Measureing and Maintaining Loundess with the SAM-Q
MEASURING LOUDNESS ACROSS APPLICATIONS
LOUDNESS REMAINS THE SINGLE BIGGEST TOPIC OF VIEWER COMPLAINTS, AFFECTING EVERYTHING FROM TRADITIONAL BROADCAST THROUGH TO OTT AND PODCASTS.
Whether it’s the difference between the loudest and quietest parts within a single programme, between multiple programmes that contribute to channel output or the differences experienced when switching between channels, viewers should expect a consistent and uniform audio experience without having to reach for the remote.
Loudness measurement specifications from the ITU (ITU-R Recommendation BS.1770) along with recommendations from the EBU (EBU R128) and ATSC (A/85) have been created to help address this challenge and provide consistency throughout the broadcast chain and ultimately to the viewer at home.
Short and long-form content is increasingly subject to exacting broadcast delivery standards which stipulate target Loudness and True Peak values. Engineers need to ensure that these criteria are met and a loudness log can be created which can be used to validate the completed project.
ln a typical post-production environment, audio sources may be transported as SDl, AES or MADI. In this environment, the SAM-Q-SDI provides Momentary, Short-Term and Integrated Loudness measurements which are displayed using Loudness level meters and a numerical readout.
This same Loudness data can also be monitored over An Ethernet network and logged for later reference, enabling the finished project to be checked for compliance and a record kept.
Playout, Master Control and Transmission
Customer complaints about excessive loudness level may occur when commercials or programmes cause the viewer to continually adjust the volume on their television. Whether the culprit is a commercial which is perceived to be louder than everything else, a programme containing explosive effects or the transition between different programmes, it is important that the output of the TV channel is being monitored at Playout, Master Control or Transmission. As the last point in the broadcast chain before a programme Is ultimately distributed and delivered to the home, it is now becoming increasingly important for the control room to be equipped with the necessary tools to ensure all content meets the relevant loudness specification in order to guarantee the quality of service viewers expect.
Far from being a traditional rackmount audio monitor, the SAM-Q can simultaneously analyse mono, stereo or surround audio formats whilst also providing Short-Term, Momentary and Integrated loudness data over an Ethernet network. The logging of such data can be reviewed in the event of customer complaints and helping to identify any remedial action required to improve and maintain quality of service. When serving engineering positions in a Playout, Master Control or Transmission Suite, the SAM-Q is an ideal accompaniment to exiting video and audio signal analysis tools and combined loudness logging can be used to maintain consistent channel performance.
Although it can be impossible to anticipate the highs and lows within a live show or sporting event it is important that the Sound Engineer mixing the programme maintains target level across the duration of the production.
Equipped with the SAM-Q-SDI, audio engineers can periodically observe Loudness and True Peak readings, using loudness bar-graph and numerical displays. With its 8 independent loudness probes, the SAM-Q-SDI can measure and display the performance of a 5.1 audio mix and a 2.0 downmix simultaneously.
Whilst many mixing consoles are equipped with high resolution Audio channel meters, not all are capable of measuring loudness values or share those values over an Ethernet network for logging and display.
The SAM-Q-SDI is an ideal solution to loudness measurement and logging within a live broadcast production environment because it not only provides the sound engineer with a visual check of loudness performance but it also enables the loudness performance to be viewed remotely over an Ethernet network. During and after production rehearsals for a TV Show or event, the loudness history can be reviewed and if appropriate any potential areas of concern identified, allowing the sound engineer to anticipate and adjust the audio mix accordingly, helping to ensure that target loudness values are being adhered to without compromising the production.
A Look at Loudness requirements for traditional broadcast through to OTT and podcasts.
TSL's Insight Hub'A Look at Loudness'dives deep into the considerations, standards and examples of how customers keep on top of this extensive and very important topic.
“The TSL PAM2 MK2 gives us the power to monitor loudness for compliance with new broadcast standards, accurately meter audio for many sources and provide phase information. We are very pleased with the performance of the PAM2 MK2 units.”
Mr. Chu Cun, Head of Technical Operations at Beijing TV