Issue link: https://digital.copcomm.com/i/24970
Audio Innovations Barefoot Sound’s MicroMain line of speakers combine a tweeter,woofer and subwoofer, all in one box. neous measurement of something that is objective. Loudness is subjective, so in order to simulate the perception of loudness, the measurement has to be integrated over a period of time. In fact, I like Dolby’s term of loudness estimation because it is like mea- suring color: you can break it down to the RGB levels, but ultimately every person sees blue a little differently.They same thing ap- plies to the perception of loudness. Every- one hears things differently.” Traditional VU meters, peak meters and other types of meters have their limitations by comparison to the ITU standard.“The thing with ITU metering is that it comes up with a single number, so there is no disput- ing the reading, or trying to decipher a range of numbers,” Carroll explains. “It’s a lot closer to getting us to numbers that everyone can agree correlates with the audio.The result, while still in the process of occurring, will hopefully be worldwide agreement that audio is measured with loudness meters.” In the past, audio requirements for many broadcast networks seemed to focus on one particular metadata parameter known as dialnorm, leading in many cases to confu- sion and incorrect results.“Much of the in- dustry has gravitated toward simply specify- ing a loudness target and requiring that content be delivered matching that target,” he says.“Certainly there are premium chan- nels that rely on the complete metadata system and it works well for them. How- ever, specifying a single target loudness value and then setting metadata parame- ters to fixed values also works and re- moves a serious layer of complexity for broadcasters challenged with handling con- tent that varies wildly in type and source. Plus, measuring loudness is universal.We are all the same: A Linear Acoustic LQ- 1000, a Dolby LM100, or a meter from any- one else that complies with BS.1770 will produce the same number when measuring the same content.” To add to the audio requirements of DTV is the evolution from two tracks to 12 or more audio tracks on a high definition videotape machine.This makes understand- ing audio metering and loudness more im- portant than ever.“That has impacted what I do,” says Carroll.“And now with the new SDI format at 3Gb per second, it can carry 32 channels of audio.There is no videotape machine that can record that many channels [yet], but with a server there is no reason why that can’t be done today.” With the ever-changing world of audio, video and DTV, Carroll’s ideas are sure to help improve audio overall. “It’s easy to rely on the idea that there is some device on the end of the chain that just fixes everything. That is one way of approaching it, but it doesn’t do much for the creative community. For me, there is a responsibility to preserve things, the 5.1 mix heard on the dub stage for instance, as best as possible.That does conflict in a way with the reality of watching a movie at home late at night where a pure theatrical mix is not really going to translate well.The idea of metering, measuring, and ad- justing will take you part of the way there, but metadata will probably take you the rest. That is important because if the content providers don’t understand this, then it will excite the sales of more processing and we will be back to NTSC audio. It’s a matter of us as an industry saving ourselves, and the clock continues to tick.” Symbolic offers the software-based Kyma and the hardware-based Pacarana. 38 Post • February 2011 www.postmagazine.com