Reducing noise

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Prevent noise

The best way to reduce noise in your recordings is to omit it entering your sound at all. For that task take care of the following:

Set the correct input level of your sound sources. Set it as high as possible to increase the dynamic distance of sound and noise, but as low as neccessary to prevent clipping.

If you have it at hand use a hardware limiter as long as Audacity cannot process sound in real-time. Personally, when recording a band I use a simple foot pedal limiter on the vocals, because these seem to be the most dynamic sound source. Instruments can be adjusted quite easily. When you have found the optimal levels, decrease them about a dB or two just to be sure. When actually performing, musicians tend to be a little bit louder than in rehearsal mode.

The noise tends to stay on the same low level, but the record source is dynamic and can change. Noise often comes up when a low signal is amplified and/or normalized. Normalizing and amplifing increases both the wanted signal and the unwanted noise. Therefore, initially setting the input as high as possible prevents noise to be heard later.

Shut every non-used sound channel and sound source. Mute non-used channels on your mixing board, switch off non-used amps, keyboards, and don't forget shut the door and the window. Especially in an home-recording environment, avoid switching lights or electric machines on or off during recording, because a spark can cause a knack on the track.

Delete noise

On virtually any recording you can find noise. It is not always neccessary to get rid of it completely. First-of-all, it is often audible only in very low-volume passages. Secondly, the not-too-picky listener will accommodate to the noise level of your recording if it stays on a roughly similar level throughout the material and if it's not too persistant to ignore. Sometimes, a completely silent passage e.g. between sequential parts of the programme can irritate a listener more than a constant low-level noise. Complete silence may disrupt the ambience of the material. So, you may wnat to change your attitude towards noise: It's not dirt that needs to be removed, but it's a natural part of all listening experience that has to be dealt with appropriately.