Volume Normalization

Access: MainMenu > File > Volume - Operates on selected rows, if rows are selected, or on all files if no rows are selected.

Multi-file Popup Menu > Volume - Operates on selected rows. Right-click Editor and choose "Volume" from the context menu.

Single-file Popup Menu - Operates on a single file. Right-click on any Volume cell.

MP3, M4A, and MP4 files that have been encoded with volume set too high or too low can be normalized by applying a command line program called AACgain.exe to the audio content. AACgain uses David Robinson's Replay Gain algorithm to calculate how loud the file sounds to the human ear, and increases or decreases the encoded volume accordingly. The audio itself is not altered.

Four normalization functions are supported in Library Clinic (refer to highlighted "Vol" column above):

1. Analyze Volume - Determine's the current volume level and places the result in the Volume Column.
2. Normalize Volume - Normalizes the volume and places the final volume level in the Volume Column. In most cases the original volume information is saved internally in the file and can be used to restore the original volume again using function 4) below. A small red triangle in the upper right corner of a volume cell denotes that normalization has been applied and that undo information is available.
3. Undo Normalization - Reverses a previous normalization and restores the original volume, if undo information was saved in the file when normalization was performed using function 2) above.
4. Remove Volume Data - Removes all analysis, normalization, and undo information from a file. Volume informaton is stored in an Ape tag at the end of MP3 files (field names 'REPLAYGAIN_TRACK_GAIN' and MP3GAIN_UNDO'), and in two free form strings in M4As and MP4s ('replaygain_track_gain' and 'replaygain_undo'). Executing this function removes these tag objects.

All volume levels are shown in decibels (dB).

The Volume Column is normally hidden from view by default. To expose it, check the "Volume (dB)" box on the Column Order & Visibility Panel. To pause or stop a multi-file normalization operation between files, click anywhere on the Editor's surface. This function does not support files with unicode names or paths.