EBU R 128 s1 — Loudness for Adverts, Promos and Idents

R 128 controls a programme with Programme Loudness and Maximum True Peak. Loudness Range, the measure that describes how much a mix moves, is derived from the distribution of Short-term loudness values taken over three-second windows.

The supplement explains its own reason for existing in one line: for commercials and promos that method “leaves too few data points”. A thirty-second advert simply does not run long enough for the statistic to mean anything. So short-form is controlled a different way — not by describing its range after the fact, but by capping how loud the loudest three seconds may be.

The document history records that version 2, January 2016, was a simplification that removed the Maximum Momentary Loudness option. A Maximum Momentary limit has therefore not been part of this recommendation for a decade.

Any source quoting a Momentary figure for adverts is quoting a superseded version. Version 3, August 2020, is the current one, and what it added was the two quality-control tolerances above — not a new limit.

The programme figure is unchanged from R 128, so a spot that measures −23.0 LUFS integrated is no less correct than it was. What s1 adds is a ceiling on the loudest sustained moment, and that is the constraint a dense advertising mix runs into first.

A spot can integrate correctly and still exceed −18.0 LUFS across its loudest three seconds — typically the end-line, the product shot, or the music hitting full arrangement under a voice. Meeting both numbers is a mix decision about where the peak energy sits, not a mastering decision taken afterwards.