Loudness standards for delivery: LUFS, true peak, BS.1770

Loudness delivery specs ask two things of your mix: an integrated loudness measured in LUFS over the whole programme, and a true peak ceiling measured in dBTP. Both are defined by ITU-R BS.1770, the measurement standard behind EBU R128 in Europe, ATSC A/85 in the US and most streaming platform specs.

Typical targets are around −23 LUFS integrated for European broadcast under EBU R128, and somewhere around −14 to −16 LUFS for many streaming platforms, with true peak ceilings commonly between −1 and −2 dBTP. Those numbers change and vary by distributor, so always check each platform's current spec sheet before you print a master. The rest of this guide explains what the numbers mean, how to measure them and how to correct a mix without wrecking it.

LUFS, LU and true peak in plain terms

LUFS (loudness units relative to full scale) is a measure of perceived loudness. It is not a peak meter. BS.1770 applies a frequency weighting that roughly matches how we hear, then averages energy over time. A mix with loud dialogue and quiet music can measure the same as one with quiet dialogue and loud music, even though they feel very different.

LU is a relative unit. One LU equals one dB of loudness change. If your film measures −20 LUFS and the target is −23, you are 3 LU hot.

There are three time windows you will see on meters:

• Momentary (400 ms): useful for watching moments in real time.
• Short-term (3 s): useful for checking scenes and sections.
• Integrated: the whole programme, with gating so silence and very quiet passages do not drag the average down. This is the number on the spec sheet.

True peak estimates the real peak of the analogue waveform after conversion, which can be higher than the highest sample value. A file that never touches 0 dBFS on a sample meter can still overshoot after decoding or lossy encoding. That is why specs ask for a true peak ceiling below 0, not just "no clipping".

Loudness range (LRA) describes how much the loudness moves over the programme. Some broadcasters cap it; most streaming platforms only advise on it.

Common targets, and why they differ

Broadcast standards were written to stop channels and adverts jumping in level. EBU R128 targets −23 LUFS integrated with a true peak maximum around −1 dBTP. North American broadcast under ATSC A/85 sits close by at −24 LKFS (LKFS and LUFS are the same scale).

Streaming platforms normalise playback, turning loud content down and sometimes quiet content up, so their recommended targets are louder, often in the −14 to −16 LUFS range for general content. Some measure dialogue loudness rather than full-programme loudness. Theatrical and festival screenings are usually not delivered to an LUFS figure at all; they are mixed to a calibrated room level.

The practical rule: mix for the most demanding destination first, keep that mix, and make delivery versions from it. Do not chase the loudest target and hope it normalises down nicely. Heavy limiting to hit a loud number is audible and cannot be undone by the platform turning you down.

If you are assembling a festival package, our festival deliverables checklist lists the audio files programmers usually expect.

How to measure your mix

These steps work in any editor or DAW with a BS.1770 meter.

1. Measure the full programme, from first frame of action to last frame, not a highlight. Integrated loudness needs the whole thing.
2. Exclude what the spec excludes. Some specs measure without bars and tone, slates or black. Trim them or set the meter range.
3. Read integrated, true peak and LRA together. Hitting the integrated number while overshooting true peak is still a failed delivery.
4. Listen at a fixed monitor level. Meters tell you the number; your ears tell you whether dialogue still sits right.
5. Write the readings down with the file name. A QC report you can show a distributor is worth more than a memory.

How to correct without damaging the mix

If you are off target, correct in this order.

1. Static gain first. If you are 3 LU hot, turn the master down 3 dB. Integrated loudness moves almost exactly with gain, and nothing about the mix changes.
2. Then deal with peaks. If lowering gain is enough, done. If raising gain to reach a louder target pushes true peaks over the ceiling, use a true-peak limiter on the master with gentle settings, and listen to transients.
3. Fix the mix, not the meter. If dialogue is buried and the music is carrying the loudness, a limiter will not help. Rebalance dialogue, music and effects, then measure again.
4. Re-measure the final file, not the timeline. Encoding can shift true peak.

Measuring and correcting in cinemaOS

cinemaOS includes a loudness preflight in its delivery path, measured according to ITU-R BS.1770-4.

Meters while mixing. In the Sequencer, open the SOUND console (⌘⌥S). The console carries loudness meters alongside channel strips, buses, sends and automation, so you can watch short-term loudness while you balance. A DIM −20 control lets you drop monitor level without touching the mix.

Preflight at delivery. In Finisher ▸ Deliver ▸ Export, the delivery panel runs a pre-flight check before writing the master ("CHECKING DELIVERY PRE-FLIGHT…"). The Delivery loudness card reports how the programme measures. If it is off target, Apply Correction applies the adjustment for you. Listen back afterwards and check the new reading, as you would after any gain change. Technical QC sits alongside it.

Delivery Bundle. If you need to prove what you shipped, Export Delivery Bundle writes the master with a checksum and a QC report. Masters are never overwritten; a second render becomes "Name 2".

One honest limit: cinemaOS does not include neural noise reduction or stem separation, so it cannot pull dialogue out of a finished mixed track. If your loudness problem is really a buried-dialogue problem, you need the separate dialogue, music and effects tracks.

FAQ

Is −14 LUFS the right target for everything online?

No. It is a common reference point for some streaming services, but platforms differ and update their guidance. Check each platform's current spec, and keep a dynamic master you can derive versions from.

What is the difference between LUFS and LKFS?

Nothing in practice. They are two names for the same BS.1770 measurement, used by EBU and ATSC respectively.

Why does my true peak go up after export?

Lossy encoding and sample rate conversion can create overshoots between samples. Leave headroom below the ceiling and measure the final encoded file.

Check your next master

Before your next delivery, run the integrated, true peak and LRA readings on the final file, whatever tool you use. If you want the measurement and correction built into the export step, try cinemaOS on a finished mix. The 60-day free trial needs no card.