Difference between revisions of "Compression"
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Because compression makes the loudest transients of audio signals quieter, it can have the effect of making the overall audio quieter and as such some 'make up gain' might be required. This quite simply turns up the output of a compressor. There are various better guides available online. if you wish to learn more. | Because compression makes the loudest transients of audio signals quieter, it can have the effect of making the overall audio quieter and as such some 'make up gain' might be required. This quite simply turns up the output of a compressor. There are various better guides available online. if you wish to learn more. | ||
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Latest revision as of 14:18, 29 June 2019
Not to be confused with data compression common in .mp3s, compression as used by Engineering refers to the compression (or reduction) of the dynamic range of a signal. Most basic compressors have a threshold, ratio and make up gain control.
Threshold
The threshold is where, above a certain level of loudness, such as -30dB (where 0dB is maximum relative loudness) the compressor begins reducing the dynamic range or maximum peak values of the audio signal.
Ratio
The ratio is how hard a compressor works to reduce dynamic range above the threshold. With a threshold of 1:1, the Compressor does not do anything to the audio signal. If the threshold of the compressor is -30dB, and the ratio is 4:1, then the input signal will have to increase 4dB in order for the output signal to increase 1dB. For example, an input volume of -30dB will produce an output volume of -30dB, an input volume of -26dB would produce an output volume of -29dB, and an input volume of -22dB would produce an output volume of -28dB.
Make Up Gain
Because compression makes the loudest transients of audio signals quieter, it can have the effect of making the overall audio quieter and as such some 'make up gain' might be required. This quite simply turns up the output of a compressor. There are various better guides available online. if you wish to learn more.
Take me back to Dynamics