New - TOA Metering VST Plugins

Posted: 19 February 2014

We've introduced three new metering plugins to the TOA libraries, including one that estimates loudness in 3D in a style similar to BS.1770. All of these meters are designed to work with 3D TOA streams.

The "TOA Meter" in the TOA Core library analyses the total decibel level in the TOA mix, and how that has been varying over the last three minutes. "TOA Meter - Signal" just provides a simple set of diagnostic indicators (i.e. lights) to show if signals are present.

"TOA Meter - Karma", in the TOA Decoding library, analyses the loudness of a TOA stream rather than simple level, using an algorithm based on ITU BS.1770 standard loudness (which is also the foundation of EBU R128 and ATSC A/85). It does not follow the algorithm strictly, as it has been modified to work with any 3D TOA mix (BS.1770 doesn't go beyond 5.1).

These plugins are designed to work with the other TOA plugins so that levels and loudness behave reasonably consistently as audio is converted between different formats. For instance, the Karma meter LUFS values calculated from the TOA mix are good estimates for the loudness after the mix is decoded, regardless of which TOA decoder and final speaker layout is to be used!

You can still apply a strict BS.1770 meter to the output in the cases where BS.1770 is defined (for instance stereo and 5.1, but not 7.1), and you probably should if you're metering for legal reasons. But, the estimate from the Karma meter will be pretty close, and this means you can get your levels about right just the once, rather than worrying about your stereo and 5.1 mixes separately!

We appreciate that metering isn't exactly "Rock & Roll" - but it's a useful tool.