Vocal Eliminator

Overview

The vocal eliminator is a device for removing vocals from stereo audio.  It would typically be used for karaoke applications (sing along with pre-recorded accompaniment music).  The technique for this audio trick is not new and involves using phase cancellation to remove vocals, which are usually recorded with equal level on both Left and Right channels.  For this reason, stereo audio is required.  Mono recordings or only Left or Right channels will not work.

A Fine Tune control is provided for those instances where the Left and Right channels are not properly time-aligned, such as when a tape head is misaligned.  This error in the recording can ruin the whole effect.  The Fine Tune is the Delay Time in samples ('z'=Audio Samples).  The delay time is expressed in samples to allow the finest control of the delay.

Controls

Active

When selected, the stereo audio is processed by the Vocal Eliminator.  This provides monaural audio with the vocal removal effect through both output channels.

Bypass

When selected, the audio at the inputs is supplied (unprocessed) at the outputs (still in stereo).

Fine Tune

Adjusts the time-alignment of the Left channel to the Right channel inputs.  The Right channel is fixed at 96 Samples ('z') and the Left channel is variable.  Normally, you should leave the Fine Tune set to 96.0z, so that both channels are delayed equally.  Fine Tune settings lower than 96.0z will delay the Left channel less than the Right channel.  Settings higher than 96.0z will delay the Left channel more than the Right channel.  For optimum performance, this control should be adjusted for each tape you play though the device.  CD sourced audio, although less likely to be misaligned, can still need Fine Tuning.

NOTE:  This algorithm will not remove a multi-mic choir from a recording.