If you are happy with your recording, you can use Audacity to tweak it. It’s always a good idea to cut away unused silence (or wrong tones) at the beginning and end.
Two common post-processing steps are normalizing and noise reduction.
This is a trick that will make the sound of your recording as loud as possible, without distorting it.
If you record multiple pieces to put them on a CD, for example, then it’s important that each track is not significantly louder or softer than the others, otherwise the person listening will have to dial the volume knob up and down with every new track.
To normalize your recording:
- Press Ctrl+A to select the entire waveform.
- Choose Normalize from the Effect menu.
- Click OK in the dialog box and your waveform will be normalized.
The number in the Normalize screen under “Normalize maximum amplitude to” indicates the maximum volume your sound will have. I always put it on 0.0 dB, which is the maximum. Older versions of Audacity always normalize to -3.0dB, which is slightly less loud but still good.
Commercial pop music producers use “compressors” and “limiters” to make their records sound as loud as possible. I advise against doing that on your piano recordings. One of the unique characteristics of the piano is its wide dynamic range, from very soft to very loud, and compressing the sound will destroy this (but normalizing won’t).
Ideally, your recording will not contain any “noise”. Noise is sound that is picked up from unshielded cables, outside influences, and unmatched impedances. This is why we try to record as loudly as possible: the better the signal (i.e. the “real” sound) is, the less noise we hear.
Audacity can help us to get rid of all the noise, but this only works if the noise is relatively small compared to the real signal. This procedure is not required, but it may help if your recording isn’t entirely clean.
Noise reduction works in two steps:
- Typically there will some silence at the beginning and/or end of your recording. This isn’t real silence, because it contains noise. Select as much of this “silence” as possible and choose Noise Removal from the Effect menu. Click Get Noise Profile.
- Press Ctrl+A to select your entire waveform. Again choose Noise Removal from the Effect menu. This time click OK and your waveform will be processed.
IMPORTANT: If you use noise reduction, do this before normalizing.
If there is a lot of noise in the recording compared to the real signal, then noise reduction will produce averse effects. Not only will it filter out the noise, it will also filter out some of the good stuff and make your recording worse. Use with caution.
Two other effects that you can apply to your recording are “equalization” and “reverb”. Audacity offers many options here, but I advise you to use them sparingly and with taste. Personally, I use the reverb function on my digital piano and leave it at that.
The final step is saving your recording to a file.
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