I know this can be done, just not how exactly.

[solarbird]

…I even know how the math works. But that’s a long, long way from code, and besides, I know this already exists.

I have a live recording from last Saturday. On the left track, I have vocals + instruments. On the right track, I have just instruments. I want to subtract the instrument-only right track from the left track to get a clean, or at least reasonably clean, vocal track.

It doesn’t have to be perfect, because I’m going to put it back on top of the same instrumental track, I need to level some stuff and get rid of a couple of weird pumping-like artefacts and that’ll work 100x better with the mostly-clean vocals hanging out over there —>. People do the same audio math all the time, removing vocals for sampling, remixes, karaoke, stuff like that.

My digital audio workstation is Ardour running on Ubuntu Studio 8.04. I’d prefer to do this in Ardour, but if I have to install something else, I can. (And I have the Ubuntu Studio audio suite already installed. I also have an OSX box, and can boot the Ubuntu box into XP, if I must, but it’s kind of a pain in the ass to get things across the systems.) Google has not helped me.

Can I do this in Ardour? That would be optimal. I have Audacity running on the same Ubuntu box, tho’ I’ve never used it. I also have Rosegarden and it seems to run, and a bunch of other things I don’t know anything about yet because I haven’t tried them but none of them seem likely to do this. (Drum sequencer, stuff like that.)

If so, how? If not, what do I need?

Thanks in advance…

Mirrored from Crime and the Blog of Evil.

Comments

[quen-elf.livejournal.com]

If you can do it, the process should probably be as follows:

- Split the stereo into two mono tracks.
- Run phase invert filter on right track.
- Put both mono tracks in the same channel (centre if you can do that, or both left or whatever).
- Play it (obviously with both tracks together at same volume) to see if this seems to have worked. If so, save the mixed version as wav or whatever.

Looking at all those steps, this is one of the things that totally sounds like it ought to be possible in Audacity, but I haven't checked - does it have a phase invert filter? May depend on system and what plugins you have installed.

By the way I do use Audacity when I need to record audio, but find it absolutely horrible to use. On the other hand, it's not quite as horrible as the one time I tried to use Ardour :) [But obviously they are for different things.]

[solarbird]

That got 90% of it, which is enough for my purposes. I did it in Ardour. I also think that the vocal mic was picking up its own copy of the instrument, and that this naturally doesn't invert out. ;_; But it's good enough! Thanks ^_^

Audacity and Ardour are for the same thing -a Ardour just has a lot more capabilities, including some I need that Audacity doesn't have. (Audacity is Garage Band, Ardour is Pro Tools, more or less.) And Ardour's effort-to-learn curve is brutal. But I'm getting an album out of it.