Broadcast Delivery Standards: EBU R128, ATSC A/85 and Beyond

EBU R128 and ATSC A/85 both control perceived programme loudness, but they are not interchangeable labels for one universal target. The correct target, tolerance, channel format, true-peak ceiling and gating method must come from the broadcaster or distributor accepting the master.

R128 workflows commonly reference -23 LUFS, while ATSC A/85 workflows commonly reference -24 LKFS. Those figures are useful orientation points, not permission to ignore a network-specific delivery sheet.

Measure the Programme, Not a Convenient Excerpt

Integrated loudness must be measured across the complete programme segment defined by the specification. Reset the meter before the final pass, include all required content, and avoid measuring only the loud scenes or a dialogue-heavy reel.

Use a BS.1770-compliant meter with the correct channel layout. Check integrated loudness, loudness range, maximum short-term or momentary loudness where requested, and true peak. A sample-peak meter cannot replace an oversampled true-peak measurement.

• Confirm whether the target is LUFS or LKFS and which tolerance applies
• Confirm whether credits, bars, silence and commercial breaks belong in the measurement
• Measure every delivered language and channel format independently
• Document the meter version and standard used for the final pass

Dialogue Intelligence and Programme Gating

Some A/85-based specifications use dialogue intelligence or a dialogue-anchored measurement, while others request whole-programme loudness. Select the mode named in the specification; choosing the friendlier result creates a master that may fail automated QC.

Gating prevents long silence from dominating an integrated measurement, but it does not excuse unstable mixing. Watch short-term behaviour through scene changes so the programme remains comfortable even when the integrated value lands exactly on target.

True Peak, Dynamics and Versioning

True-peak compliance should be achieved without flattening the mix unnecessarily. Use gain structure, bus control and a final limiter conservatively, then remeasure after any codec preview because lossy encoding can create higher reconstructed peaks.

Stereo, 5.1 and alternate-language versions can produce different readings. Do not assume a compliant 5.1 master guarantees a compliant stereo downmix; phase interaction, centre contribution and surround fold-down can change both loudness and peak level.

Practical QC Checklist

• Correct delivery specification and programme boundary confirmed
• Full uninterrupted loudness pass completed
• True peak checked on every required master
• Stereo and surround versions measured separately
• Loudness report filenames match the delivered media

Build the final QC pass into the schedule. Loudness compliance is most reliable when it is verified from the exported master, not inferred from the live mix bus.