SCU Automates Lecture Capture with Array Mics and Extron Audio and Control Systems

Located in the heart of the Silicon Valley, Santa Clara University - SCU blends together a rich, Jesuit educational tradition with the innovations expected of an institute of higher learning. Recently, they began a multi-phase renovation of their academic buildings. Part of the project included upgraded AV systems designed to provide exceptional audio and video quality to support the learning process.

SCU partnered with AV integration firm Avidex to validate appropriate designs for each learning space and integrate the new AV systems. While Extron video, audio, and control products are widely deployed throughout the campus, this story focuses on the unique lecture capture system developed for the Leavey School of Business at Lucas Hall. The design provides automated directional tracking that allows the instructor to step from behind the lectern to teach and mentor student synergy. To enable instructor mobility and operator-free lecture capture, the design incorporates a Shure® MXA910 MicroFlex® Advance ceiling array microphone, two Sony® SRG300H/W PTZ cameras, and an Extron IPCP Pro 550 IP Link® Pro Control Processor.

Matching Extron’s DMP 128 Plus Series audio processor with Shure array mics and Sony PTZ cameras, all managed by the IP Link Pro control processor, has proven to be the absolute best solution for our classroom environments.

Joel Bennett, Manager of Media Services Group, Santa Clara University

Lecture Capture Evolution

Traditional lecture capture systems include one or more small surveillance-class cameras. Without an AV system operator in the classroom, the instructor must wear a wireless microphone and position tracker or remain fixed at the lectern to stay in the frame during recording. Student questions are often inaudible, requiring the instructor to repeat questions for the recording or pass around a handheld microphone. Employing a stationary microphone requires students to leave their seats to ask a question.

Use of audience boundary microphones were an alternative for lecture capture. However, they tend to pick up spurious sounds such as papers shuffling, the clicking keys on multiple laptops, and general noises like coughs and sneezes.

SCU’s solution solves all of these concerns. A couple of touches on the TouchLink Pro touchpanel’s screen turns on the AV system and activates lecture capture, allowing the instructor to begin the lesson without fuss or assistance from the support team. The system recognizes the presenter's location and follows their voice. As they move around the room, it automatically selects the best settings for each AV system component. Questions from any seat are also captured, eliminating the need to pass around a microphone or have students move closer to a stationary mic. This facilitates the natural exchange of information and interaction. The use of the ceiling-mounted array microphone greatly minimizes background noise that occurs with other microphone arrangements.

“It was important for us to leverage the most up-to-date recording technology as students increasingly rely on remote instruction and recorded lectures to stay ahead in today’s competitive fields,” said Nancy A. Cutler, Deputy CIO for Academic Technology at SCU. “Using Extron AV and control systems with the Shure array microphones helps us deliver on our promise of enhanced, connected learning environments for our students and user-friendly system operation for our faculty and staff.”

Automatic Audio/Camera Angle Tracking with Extron Pro Series Control System

An Extron IPCP Pro 550 IP Link Pro Control Processor is programmed to continuously monitor the sound levels from each of the MXA910’s eight microphones. The control processor identifies the direction of the best sound and immediately recalls the appropriate camera preset. Each preset activates the designated PTZ camera and sets the angle and zoom. Various camera presets are triggered as the instructor moves around the room or when a student asks a question. If no voices are discernable for eight seconds, the control processor defaults to a wide angle shot. The wide-angle view includes the lectern, the screens and whiteboards, and a portion of the seats.

“As a system designer and integrator, being the first to build AV systems that have such an incredibly rich feature set as the SCU classrooms was a challenge,” says Bill MacLeod, Design Engineer at Avidex. “Teaming with Extron and Shure allowed us to design the unique AV system in Lucas Hall that has brought higher learning technology experts to Santa Clara to examine and copy their automated lecture capture system.”

In rooms such as the pilot installation within Lucas 126, the Forbes Family Conference Center, and classroom Lucas 107, the design provides a complete AV signal switching and routing system based on an Extron DTP CrossPoint 4K Series scaling presentation matrix switcher. A confidence monitor is at the lectern, and display devices include a combination of two or more projection systems and LCD flat panel displays, depending on room size. Sources, such as a computer, document camera, or media player, and the AV equipment are split between the intermediate distribution frame — IDF rack in the back of the room and the lectern. Embedded in the lectern are Extron Cable Cubby® enclosures that offer convenient AV connectivity and power for the instructor’s laptop and other devices.

The IPCP Pro 550 control processor provides additional communication ports to supplement those available with the IPCP Pro processor built into the DTP CrossPoint® matrix switcher. Extron's powerful Global Configurator Professional - GC Pro software monitored external feedback using local variables, and conditional logic was applied through camera presets.

The instructor can manually operate the system using the Extron TLP Pro 1220TG 12" Tabletop TouchLink® Pro Touchpanel installed at the lectern. A screen can also be raised to allow the instructor to use a whiteboard while the other projection system provides content.

DMP 128 Plus with Dante Supports Array Microphones

The DMP 128 Plus C AT processor supports various audio tasks and signal routing. These include audio conferencing with AEC — acoustic echo cancellation, mixing and processing of the various microphones, audio sources output to the amplification system, and audio signal transmission to the room’s other systems. Extron's DSP Configurator Software facilitates audio DSP management of the DMP 128 Plus C AT processor. The software’s flexible graphical user environment simplifies the complex assignment of automatic mixing. Internal logic built into the MXA910 and the DMP 128 Plus Series processor ensure seamless, consistent sound without clipping.

The MicroFlex Advance ceiling array microphones connect to the DMP 128 Plus via Dante. The processor's Flex inputs allow the Dante channels from the MXA910 to utilize the AEC and input processing, along with mixing the program audio and other audio sources. For power, the array microphones operate on PoE from a network switch, and the rest use phantom power provided by the DMP 128 Plus. “When designing the Lucas Hall classrooms, we knew the Shure MX910 paired with the DMP 128 Plus audio processor was the missing piece for our automated lecture capture system, especially when camera tracking is controlled by Extron’s IPCP Pro 550 control processor,” says Sean K. Kennedy, Senior Media Systems Specialist at SCU.


Each room is ready for use when the instructor arrives. There is no need for university support staff to set up or operate the lecture capture system. Instructors enjoy being free of carrying or wearing devices and continually repeating student questions.

“It’s been a goal of mine to build rooms like these in Lucas Hall,” says Joel Bennett, Manager of the Media Services Group at SCU. “Matching Extron’s DMP 128 Plus Series audio processor with the Shure array mics and Sony PTZ cameras, all managed by the IP Link Pro control processor, has proven to be the absolute best solution for our classroom environments.”

Extron video, audio, and control products are widely deployed throughout the campus.

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