EBU R128 Explained: The Standard for Broadcast Audio

EBU R128 is a recommendation developed by the European Broadcasting Union (EBU) to standardize audio loudness in broadcasting. It was introduced to solve the common annoyance of commercials suddenly blaring much louder than the television programs they interrupt.

The Core Metrics of EBU R128

To comply with EBU R128, audio professionals must measure and adhere to three primary parameters:

• Program Loudness (-23 LUFS): The integrated loudness of the entire program must be exactly -23 LUFS.
• Loudness Range (LRA): A statistical measure of the loudness variation across a program. It helps determine if dynamic compression is needed for comfortable home listening.
• Maximum True Peak (-1 dBTP): The absolute maximum peak level of the audio signal, measured using oversampling to catch inter-sample peaks that standard digital meters miss. EBU R128 specifies a maximum True Peak of -1 dBTP.

Why True Peak Matters

Traditional digital meters sample audio at a specific rate (e.g., 48 kHz). However, when the digital signal is converted back to analog for playback, the reconstructed wave can actually peak higher than the digital samples suggest. These are called "inter-sample peaks." True Peak metering oversamples the audio to predict and measure these analog peaks, ensuring no distortion occurs downstream.

EBU R128 in Modern Workflows

While EBU R128 was designed for broadcast, its principles have influenced the entire audio industry. Streaming services use variations of this standard for their normalization algorithms. When evaluating references using an app like LiveMarks, understanding the underlying LUFS and True Peak metrics helps you align your mixes with professional industry standards.