Center Channel Removal
The first line of attack for software removal of vocal lines is called Center Channel Removal. Vocals are recorded in the studio in mono and placed equally in the right and left channels of the final mix, sounding like they are in the center between the speakers. Content that is identical in both channels can be removed from the file by software.
Almost all recordings have added reverb to the voices that is not possible to remove, so even after the center channel has been removed, there is a "ghost" of the original vocals remaining. This is usually not a problem, as it adds depth and color to your replacement vocals.
Targeted EQ
Often, instruments are also placed in the center channel, usually bass and drums. To prevent excessive loss of these instruments, our Vocal Removal tool uses targeted EQ to allow you to control the pitch range of the removal process, so if the voice is higher or lower than the instruments, much of the instrument sound remains.
It is not possible to apply center channel removal successfully to recordings that have not used the modern studio recording system, so recordings of live concerts, tracks recorded from from old records, and quite a few older CDs will not benefit from center channel removal. MP3s that do not have identical vocals in each channel also cannot use center channel removal. Our Vocal Removal tool allows you to determine immediately if your recording will benefit from center channel removal, or if you need to use targeted EQ.
When center channel removal is not effective, our Note Scrubber tool allows you to choose an area of pitch to be removed, for instance, the male vocal region or the female vocal region, or one specific pitch. Instrumentals in the same pitch area will also be removed, but often there is enough left to give a good backup to your voice. You can control the depth of the scrub, to get a good balance between removing the vocal line and preserving the instrumental backup.
Once the vocals have been reduced, the Mono to Stereo tool restores stereo quality to the recording. The Mono to Stereo converter does more than just make one channel into two channels. It modifies the two channels so that they sound as if they were recorded in stereo.
A small delay is added to the right channel; you can make it longer or shorter. Mono to Stereo can also add Equalization (EQ) to both channels, giving each channel a little bit different sound, which increases the stereo separation. There are several presets, and you can set each of the 10 frequency bands for each channel to determine which sounds you want to emphasize on each side. Each of the other effects can be applied to one channel at a time, so you can add a bit of echo to one channel and a little bit different echo to the other channel, creating the aural illusion of sound bouncing off different walls in its path to your ears.
RipEditBurn Plus and RipEditBurn can both remove vocals from recordings.