DK controls loudness27 August 2009
C4, RedBee and Grand Central Studios have chosen DK-Technologies’ loudness software to evaluate BCAP recommendations on audio levels in ads and idents.
The Broadcast Committee on Advertising Standards (BCAP) guidelines, which were published last year, advise broadcasters to look at the audio levels on commercials and idents following audience complaints that they are often too loud. BCAP recommends the use of loudness meters that incorporate International Telecommunications Union (ITU) specified algorithms BS.1770 and BS.1771 to measure loudness – something that traditional PPM and VU meters are incapable of doing.
At a recent briefing held at Grand Central Studios in London, 30 members of the UK Screen Association heard how C4, its sister channels, and channels such as Dave, Bravo, Living and Virgin 1 that broadcast from RedBee, have opted to use the ITU meter specifications in order to comply with the BCAP ruling. By the end of the summer all C4 servers will have migrated to RedBee and all non-programme material will have to meet the new specifications.
With C4 stating that it intends to adopt the same loudness criteria across all non-programme material – and with most other broadcasters indicating a similar mindset – it is becoming imperative for audio and video post production houses to invest in ITU recommended loudness meters.
For many companies, DK-Technologies’ new software is proving to be the answer because it incorporates the ITU recommended algorithms and also provides external logging to a PC. Developed in response to requests from key broadcasters and production houses such as Sky, ITV, the BBC and RAI in Italy, DK-Technologies’ loudness software can be incorporated into the company’s flagship MSD600M ++ audio meter, which is already in use at many broadcast and post production facilities, as well as into the new PT0760M waveform monitor and the stand-alone MSD100C loudness meter.
Grand Central has now upgraded five of its existing DK meters to incorporate the new loudness software and has also acquired an MSD100C loudness meter and a new MSD600M ++ audio meter with loudness measuring capability.
Raja Sehgal, Grand Central’s director of sound engineering, said: “With Ofcom getting complaints that adverts were too loud – and with our clients sometimes complaining that certain adverts sounded low – we needed to find a new level playing field. We have been working together with IMD and C4 to make sure readings are consistent and have tested the DK-Technologies meters with the ITU algorithm across hundreds of adverts. We have always used DK meters in our studios and transfer bay and, because DK meters are software upgradeable, choosing their system was the logical path for us to take. We have found that, with the ITU specification applied, the ad breaks sound much more even and some adverts with certain frequencies do not suffer in the way that they did when we used older loudness meters.”
Sehgal added that Grand Central has been hosting meetings on loudness for over two years now, reflecting the fact that broadcasters have all been looking closely at this issue.
“With broadcasters now starting to use the ITU spec, and with the possibility of mixes being rejected in the near future for not complying, we felt it was necessary to have a meeting with the Soho post houses to make them aware of the changes. By doing this we have been able to alert them to the issue so that they can get the relevant metering systems in place to be able to Quality Control the video and audio before playout.”
DK-Technologies loudness software is also in use at Independent Media Distribution (IMD), which digitally distributes commercials and programming to TV and radio broadcasters in the UK and Ireland. IMD has developed a custom delivery system that performs a quality control check on the soundtrack of advertisements to ensure they fall within the guidelines set by BCAP.
John Bolton, technical director of IMD, said: “We have been working closely with broadcasters and post production facilities to implement the new UK loudness standard for TV and, as a result, we have been very much involved in creating loudness values for commercials that fit within the BCAP guidelines.
“As part of this process we needed an audio meter that would enable us to measure loudness in line with the ITU specifications. We chose DK-Technologies MSD600M++ because it complied with these specifications and we therefore felt it was the ideal benchmark meter.”
DK-Technologies loudness software provides accurate loudness matching of audio from a number of different sources and offers a selection of working modes, including fast mode for realtime viewing of loudness, integrated mode for measuring the loudness of a recorded section or the complete recording, and gated mode for viewing loudness of audio material with long pauses, such as golf tournaments.
With selectable digital and analogue stereo inputs, the MSD600M++ displays left and right channel loudness as well as the summed loudness. It also delivers the information as a numeric readout. The meter uses the Loudness Units (LU) scale, covering a range from -18db to +9dB. It also features an audio vector oscilloscope, phase correlation meter displays, a full VGA colour display and VGA output for external display. Available in a variety of languages, it can be delivered with different scales to suit different broadcasters, while still maintaining the consistent loudness measurement as set out by the ITU.