xtra.audio

EBU R128 ​

Loudness normalization based on the EBU R128 broadcast standard.

What is EBU R128? ​

EBU R128 is a loudness recommendation published by the European Broadcasting Union. It defines how to measure perceived loudness using LUFS (Loudness Units Full Scale) instead of traditional peak-based metering.

Traditional peak meters measure signal amplitude but not how loud audio sounds to the human ear. Two tracks at the same peak level can sound drastically different in volume. EBU R128 solves this by measuring integrated loudness over time.

Why Loudness Normalization Matters ​

Without normalization:

  • Volume jumps between tracks (different mastering levels)
  • Listeners adjust volume constantly or leave
  • Manual gain adjustments are time-consuming and inconsistent
  • Audio from different sources (CDs, streaming rips, vinyl transfers) varies wildly

With EBU R128:

  • Consistent loudness across all content
  • Smoother listening experience
  • No manual track-by-track adjustments needed

How xtra audio Implements It ​

The system measures the integrated loudness of each audio file and calculates the gain adjustment needed to reach the target LUFS. This correction is applied during playback without modifying the original file.

Processing chain:

Audio → Gap Killer → EBU R128 → StereoTool → Encoder

Included in All Plans ​

Consistent broadcast audio is fundamental, not a premium add-on. Every station—regardless of budget—deserves professional-grade loudness normalization. xtra audio includes EBU R128 at no additional cost in all plans.

Configuration ​

SettingRangeDefault
EnabledOn/OffOff
Target LUFS-44 to 0 LUFS-16 LUFS
Use CaseTarget LUFSNotes
Internet radio-14 to -16 LUFSStandard for web streaming
FM broadcast-18 LUFSBefore additional processing
Podcasts-16 LUFSSpotify and Apple Podcasts standard
Streaming platforms-14 LUFSYouTube, Spotify target
Broadcast TV (EBU spec)-23 LUFSEuropean broadcast standard

For in-store, retail, or background music applications, use -14 to -16 LUFS. The actual playback volume is controlled at the amplifier or playback device—LUFS ensures consistent loudness between tracks, not the room volume.

Enable Normalization ​

  1. Navigate to Station → Settings → Audio Processing
  2. Enable EBU R128 Normalization
  3. Set the target LUFS value
  4. Save changes

Normalization applies in real-time during playback. Existing files do not need to be re-uploaded.

FAQ ​

What is EBU R128? ​

EBU R128 is the European Broadcasting Union's loudness recommendation. It specifies how to measure and normalize audio loudness using LUFS (Loudness Units Full Scale) instead of peak levels, ensuring consistent volume across different audio sources.

What LUFS level should I use for radio? ​

For internet radio, use -14 to -16 LUFS. This provides good loudness while maintaining dynamic range. For FM broadcast, -18 LUFS is typical before additional processing by the transmitter.

Does loudness normalization reduce audio quality? ​

No. EBU R128 normalization applies gain adjustments without compression or limiting. The original dynamic range is preserved—only the overall level changes.

How is LUFS different from dB? ​

LUFS measures perceived loudness over time, accounting for how human hearing works. dB (decibels) measures signal amplitude. Two tracks at the same dB peak can have different LUFS values because LUFS considers frequency weighting and duration.

Should I normalize before or after audio processing? ​

In xtra audio, the processing chain is: EBU R128 → Sound-Processing (e.g. StereoTool) → Encoder. Normalization happens before final processing to ensure consistent input levels for any additional audio enhancement.