File failed QC: R128 Momentary

If your QC report shows R128 Momentary in red, a very short moment in your ad is too loud, even if the average loudness is fine.

R128 Momentary – reading the QC report

• The value next to R128 Momentary is the highest momentary loudness measured in the uploaded file, not the limit.
• This check only applies in some countries: currently Finland and Romania.
• To check whether your ad has a momentary limit, see Which technical specification should I use for my ad?

R128 Momentary – what it means

Audio Loudness measures the average over the whole ad. R128 ShortTerm measures 3-second windows. Momentary loudness is measured over a sliding 400-millisecond window, so it catches very short loud sounds, such as a sound effect, a sudden music hit or a shout.

The QC measures loudness to the EBU R128 standard.

R128 Momentary – likely cause

This is usually a file fault. Common causes:

• A sudden loud sound (impact, sound effect, music hit) goes over the limit for a moment.
• The mix was made for a country without a momentary limit.

R128 Momentary – fix

1. Click View Specs on your ad to see the momentary limit for your file.
2. Use a loudness meter that shows momentary loudness (EBU R128) to find the loud moment, and bring it down, for example with a limiter or by lowering the level, until it stays under the limit.
3. Check that Audio Loudness is still on target, re-export using the matching Export Guide, and upload the file again.

R128 Momentary – when to contact Customer Success

• You’ve exported the file using the specification shown by the View Specs link for the ad in your campaign, but it still fails this check.