If you are working in an expensive studio built to reduce all unwanted noise, you won’t (or at least shouldn’t) have to worry about noise reduction techniques. However, it is inherent to home recording studios that there will likely be unwanted noise that you can’t control in your recordings. This includes signal hiss, guitar amp buzz and even other variables like street
noise coming from outside your home.
So while the best advice on noise is to not record it in the first place, when you can’t control it you can turn to a variety of noise reduction plugins to get rid of some of the bad sounds.
Previously, if you wanted to get rid of any noise, the only solution was to tackle the problem through a variety of mixing techniques, including noise gates and creative EQ. But this didn’t always get rid of all the unwanted noise, and often had the adverse effect of changing the original tone of the audio source.
If you are trying to eliminate noise that is present throughout your track, such as an amplifier buzz, you’ll want to a noise reducer. This would be in contrast to using plugins designed to eliminate sporadic clicks, pops, and other occasional unwanted sounds.
Perhaps the most popular of these types of noise reducers are graphical interface reducers, which present your track to you as a visual profile of your noise and allow you to control the reduction techniques with a variety of variables.
The other option is a fader based reducer, which does essentially the same thing but is a little more difficult without the visual aid, particularly if you are new to noise reduction. However, they also take up significantly less processing power on your CPU.
As mentioned above, there also are programs designed specifically to get rid of the anomalies in your recordings, such as a large pop in one of your tracks. These can come from a variety of sources, and previously engineers had to go through and manually remove each one. But new plugins are being produced that take on this task automatically, though there are not yet as many available as those products that reduce constant noise.
Even newer are spectral analyzers, which offer even more control over your noise reduction. Similar to the graphic analyzers above, these products present your audio in a visual form. However, you can select any part of your mix to edit and change. The process has been described as “unmixing,” and allows minute control over unwanted sounds.
Essentially, you isolate any part of your track that needs tweaking, and the spectral analyzers allow you to change or remove that part. This can range from a constant hum or hiss to a one-off pop in the middle of your song.
It should be reiterated, however, that you want to try to record as cleanly as possible in the first place for the best sound. But since this is not always possible, noise reducers are a great way to get rid of those unwanted sounds that get into your mix.