Documentation Wiki rss-feed

Ladder Filter


Name

Ladder Filter:

image:ladder_filter_expanded.png

1221 1127
ladder filter

Description

The Ladder Filter Agent is an EigenD built-in low pass filter plug-in modelled on the analogue ladder filter common in Moog synthesizers.

Ports

Audio input

  • Name:

1118 116
audio input

  • Input
  • Type: Number
  • Range: -1 to 1

The audio input is normally used to receive audio data from upstream Agents (often an Oscillator's audio output in this case).

Resonance input

  • Name:

1135 116
resonance input

  • Input, Set
  • Type: Number
  • Range: 0 to 1
  • Default: 0.8

The resonance input is a parameter set by the user which adjusts the amount of variable resonance (also known as 'Q') of the Ladder Filter.

Cutoff frequency input

  • Name:

4314 1128 116
cutoff frequency input

  • Input, Set
  • Type: Number
  • Range: 0 to 96000
  • Default: 5000

The cutoff frequency input is used to control the cutoff and tracking frequency of the Ladder Filter. It can be a value (in Hertz) set by the user, or can be used as a tracking frequency if the upstream Scaler's frequency output is connected to this input. The actual cutoff frequency can be calculated by adding the cutoff frequency to the value of the frequency offset (explained below).

Bend input

  • Name:

2317 116
bend input

  • Input, Set
  • Type: Number
  • Range: -1 to 1

The bend input is used for controlling the filter's cutoff frequency - an upstream EigenD controller (such as the Scaler's yaw output) is often connected to this input. Adjusting the value of the bend input will modulate the cutoff frequency within the specified 'frequency range'.

Frequency range

  • Name:

1128 3121
frequency range

  • Input, Set
  • Type: Number
  • Range: 0 to 72
  • Default: 24

The frequency range is a parameter used to define the range (in semitones) over which the 'bend input' will modulate the value of the cutoff frequency.

Frequency offset

  • Name:

1128 1436
frequency offset

  • Input, Set
  • Type: Number
  • Range: -72 to 72
  • Default: 24

The frequency offset is an offset (in semitones) applied to the value of the 'cutoff frequency input'. This enables the value of the cutoff frequency input to be used as a tracking frequency if the Scaler's frequency output is connected to it.

Temperature

  • Name:

1222
temperature

  • Input, Set
  • Type: Number
  • Range: 1 to 100
  • Default: 50

Temperature is a parameter which controls the non-linearity of the filter (it is normally a value set by the user).

Low pass output

  • Name:

4313 1175 125
low pass output

  • Output
  • Type: Number
  • Range: -1 to 1

The low pass output is normally used to send the output of the Ladder Filter to downstream Agents (often a Gain Agent's audio input in this case).

Nouns

None

Verbs

None

Examples

Before using the Belcanto examples below, make sure you have the desired Ladder Filter in the conversation using

1221 1127 ? 1131
ladder filter X listen

where X is the number of the desired ladder filter.

Setting the value of the resonance input

To set the resonance input, use

1135 116 23 ? 67
resonance input to X set

where X is the value of the desired resonance.

Setting the value of the cutoff frequency input

To set the cutoff frequency, use

4314 1128 116 23 ? 67
cutoff frequency input to X set

where X is the value of the desired cutoff frequency.

Setting the frequency range

To set the frequency range, use

1128 3121 23 ? 67
frequency range to X set

where X is the value of the desired frequency range.

Setting the frequency offset

To set the frequency offset, use

1128 1436 23 ? 67
frequency offset to X set

where X is the value of the desired frequency offset.

Setting the temperature value

To set the value of the temperature parameter, use

1222 23 ? 67
temperature to X set

See also