Production

AM6 Radar Annoyance Meter

AM6 System 6000 SPL Radar

Pro audio is moving decisively away from the peak level based normalization method that has caused so much havoc with trailers in movie theaters.

The new and better mantra is to combine frequency weighting with an energy-integrated measure of sound, or equivalent continuous sound level, abbreviated Leq, and the level regulation of commercials and trailers in movie theaters is based on a measure of annoyance, also known as Leq(M).

TASA, MPAA, Dolby, DTS and others were involved in the definition of Leq(M), and the principle has since been adopted in several countries. Today, movie trailers and commercials are therefore generally under satisfactory control, though movies themselves may sometimes be annoyingly loud.

Recognizing requests from many System 6000 MKII users producing audio for broadcast as well as for cinema, we developed an Leq(M) based radar meter: The AM6. The radar represents an intuitive and efficient way of visualizing loudness or annoyance over time, while the integrated Leq(M) number indicates the status of the entire trailer or commercial with regard to regulatory limits.

AM6 System 6000 screenshot 2

When developing AM6, an important, new function was added to complement the integrated Leq(M) number: A proficient way of measuring peak level.

Sample-based peak level detection is long past its age of retirement, while true-peak assessment as defined by AES and ITU is trustworthy. A true-peak measure is demanding on the topology of the meter, and it requires more processing power than a futile sample-based meter, but it's a big improvement when it comes to predicting whether or not a film or music track can be distributed and reproduced without producing overload and distortion.

The AM6 meter includes true-peak measurement of all 5.1 channels, so you're the first to know if a production is likely to create downstream problems. Recall a preset based on Leq(M) limits of 82 dB or 85 dB, or go to the Preference page to scale AM6 to a level and a time resolution of your own choice.

 

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