Tutorials Enterprise

Meeting Broadcast Loudness Requirements

Professional · ~20 min

Overview

Loudness compliance is one of the few areas of production governed by actual regulation, and it is measured rather than judged, so a mix that sounds right can still fail. The good news is that the rules are simple once the units make sense, and meeting them does not require compressing the life out of a programme. This guide covers what the measurements mean, how to hit a target while preserving dynamics, and the specific mistakes that produce failures.

What You Need

A loudness meter that measures to the standard your spec names
The delivery specification, which states the target and tolerance
A true peak limiter, used as a safety net rather than as a mixing tool
The full programme, since loudness is measured across the whole thing
Monitoring you trust at a consistent level
A measurement report to accompany delivery, if required

Steps

Understand the target is an average over the programme

Programme loudness is measured across the entire piece, not moment to moment. That means quiet passages and loud passages both contribute, and a programme can contain considerable dynamic range while still averaging to the required value. This is the fact that makes compliance compatible with good mixing.

Mix for the programme, then normalise

Mix so the material sounds right, then measure the whole programme and apply a single gain offset to bring the average to target. This is the correct approach and it preserves your balance decisions entirely. Compressing sections to chase the meter during mixing is what produces flat, fatiguing programmes.

Treat true peak as a separate limit

True peak measures the actual analogue level a converter will reconstruct, which can exceed the highest digital sample. Specs set a ceiling below zero for this reason. Meeting it is a limiter placed last in the chain, set to the required ceiling, not something you mix toward.

Watch dialogue level within the loudness target

Two programmes can measure identically while one has clearly audible dialogue and the other buries it under music and effects. Some specifications address this explicitly. All audiences notice it. Check that speech sits at a consistent, intelligible level rather than only that the programme measures correctly.

Measure the final file, not the timeline

Export processing, format conversion, and downmixing can all change measured loudness. Measure the actual deliverable, in the channel configuration being delivered, and generate the report from that file. A timeline measurement is an estimate of what you are delivering.

Check the downmix if one will be made

If a surround programme will be downmixed for stereo playback, that downmix can measure differently and can suffer phase cancellation. Where the spec requires both, check both. Where it does not, check anyway, because a large share of your audience will hear the downmix.

Theatrical Film vs. Streaming Delivery & Automated QC

Understanding the distinction between room-calibrated theatrical mixing, web monitoring, and streaming platform QC prevents unwanted audio processing during distribution:

Cinema Room Calibration (85 dB SPL): Cinema feature films do not use LUFS standards during mixing. In commercial theaters and mixing stages, speakers are calibrated using pink noise to Dolby Reference 85 dB SPL (Dolby 7). Mixing by ear at 85 dB ensures natural dynamic range across theater systems.
Theatrical (-27 LUFS) vs. Broadcast/Streaming (-24 LUFS): Theatrical features target -27 LUFS (±2 LUFS) (originally mandated by Netflix in 2018). Broadcast and OTT streaming platforms mandate -24 LUFS (±2 LUFS) (EBU R128 / ATSC A/85). Web and festival releases monitored on laptop speakers often sit around -13 LUFS.
Automated AI & Offshore QC Risks: Delivery specs allow a ±2 LUFS window (e.g., -22 to -26 LUFS for streaming), but you should aim within ±1 LUFS. Automated QC systems at streaming platforms run files through automated gates; out-of-spec mixes will be brickwalled, gain-adjusted, or hard-limited automatically.
True Peak Safety (-2 dBTP to -5 dBTP): While nominal true peak specs specify -2 dBTP, many streaming automated processors crush peaks down to -5 dBTP. Setting your final limiter ceiling to -5 dBTP prevents unexpected distortion from automated platform limiters.
Assembled Delivery Metering: Always measure the full, assembled final file (no reel breaks, 2-second heads/tails) using meters like iZotope Insight 2, Youlean Loudness Meter 2, or Waves WLM Plus before signing off on QC.

Pro Tips

Mix first, normalise once. Chasing the meter while mixing produces flat programmes.
Aim within ±1 LUFS of your target to pass automated streaming QC without aggressive gain-clipping.
True peak limiting goes last in the chain and is a safety net, not a loudness tool. Set to -5 dBTP for safety against streaming platform gates.
Measure the delivered file in the delivered channel configuration. Timeline measurements are estimates.
Watch dialogue intelligibility separately from the loudness number. They are not the same thing.
Keep the measurement report. It is evidence if a delivery is queried.

Knowledge Base

What You'll Learn

Loudness regulation exists for a specific historical reason and the measurements were designed to match perception. Below: what the units mean, and why compliance does not require compression.

Why Loudness Is Regulated and What the Units Mean

Loudness regulation exists because of a real and widely experienced problem: advertisements and channel changes producing sudden jumps in volume, because broadcasters were normalising to peak level rather than to perceived loudness.

Peak level measures the highest sample value and correlates poorly with how loud something sounds. A heavily compressed advertisement and a dynamic drama can share the same peak while differing enormously in perceived loudness, which is precisely what produced the complaints.

Loudness units were designed to match perception. The measurement applies a frequency weighting approximating human hearing sensitivity and integrates over time, producing a number that tracks how loud something actually seems. Programme loudness is that measurement across the whole piece.

True peak addresses a separate technical problem: the analogue waveform reconstructed from digital samples can exceed the highest sample value, so a file that never reaches full scale digitally can still clip on playback. Specs therefore set a ceiling comfortably below zero.

Together these mean a compliant programme is one that sounds consistent with everything else on the channel and does not distort on any playback path.

Why Compliance Does Not Require Compression

The persistent misconception is that hitting a loudness target means compressing everything, producing flat and fatiguing audio. It follows from confusing an average with a ceiling.

Programme loudness is an average across the whole programme. A piece with quiet passages and loud ones averages out, and the target says nothing about how much variation is permitted around that average. A drama with whispered dialogue and loud action can comply perfectly while retaining its full dynamic range.

What compliance does require is that the average lands on target and no peak exceeds the true peak ceiling. Both are achieved by mixing normally, measuring the finished programme, applying a single gain offset, and placing a limiter as a final safety net.

The historical reason for the confusion is that the previous regime normalised to peak, which genuinely did reward compression, making something as loud as possible within a peak ceiling meant reducing dynamics. Loudness normalisation removed that incentive entirely, and heavily compressed material now simply gets turned down.

Where This Fits

This guide covers one specific part of broadcast ingest. The wider picture, baseband, file-based, and IP ingest, metadata capture, QC gates, and never losing the source, is in Broadcast Media Ingest: How Enterprise Pipelines Actually Work, which frames the discipline as a whole and links out to the detailed guides underneath it, including this one. If you are starting from scratch rather than solving a specific problem, read that first and come back here.

FAQ

Q: Does meeting a loudness target mean I have to compress everything?
A: No. Programme loudness is an average across the whole piece, so quiet and loud passages both contribute and considerable dynamic range is compatible with compliance. Mix normally, measure the finished programme, and apply a single gain offset. Compressing to chase the meter is what produces flat, fatiguing audio.

Q: What is the difference between peak and true peak?
A: Peak measures the highest digital sample. True peak estimates the actual analogue level reconstructed on playback, which can exceed the highest sample, so a file that never hits full scale digitally can still clip on a converter. Specs set a true peak ceiling below zero for exactly this reason.

Q: Where should the true peak limiter go?
A: Last in the chain, set to the ceiling the spec requires, functioning as a safety net rather than as a loudness tool. If it is doing substantial work, something earlier in the mix is too hot. The limiter should catch occasional transients, not shape the programme.

Q: Should I measure the timeline or the exported file?
A: The exported file, in the channel configuration being delivered. Export processing, format conversion, and downmixing can all change measured loudness, so a timeline measurement is an estimate of what you will deliver rather than a measurement of it.