My tip is that the plug-in included with RealBand is not sufficient by itself for most mixes, but read on...

Vocal removers can only work on stereo files. There's different ways to do it - the classic way is to reverse the polarity of one of the channels and then combine the channels into mono - this will cancel out whatever what was in "the middle". This will be mainly what the plug-in is doing. This works because (in theory) the lead vocal is effectively a mono recording panned into the center of the mix. It is also possible to digitally remove the central part of the stereo image - this may work better than the classic vocal removal technique in that you will be able to remove a "wider" chunk of the center of the mix if you need to, but you may end up with nasty digital artifacts. There are also various vocal removal plug-ins you can buy - luckily many of them can be demoed for free first so you can try them and see whether they will work for you. Another method of removing the "center" of a mix is to use a Dolby ProLogic surround decoder - you'd have to run the mix out of your computer and into a surround receiver to do this, which might be more complicated than you'd like (and the final results will still likely be no better without further processing).

Of course, many vocals are recorded with stereo echo/reverb which will not be fully removed. Also a lead vocal may consist of more than one track - ie, the lead vocal may have been overdubbed multiple times to give a fuller sound and those overdubs may be panned somewhat left and right and hence won't be removed.

Also, even if the vocal removal does work then everything that was in the middle of the mix will have been removed - in particular the snare and kick drum in most mixes and also the bass guitar. Of course, many vocal removal tools allow you to tune the effect somewhat by only including some frequencies, but the final results may still not be so great. You can use the "Lo Limit" and "Hi Limit" parameters in RealBand's Vocal Remover to limit the range of frequencies in which the vocal will be removed. However, with some tracks you will need to do a lot more work.

One technique that I have used is to grab a sample of the snare from a part of the song with no vocals (and preferably not much else going on) and pasting it on an adjacent track at all the appropriate moments in the song. Of course, that's a lot of work, as a typical song might have 200 or more snare hits, but it can make a big difference. You may need to do some EQ'ing on that snare sample to make it work better. It can be useful to also have a copy of the song, with no vocal cancellation, on adjacent tracks - you may be able to use part of these tracks in order to keep some of the drum fills or other elements that might otherwise be lost due to the vocal removal. This will require some creative mixing, but it can improve the final result significantly.

A little creative use of EQ may also help. You may find that using some parametric EQ can help to remove the "ghost" of a vocal. You may also be able to partially restore an instrument that has got lost in the mix by boosting a critical frequency with some finely tuned parametric EQ.

Note that if the file you are trying to remove the vocal from is an MP3 (or other "lossy" file) then you may have limited success because most MP3 encodings handle each channel separately and so the phase-reversal technique will not work as well as it would with a lossless file (eg, a WAV file). Lastly, if you use the "classic" method (polarity reversal) then the resulting file will be mono, but some digital vocal removers can preserve some stereo information.

Last edited by pinglis; 07/25/12 12:23 AM.