Equalization (audio)#Shelving filter

A shelving ( also inaccurate Kuhschwanzregler, in English shelving filter) is an audio filters or tone control for analog or digital sound processing of the ends of the frequency response.

Its name derives from the appearance of the frequency response characteristic which has the shape of a Kuhschwanzes. It also resembles the schematic profile of the shelf, which is derived the English name.

The effect and operation

The effect of the filter starts slowly at the operating frequency and decreases until the end of the frequency range to be dynamic.

Shelving is used for modifying the amplitude of the height or the depth range. The desired level is reduced by a certain frequency on shelving or whippy (damped) or increased ( amplified). In the case of reinforcing the frequency response looks similar to the profile of a continental shelf: the level is gradually increased and finally remains at the higher level are.

This " base ", which is formed by a second time constant, the response of a shelving filter differs from that of a high - or low-pass filter. In contrast to this, a shelving filter for frequency reduction and elevation will be used.

The characteristics of a shelving filter is also different from that of a bell-shaped frequency change with the help of equalizers.

The functioning of the adjacent circuit explained simplistic way: the left branch of the circuit to adjust the depth stake, the potentiometer is virtually short -circuited by the capacitor connected in parallel for high frequencies and thus ineffective for this. In contrast, low frequencies are blocked by two capacitors in parallel arranged right circuit portion, whereby the potentiometer acts only as adjusters for high -frequency components. The output signals of the two individual filters are combined via coupling resistors to form a single output signal.