ShortScale.org

I bought a £5 mic from PC world to use for this cover compilation. It's awful. Combined with my lame stock sound card the background noise makes it near unusable. I remembered a plug-in someone showed me when I was at uni that was surprisingly good for this sort of thing. You can either have it automatically detect the noise or you can use a 'learn' function and play it a sample of the noise so it knows what to elliminate. The idea is probably almost entirely phasing with a little EQ, but it's remarkably effective and definitely quite clever. I thought I'd make a thread about it in case anyone has similar problems and is put off recording with that setup or just carries on regardless. This is a relatively extreme example of noise but it could also be used for things that aren't quite so bad, or some background hum from an amp or whatever.

The clip in the spoiler is the same bit of recording played three times, each lasting about 16 seconds. It's not particularly well done as I knocked it together for the purposes of this post in a minute or so. There's a little noise in the reduced bit, and some guitar attack in that's removed. You can tidy that up a little with some tweaking but also consider that this is completely isolated and with a full mix around it it will also sound quite different.

1 - Unedited sample
2 - Sample with noise reduction
3 - What the noise reduction has taken out

what was the plugin?

That one was the one by Waves, which seems particularly good. There are quite a lot of free ones available, though.

The one I used looks like this.

The deal that's built into Audacity is pretty decent as well. It's under Effect -> Noise Removal. Like the Waves plugin, you can select a portion of the isolated noise and it'll try its damndest to remove it. It's not as advanced as the Waves version and you can get some pretty nasty artifacts if you're not careful, but I've used it to remove hiss from old bootleg tapes and such. My usual tactic is to use the NR pretty non-aggressively and then make some selective EQ cuts or run it through a lowpass filter.

Just for comparison's sake, I took your sample and overwrote the original first section with a quick dick-around using only the Audacity Noise Removal tool:
It's not quite as nice, but that was the best balance I could find.

check out reaFIR.

http://www.reaper.fm/reaplugs/

it's part of this pretty good vst suite. it's pretty damn good for nosie reduction.

these come with reaper but you can get 'em for free at the above link.