Volume Balancer is a shareware utility which adjusts the peak and average levels of WAV files so that they have the same perceived loudness. It is a 32 bit program that runs on all versions of Windows from Windows 98 onwards. It is primarily intended for use as a final step before burning a compilation CD from a variety of sources. Note that Volume Balancer works only on CD-format WAV files (ie. 44.1kHz, 16-bit, stereo). It does not work on MP3 files; if you wish to balance the loudness of these, it is necessary to convert them to WAV files first.
As many people have found to their frustration, simple normalization of the peak levels of WAV files does not make them sound equally loud. Perceived loudness is also influenced by the dynamic range of the file. To balance the loudness of a set of WAV files requires experimentation with varying degrees of dynamic range compression, and this can be very tedious.
Volume Balancer automates this process and is exceptionally easy to use. It is aimed squarely at the user who prefers not to have to bother with the intricacies of dynamic range compression and just wants an easy way to get their files sounding equally loud. Simply select the set of WAV files in question, choose a reference loudness level, and press the “Prepare & Balance” button. Volume Balancer then normalizes the peak levels of all the files and applies the appropriate amount of amplification and/or dynamic range compression to each of the files in order to bring their perceived loudness up to that of the reference. The results are written to new files with a name derived from the source files. Note: The source files are never modified.
More advanced features allow the user to set things such as the maximum allowed dynamic range compression, normalisation level, correlation between tracks whose relative loudness should not be altered, etc.