When the media operations center at the Public Broadcasting Service (PBS) sought a solution to comprehensively measure 5.1 loudness, it turned to the Sentinel Surround Sound Audio Monitor from Qualis Audio, a leading developer of professional audio measurement and monitoring instruments.
The Sentinel, with its extensive range of QoE measurements and ability to visualize both real-time and logged measurements, has significantly streamlined the center’s workflow, enabling staff to meet the network’s stringent loudness and quality control requirements enacted when it transitioned to HDTV and 5.1 surround sound.
PBS’s media operations center in Arlington, VA, receives, evaluates and produces the final preparation of all programming content scheduled to air on the broadcaster’s member stations. To ensure this material meets PBS’s strict Technical Operating Specifications, staff watches all programming in real time, comparing the final broadcast version to other processes. And, while PBS is not currently required by the CALM Act to meet loudness requirements because it does not run commercials, it still monitors loudness in accordance with the ITU1770.1 standard.
“A number of PBS members worked on implementing the CALM Act, and we believe it’s a service that is in the public’s best interest, so we make sure to evaluate every program that comes in and reject anything that does not meet our loudness guidelines,” says Steve Scheel, senior director, Media Operations Center, for PBS. “PBS distributes a large number of programs in surround sound and is very aware of the differences in loudness in 5.1 surround as opposed to stereo downmixes. Having the Sentinel at the media operations center has allowed us to meet our criteria on a variety of program materials and audio formats.”
In addition, the Sentinel’s downmix of 5.1 audio is carried out unattended with complete archiving of all measurements. This provides documentation for a Media Trouble Report (MTR) when a program fails to meet guidelines for submission. Scheel is also able to record an entire program, then cut it into various pieces and reassemble it for distribution on other platforms, using the Sentinel to measure loudness of individual segments after the fact. “No other device has done this for us,” he says. “It is amazing how much time it saves.”
Scheel and his team also rely on the Sentinel’s unique logging feature. The log is important because, any time a complaint comes up, PBS can go back to the originally ingested the content and verify that it was done correctly. Now that broadcasters are required to abide by the CALM Act, with potential fines of several thousands of dollars for non-compliance, the log is especially invaluable.
Prior to installing the Sentinel, Scheel and his team at PBS measured loudness using another product. The Sentinel enables PBS to view loudness in surround and stereo at the same time. Plus, with its continuous software upgrades, it has set the staff up for any future changes that may occur, such as the acceptance of ITU1770-2.
“Qualis Audio recently added a number of new features, especially now with talk that the CALM Act might also include the newer European Broadcasting Union’s ITU1770.2 regulation [which includes a loudness gate],” explained Scheel. “The Sentinel’s new features allow us to compare what would happen if the newer standard came in and allows us to look at the European standards that are being used as well. It’s a very versatile meter. For us, it’s the perfect instrument and it meets all of our needs and is an investment we needed to make.”
Steve Wynn, director, engineering and maintenance, Media Operations Center, PBS, echoes Scheel’s sentiments, explaining how crucial it has been for the broadcaster to find a solution that works with the center’s existing equipment.
“It is so refreshing to have a critical component, such as the Sentinel, that’s so well designed,” says Wynn. “It has its embedded operating system, talks nicely on the Web and it’s a controlled environment, so it’s more secure. Plus, we have always received positive support from Qualis Audio. They were very helpful with the installation and setup, and continue to be as changes come in. The issue of loudness isn’t over and it has been worth the initial investment to have a solution that will grow with the changes and the issues.”
The Sentinel Surround Sound Audio Monitor measures, monitors and logs loudness and virtually every other parameter necessary to ensure optimum audio reaches broadcast viewers. Its measurement and logging verify and document CALM Act compliance, conforming fully to all ITU BS1770, ATSC, FCC and EBU requirements. Any deviation outside of the allowed range automatically generates alarms to the user’s choice of SNMP, email or GPI. The Sentinel also measures, displays, logs and alarms all pertinent audio parameters, such as the new downmix loudness capability described above, downmix compatibility, hum, balance and other parameters required for quantifying audio quality.
