiana Audio Engineering Society at CEDIA Headquarters

Meeting Topic: CEDIA Headquarters Tour

Moderator Name: Jay Dill

Speaker Name: Steve Rissi, CEDIA

Other business or activities at the meeting: Brief announcements about membership renewal, bylaws voting, and tentative upcoming events.

Meeting Location: CEDIA Headquarters (Fishers, IN, USA)

Summary

The Central Indiana Section held its first in-person meeting since the start of the pandemic with a tour of CEDIA (Custom Electronics Design and Installation Association) headquarters in Fishers, IN. The event was generously sponsored by CEDIA and AES member Gavin Haverstick. Host Steve Rissi from CEDIA provided some context on the association, its focus on residential technology, and its dedication towards education and industry advancement.

The tour began in CEDIA’s experience center, which showcases cutting edge technology for the home, including advanced video, audio, lighting, power, and automation systems. The first room featured a large pair of Meridian Audio loudspeakers with onboard digital processing, a decoupled mid and high-frequency enclosure, and integrated class D amplifiers. The second room featured an on-wall audio-video installation with miniature line arrays from K-Array. Another highlight of the experience center was the adjacent glass-walled machine room, housing the center’s automation systems, media players, and amplifiers, as well as dedicated power with a massive toroidal isolation transformer.

The crown jewel of the experience center is CEDIA’s bespoke 9-seat home theatre, with a Barco projector and Dolby Atmos audio. The room includes fully isolated exterior shell and a 300-pound cement-core door to provide sufficient mass for acoustic isolation. Likewise, the projector is isolated in a dedicated projector booth and amplifiers, processors, and media players are all housed in the isolated machine room. Steve presented a variety of material from major motion pictures to showcase the audio and video clarity. This extended listening period allowed attendees to move throughout the space, listening to consistency from seat to seat and at the perimeter of the room. The room utilizes a distributed array of four subwoofers to homogenize low frequency response across the listening area, which was very apparent as one moved to the boundaries from the seating area.

The tour ended with walk through of CEDIA’s unique training facilities. Aside from typical classroom and workbench space, CEDIA headquarters features a number of “laboratories” for experimentation with home theatre setup. These rooms allow students to configure screens, loudspeakers, subwoofers, acoustic treatment, and even seating to measure the effects of changes in configuration. Another unique training area featured a variety of typical residential and light commercial construction wall segments for students to practice cable pulling and mounting of any variety of audio, video, or home automation devices.

Written By: Brett Leonard

Meeting Report: Strategies for Personal Monitoring

Meeting Topic: Strategies for Personal Monitoring

Moderator Name: Jay Dill

Speaker Name: Gino Sigismondi

Meeting Location: Online

The Central Indiana Section hosted Shure’s Gino Sigismondi for a presentation on personal or “in-ear” monitoring (IEM) systems.  The presentation began with an overview of IEM systems and a history of the technology.  As early as 1982 Marty Garcia built custom-fit earphones for stage use, and the first wireless IEM system was employed in the late 1980s using a simple FM transmitter.  By the late 90s, custom-built hardware gave way to commercial wireless IEM systems and “universal fit” earphones, greatly increasing IEM adoption.  The 2010s saw further advancement in diversity RF receivers, increased affordably, and personal mixing options.

Early in Gino’s overview of IEM system architecture, the topic of earphones was breached.  Despite seemingly endless earphone options, isolation was presented as the most significant consideration, as it provides the ability to hear a mix while maintaining a reasonable listening levels.  This point was reinforced later in the presentation when discussing the dangers of IEM listening at extreme levels, including issues with users removing one earphone.  Instead, Gino recommended the use of ambient mics or ambient headphone systems to provide audience feedback to IEM wearers.

From this broad system overview, Gino presented options for IEM system configuration, including receivers sharing a mix via a single transmitter, dual monophonic mixes from a single transmitter, and traditional stereo mixes. While stereo mixes provide a more realistic listener experience, both stereo and mono setups require tradeoffs.  Gino then presented a third option where each user receives two separate mono signals which can be balanced at the receiver, giving the user some local control of the mix.  The topic of distributed mixing was also introduced, along with potential pros and cons of such a system.  Case studies of scenarios for use of each of these options were presented, as well as example systems.

The presentation then shifted to the topic of RF management for IEMs.  Gino advocated for the use of inclusion groups, where wireless devices are segregated by type, with each using a different segment of available frequencies.  Similarly, wireless mic and IEMs units, and their antennas, should be physically isolated to reduce RF interference.  Proper antenna selection can also increase system effectiveness, with directional antennas being a significant way to reduce multipath dropouts.  Likewise, antenna combiners can help to reduce intermodulation issues within larger systems.

The presentation concluded with an audience Q&A.

Written by: Brett Leonard

Meeting Report: Exploring a Virtual Intercom System

Video from our last event is now posted on our YouTube page.

Meeting Topic: Exploring a Virtual Intercom System

Moderator Name: Jay Dill

Speaker Name: Hal Buttermore, Telos Alliance

Meeting Location: virtual (Zoom webinar)

Summary

The Central Indiana Section was joined by the Indianapolis section of the Society of Broadcast Engineers for a discussion of network-based intercom systems with Telos Alliance’s Hal Buttermore. The program began with a discussion about the paradigm shift involved in moving away from an intercom system based on dedicated hardware with a solution based on off-the-shelf computer and network hardware. Such a system feels similar to traditional intercom systems, with a variety of belt pack, desktop, and racked communication stations with typical party-line and talk-group configurations while taking advantage of current network technology, including AES67 integration. This creates a system that is lower in cost, easily scalable, and with greater end-user configurability.

An additional benefit of this system architecture is the ability to use existing VoIP technology for relatively simple interconnection between remote facilities. Telos employs the open standard OPUS codec for network communication between facilities. This wide area network can link remote production crews, separate affiliate studios, or even remote personnel to a central facility utilizing the same group and party lines. Included in this functionality is a “lite” mode for use with even typical residential wireless Internet and cellular modems. This capability was particularly useful through the pandemic, allowing production personnel working from home to share a reliable, dedicated intercom system.

Hal also highlighted the user configurability of such a system. In Telos’s Infinity intercom system, a simple drag-and-drop interface allows users to create party lines, talk groups, and direct connections within the system. A simple user interface allows receivers to be dropped into groups or party lines, or to create interruptible foldback (IFB) channels with near instant routing and availability. Finally, these routed groups, etc. can be dragged onto talk buttons for configuring belt packs, panels, or consoles as each user requires.

Finally, information was presented about Telos’s VIP system, which fully removes the requirement for hardware, replacing it with a single, dedicated intercom server. This Internet-connected server can then accommodate up to 16 virtual control panel/belt pack systems run through typical browsers, allowing operating system-agnostic usability with a simple link and password access system for users. This, combined with optional cloud-hosted servers and licensing based on virtual intercom quantity, allows the system to become scalable as needed while maintaining lower overall cost.

The program concluded with Q&A, moderated by section chair Jay Dill. The complete webinar is available for viewing on the CIS YouTube page: https://youtu.be/TwT2dTBLDh8

Written By: Brett Leonard

Meeting Report: Historical Development of the Unidyne

Meeting Topic: Historical Development of the Unidyne I, II, III

Moderator Name: Jay Dill & Nate Sparks

Speaker Name: Gino Sigismondi & Michael Pettersen, Shure Inc.

Meeting Location: virtual (YouTube: https://youtu.be/bvg6FYMRuAs)

Date: January 21, 2021

Summary

Shure’s Michael Pettersen and Gino Sigismondi joined the Central Indiana Section to dive into the storied history of the Unidyne dynamic microphone motor/capsule and the subsequent evolution that have shaped our industry.
Michael began the program by taking us back to the original electrical equivalent diagrams written in Benjamin Bauer’s notebook in 1937, describing what would become the “Uniphase Network” to create a single-capsule, directional dynamic microphone. The design was complimented by the work of designer Wesley Sharer, along with a little inspiration from the grill of the ’37 Oldsmobile Coupe Six, and was released as the Unidyne Model 55 in 1939.
The Unidyne II was first released within the Model 55S in 1951. The Unidyne II features the same performance with a size some 30% smaller than the original Unidyne capsule, thus the “S” nomenclature for small. The new design was oriented towards the television medium, which considered the original Model 55 to be somewhat obtrusive.
The Unidyne III Model 545 was released in 1959, touted as the “smallest cardioid dynamic microphone” ever. The Model 545 was end-addressed, and therefore had a more consistent polar pattern than similar and competing models of the era. This led to popularity with the burgeoning sound reinforcement industry, as the pattern’s consistency allowed for more gain before feedback. The Beatles were marquis users of the Model 545 with the A25B swivel mount.
As the Model 545 gained popularity on stage, Bob Carr worked on a line of Unidyne III-based microphones to appeal specifically to studios. This line, dubbed “Studio Microphones” (SM) consisted of microphones using the same capsules as existing mics, but with less reflective finishes, no switches, and included XLR connectors. The venerable Unydine III SM56 was released in 1964, with the SM58 released just two short years later. While not instant sales successes, the use of the SM56 at the Monterey Pop Festival by McCune Sound in 1967 yet again raised their profile in the live sound arena. The push as a live sound microphone line occurred more in the 1970s with their introduction to the performers and sound companies in Las Vegas, with artist such as Frank Sinatra becoming devoted users. Also of note was the introduction of the now-famed SM7 in 1972.
Following the history of the Unidyne series, Gino and Michael took audience questions, as well as providing a little “audio mythbusters” surrounding the Unidyne family.

Written By: Brett Leonard