Shelf Filter

From Audacity Development Manual
Jump to: navigation, search
Shelf Filter a shelf filter curve is flat at both ends rather than flat only at the frequencies being passed.
  • Use these filters when you do not want to reduce the lowest bass or highest treble frequencies as much as you would with a standard high pass or low pass filter.
  • Or if you actually want to boost either the low or high frequencies respectively.
Advice Note carefully that when you apply an effect to a time-stretched clip the changed speed of the clip will be automatically rendered.
  • If you apply an effect to a selection within a time-stretched clip then Audacity will split the original clip so that the selection can be rendered as part of applying the effect.
Alert If you apply this effect with an envelope present then there is a bug whereby the envelope is removed and the audio reverts to its full amplitude state prior to the effect being applied.
Accessed by: Effect > EQ and Filters > Shelf Filter
Shelf Filter 3-5-0.png

Filter type

This shelf filter has a constant filter slope of 6dB per octave.

Two options are available:

  • Low Shelf: to boost or cut low frequencies.
  • High Shelf: to boost or cut high frequencies.

Frequency (Hz)

The "filter frequency" is the mid-point of the filter slope. This is also known as the center frequency, or half gain frequency.

Low shelf filter with 6dB boost and 250 Hz center frequency.

Amount (dB)

The maximum amount of boost or reduction that will be applied. Negative amounts represent a reduction.


|< Index of Effects, Generators and Analyzers

|< Effect Menu