# Equalizer

PulseEffects uses the parametric equalizer from Linux Studio Plugins. You can choose between 1 and 30 bands. You also can change the center frequency and the width of each band as needed. There are a few presets but at this moment all of them have only 10 bands. Presets with other number of bands may be added in the future.

# Main Menu

## Режим

IIR - Infinite Impulse Response filters, nonlinear minimal phase. In most cases does not add noticeable latency to output signal.

FIR - Finite Impulse Response filters with linear phase, finite approximation of equalizer's impulse response. Adds noticeable latency to output signal.

FFT - Fast Fourier Transform approximation of the frequency chart, linear phase. Adds noticeable latency to output signal.

## Bands

The number of equalizer bands.

## Split Channels

When this option is enabled it is possible to apply different equalizations to the left and the right channel.

## Flat Response

This function sets each band gain to 0.

## Подсчитать частоты

This function can be used to calculate the center frequencies and bandwidth of a graphic equalizer with the current number of selected bands. Useful when the user does not want the default number of 30 bands but has no idea about which frequencies and bandwidth he/she should choose.

## Reset Equalizer

Reset the equalizer to its default settings.

# Band Menu

## Type

Off - Filter is not working (turned off).

Bell - Bell filter with smooth peak/recess.

High-pass - High-pass filter with rejection of low frequencies.

High-shelf - Shelving filter with adjustment of high frequency range.

Low-pass - Low-pass filter with rejection of high frequencies.

Low-shelf - Shelving filter with adjustment of low frequencies.

Notch - Notch filter with full rejection of selected frequency.

Resonance - Resonance filter wih sharp peak/recess.

## Режим

RLC - Very smooth filters based on similar cascades of RLC contours.

BWC - Butterworth-Chebyshev-type-1 based filters. Does not affect Resonance and Notch filters.

LRX - Linkwitz-Riley based filters. Does not affect Resonance and Notch filters.

APO - Digital biquad filters derived from canonic analog biquad prototypes digitalized through Bilinear transform. These are textbook filters which are implemented as in the Equalizer APO software.

(BT) - Bilinear Z-transform is used for pole/zero mapping.

(MT) - Matched Z-transform is used for pole/zero mapping.

(DR) - Direct design is used to serve the digital filter coefficients directly in the digital domain without performing transforms.

## Slope

The slope of the filter characteristics.

## Solo

Makes this band the only one active.

## Mute

Mutes the band.

## Frequency

Band center frequency.

## Width

Bandwidth. Calculated as `width = frequency / quality`.

## Quality

Quality factor.

# Отклики

http://lsp-plug.in/?page=manuals&section=para_equalizer_x32_lr

https://en.wikipedia.org/wiki/Equalization_(audio)

https://en.wikipedia.org/wiki/Q_factor

https://howtoeq.wordpress.com/2010/10/07/q-factor-and-bandwidth-in-eq-what-it-all-means/