UAD Powered Plug-Ins Manual v5.2 - Just Music

Low Cut / High Cut Filters
The Low Cut and High Cut filters are offered in addition
to the five parametric/shelf bands. A wide
range of filter types is provided to facilitate tonal
creativity. Many filters that are available are represented.
Three controls are offered: Cut Type, Enable, and
Frequency. Each control is detailed below.
Cut Type Menu
The Cut Type menu determines the sound of the low
and high cut filters. To view the Cut Type menu, click
and hold the green cut type button.
Four types of responses are provided: Coincident
Pole, Bessel, Butterworth, and Elliptic. The numbers
represent the filter order, i.e. Bessel 4 is a fourth-order
filter. Each offers a different sound. To select a
new cut response, drag to the desired response and
release.
The responses are more gentle on filters with lower
numbers, and get steeper and more aggressive as
the numbers increase. The coincident-pole filters are
first-order filters cascaded in series and offer gentle
slopes. Bessel filters are popular because of their
smooth phase characteristic with decent rejection. Butterworth filters offer
even stronger rejection. The Elliptic setting is about as “brick wall” as you can
get. Generally speaking, more phase shifting occurs as the response gets
steeper.
Note: UAD DSP usage does increase some as the filters get stronger.
Cut Enable
Button
Cut Frequency
Knob
This button activates the cut filters. The filters are enabled when the “In” button
is green. UAD DSP usage is slightly reduced when the cut filters are disabled.
This knob determines the cutoff frequency for the Cut filters. The available
range is from 20Hz-5kHz for the low cut filter, and 20Hz-20kHz for the high
cut filter.
UAD Powered Plug-Ins Manual - 205 - Chapter 22: Cambridge EQ