ReplayGain

Measured gain tags even out playback so shuffled tracks no longer jump in level.

Related

Loudness NormalizationLUFSLoudness War

The question

Recordings differ widely in level, so shuffle jumps from deafening to silent. ReplayGain measures each track and writes a gain tag that playback applies automatically.

How it works

The tool measures loudness, historically with weighted RMS, now usually with EBU R128 LUFS, then compares it with a reference to derive a gain. Album gain can preserve relative levels inside an album. The player reads the tag and applies gain before output, limiting if needed. No audio data changes, only playback level.

Settings and practice

Use track mode for shuffle and album mode for whole albums. The target commonly sits near -18 LUFS. Enable clipping protection so gain cannot push peaks past full scale. Rescan after editing tags. Streaming services normalise on their own and ignore local tags.

What to listen for

Play an organ hymn beside a lute solo and hear the jump with gain on and off. With it on, check whether quiet detail survives and peaks flatten under limiting. Then listen inside one album, where loud and soft movements should keep their relationship.

Common misconceptions

ReplayGain does not rewrite files, only tags. It does not compress dynamics; track mode changes overall level, not the shape within a track. It does not make everything equally loud, since measurement error and limiting leave differences. It is not a mastering loudness standard.

Sources

• ReplayGain 的测量与标签机制，依公开规范与播放器文档核查，未抄文本
• EBU R128 响度测量的通识，依公开标准资料核查，未抄文本

Used for fact-checking only; all prose is original.