Compare Files

Use this command to compare two files to each other and graph the differences between them. Select two files from the list (you must open at least two files before using this command). Note that the order the files are selected may make a slight difference in the comparison results. Similar files with missing pieces or gaps or delays cannot be compared accurately due to sudden changes in synchronization. Settings are listed below.

To compare two channels, use the Edit | Channel menu to select a channel, then use Copy and Paste New to extract each channel.

The Result tab shows the differences of the two files over time. The left side shows the dB axis and the difference is plotted as a solid gray graph. The right side is the time/speed difference, plotted as an aqua line. Files on a similar time scale have a horizonal line. Files that vary temporally will have a diagonal line.

A "difference score" gives the overall average difference. The higher the score, the greated the difference.

Compare Files Settings
Setting Description
From (Hz)
To (Hz)
Sets the frequency range to compare. Only frequencies within the From to To range are compared and all others are ignored. Use this setting to ignore low-end and high-end noises, such as hum, buzz, and audio compression artifacts.
Sync time (s) Sets the amount of time to match (or synchronize) the beginning of the two files. Use this setting to ignore any silence or noise (use Noise level setting below) at the beginning of the files and align them as closely as possible. Set it to zero to disable initial synchronization and compare the files without any initial time adjustment.
Noise level (dB) Sets the leading noise level to be considered silence when syncing the files. Audio is skipped at the beginning of the file while it is below this level. Use this to skip a fade in or a soft start of a file to get better initial synchronization.
Resynchronization method Sets the type of resynchronization method to use to realign the files in time. Resynchronization is necessary when files were recorded on different turntables or tape decks that have slightly different mechanical speeds.
  • Do not use resynchronization makes no attempt to realign the files in time if synchronization drifts off. Use this when you know the files are different and synchronization is not possible, such as comparing classical music to modern music.
  • Coarse resynchronization adjusts synchronization by a fraction of a second. This is fairly fast and gives good results.
  • Precise resynchronization adjusts synchronization to the closest individual sample when possible. This is the slowest method, but is recommended when files differ temporally. Note that it may not be possible to synchronize files with a time variation greater than 20%.