modifying audio files?

b2tf · 03-02-2007, 06:08 PM

Hey guys, Im after a bit of info/recommendation on how to go about messing with some audio files, just basic mp3s. The main thing Id love to be able to do is remove vocals etc from songs, I know its near on impossible to do once theyre mixed but Im wondering if there's any program I can get that can alter the levels etc to at least drown them out a bit. I listen to songs to hear the music, not the words, and sometimes Id love to be able to hear it a bit better.

I know its a big ask and not an easy thing to do but if anybody has any ideas/info on what to use to do it, it'd be very handy.

Cheers!

sfr rob · 03-02-2007, 06:15 PM

no, you cant remove vocals from a final mixdown, it IS impossible.
There are loads of programs that TRY and do it.. but usually stuffs all the levels up.
for a real easy program try GOLDWAVE, download it from download.com free etc etc...

b2tf · 03-02-2007, 06:34 PM

thanks rob, i know it is but even if i can just get close i'd be happy.

loxxr6 · 03-02-2007, 07:21 PM

Cool Edit Pro might help.

It can be found on torrent sites/p2p.

Damien · 03-02-2007, 07:22 PM

Okay, this may take a little bit of explaining, but I'll try to keep it simple. Once a song has been mixed down to stereo the only things you can do with it are as follows:

1. Reduce/remove the "centre material" ie. the stuff that is panned to dead centre of the mix (ie. both the left and right channels contain exactly the same level of the program material). The problem here is that vocals are very rarely the ONLY material in the centre of a mix; these days kick drum and bass guitar (two of the most important elements in a mix) are panned dead centre.
2. Reduce/remove/extend the "extreme left and right" material ie. the stuff that is panned full left or full right. Typically this stuff is doubletracked guitars, FX, synths, drum overheads (although these can contain some centre common program material as well), etc. In a stereo movie soundtrack this is the "atmos" track (ie. background noise and effects).

These two things are achieved through some tricky polarity inversion of the sound waves (commonly mistaken as "phase inversions" - 'phase' is the current position of the wave, not it's positive or negative situation). In fact, this is pretty much how early Quadrophonic and Dolby Surround formats managed to squeeze four channels of program material onto a two track medium (ie. VHS tape, Optical Film tracks, LP records) but still be compatible with stereo playback. I could go into it more, but it gets confusing.

The problem you will have is this: You can't do it with MP3s. Why? Because the MP3 format tends to eliminate a lot of the extreme stereo material as part of its compression. Remove the centre material and it'll begin to sound like you're listenning to an AM radio underneath water. MP3 relies on all information being there in order to trick the brain into hearing the whole stereo mix.

There are other options, such as Frequency Dependant Compression, but no matter what you do, you're going to be sacrificing other parts of the mix. Maybe try to find Instrumental mixes of songs, just about every band these days will produce an instrumental mix of a song or whole album to use for TV 'appearances' and the like, eventually these find their way to the surface.