Audio Basics
The exported files must strictly comply with the currently valid technical specifications for German Versions or Original Versions. The following information should generally be taken into account when delivering audio content.
Prior to distribution, every audio mix is reviewed by RTL Technology Quality Control. This process includes not only verification of compliance with loudness requirements but also an assessment of the balance between dialogue, music, and effects.
Audio mixes must not contain mutes, test tones, or sudden silences. If intentional silences are required for editorial reasons – for example, to remove content that is unsuitable for minors – they must be clearly documented. For multi-channel mixes, the downmix must be stereo-compatible and ensure correct reproduction across all playback devices.
The distribution of programme content in Germany is based on the loudness standard EBU R128. Productions delivered as German Version must be loudness-normalized accordingly. The objective is to ensure a consistent and comfortable loudness perception for viewers throughout the entire programme.
The average programme loudness, also referred to as Integrated Loudness, must be −23 LUFS. Due to the measurement tolerance of the QC equipment, a deviation of ±0.2 LU is permitted. At the same time, the digital peak level (True Peak) must not exceed −1 dBTP. To ensure balanced dynamics, the Loudness Range (LRA) should generally not exceed 20 LU.
In addition to these measurable parameters, the overall mix must be balanced. The complete audio mix should sound natural and must not contain unpleasant loudness jumps. Particular attention must be paid to consistency during transitions between programme elements and at the start of music, effects and dialogues. Programme openings and endings must not be disproportionately loud; opening titles and jingles must also be delivered at an appropriate level.
Dialogue plays a central role and must remain clearly intelligible at typical listening levels – regardless of whether the production is mono, stereo, or 5.1. Music and background noise must not impair speech intelligibility, as this area is a frequent source of viewer complaints.
Tracks 1 and 2 must contain the mix version in stereo as a standard requirement. Unused tracks must be muted (AES-0). All audio tracks must be synchronized with the picture.
For 5.1 mixes, the standardized channel assignment scheme applies:
L – R – C – LFE – Ls – Rs (corresponding to tracks 3 to 8). The exact assignment of all audio tracks must be clearly specified in the accompanying documentation. Deviations from the standard channel assignment are only permitted after prior agreement with RTL.
The exact assignment of the individual audio tracks can be found in the delivery specifications and varies depending on the agreed delivery profile and file format.