Dynamic range compression: Difference between revisions

Revision as of 01:28, 5 June 2005

Revision as of 04:27, 15 June 2005

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== Common uses ==

Compression is often used to make music sound louder without increasing its peak amplitude. Instead, it boosts the perceived loudness by increasing the [[root mean square]] volume. In other words, the peak of a sound wave of, say, a drum hit may be at roughly the same amplitude, but the sound is louder relative to the peak as the sound decays than it would be without compression. This reduction of the dynamics makes the drum sound louder even though it peaks at the same place. It is common to compress [[rock and roll|rock music]] or [[pop music]] heavily to make it sound louder without introducing undesirable distortion from higher amplitudes. This idea is also used in [[broadcasting]] to boost the perceived volume of the sound track, since broadcasters have limits on the instantaneous peak volume.

Compression is commonly used in [[television commercial|TV advertising]] to boost the perceived volume of the sound track. [[Television|TV]] broadcasters have limits on the instantaneous peak volume of the audio track in a broadcast rather than its [[root mean square]] volume over the entire 30 second commercial segment. By applying compression followed by gain compensation the overall volume of the track is increased without increasing its peak volume and the sound is perceived as louder.

Compression can also be used on instrument sounds to give certain effects unrelated to boosting loudness. For instance, drum and cymbal sounds tend to decay quickly, but a compressor can make the sound appear to have more sustain.

== Underlying electronics ==