Broadcast Beat Magazine September, 2015 - Page 73

Creating smarter loudness control systems

Because of this, products that help content creators monitor all of these parameters and bring mixes into compliance are more important than ever. Mixers require tools that automatically conform to different loudness standards—and do so transparently. This is particularly necessary for programs delivered to multiple standards for different broadcast territories with different standards.

One of the problems with Short-term correction is that it’s an absolute threshold (-18 LUFS, and in some specific specs occasionally -20 or -21 LUFS), which is quite low. When audio levels push the Short-term threshold hard, the resulting output can sound extremely crushed. A loudness control system must be specifically designed to spot these problems and correct them faster than real time while still allowing the mix to be as dynamic and transparent-sounding as possible.

As an example, iZotope’s RX Loudness Control supports EBU R128 s1 and it includes a Short-term compressor. An intelligent DSP built specifically for loudness analysis looks at all loudness parameters to ensure program material

passes Integrated, Short-term or Momentary, and True Peak compliance without crushing the dynamics in an audible way.

Attracting and holding the viewer’s attention will always be a key focus for content creators. But let’s do that artistically. While “gaming the system” may be part of the service for some, I believe that delivering the most accurate and best-sounding audio, without sonically assaulting the listener, will always be the best path forward.

Matt Hines is Product Manager for iZotope.


IBC Issue September 2015