FIR Custom Filter Component

Q-SYS provides the capability of loading your filter design results into the FIR (Finite Impulse Response) Custom Filter, giving you explicit control over the phase and magnitude response of the Custom FIR filter.

You set the size of the FIR filter, in the component properties, by specifying the number of coefficients. If the FIR Filter component has more coefficients defined than what is contained in the loaded file, Q-SYS assigns zeros to missing coefficients. If there are more coefficients in the file than defined in the design, Q-SYS discards the extra coefficients.

Coefficient File

Typically, a FIR filter is designed using filter design software that computes the coefficients. After you design the filter, you must export the coefficients to a .csv (comma separated value) or .wav file. This file is then loaded into the Q-SYS FIR Custom Filter at runtime. The .csv file containing the coefficients is a row of values, separated by commas, representing time from left to right.

Controls

Control	Function	Default/Range
Response Graph	The scales for the Response Graph vary depending on the measurement method you select, see below. The vertical line of the crosshair cursor provides a readout of its position on the X axis scale. The vertical movement of the horizontal crosshair follows the magnitude or amplitude of the signal.	N/A
Magnitude	Measures the magnitude of the input signal over the audio frequency range. Represented by the blue line.	X Axis = 20Hz to 20kHz Y Axis Left = -20dB to 20 dB
Magnitude/Phase	Same as the Magnitude selection but with the addition of a phase line.	X Axis = 20Hz to 20kHz Y Axis Left, Gain = -20dB to 20 dB Y Axis Right, Phase = -180° to 180°
Impulse	Measures amplitude (Y axis) vs. time in milliseconds (X axis) of the energy pulse. If you enter 4 (the minimum), the time displayed on the X axis of the Response Graph is from 0.00 ms to 0.06 ms. If you enter 1024 (the maximum), the time displayed across the X axis is 0.00 ms to 21.3 ms.	X Axis = 0.0ms to 5.3 ms Y Axis Left = -1.0 to 1.0
Load Coefficients	Opens a standard Windows "Open" dialog box where you can navigate to, and open either a .csv or .wav file containing the coefficients defining the filter.	.csv or .wav file

Control

Function

Default/Range

Response Graph

The scales for the Response Graph vary depending on the measurement method you select, see below.

The vertical line of the crosshair cursor provides a readout of its position on the X axis scale.

The vertical movement of the horizontal crosshair follows the magnitude or amplitude of the signal.

N/A

Magnitude

Measures the magnitude of the input signal over the audio frequency range. Represented by the blue line.

X Axis = 20Hz to 20kHz

Y Axis Left = -20dB to 20 dB

Magnitude/Phase

Same as the Magnitude selection but with the addition of a phase line.

X Axis = 20Hz to 20kHz

Y Axis Left, Gain = -20dB to 20 dB

Y Axis Right, Phase = -180° to 180°

Impulse

Measures amplitude (Y axis) vs. time in milliseconds (X axis) of the energy pulse.

If you enter 4 (the minimum), the time displayed on the X axis of the Response Graph is from 0.00 ms to 0.06 ms. If you enter 1024 (the maximum), the time displayed across the X axis is 0.00 ms to 21.3 ms.

X Axis = 0.0ms to 5.3 ms

Y Axis Left = -1.0 to 1.0

Load Coefficients

Opens a standard Windows "Open" dialog box where you can navigate to, and open either a .csv or .wav file containing the coefficients defining the filter.

.csv or .wav file

Properties

Property	Function	Choices
Coefficient Count	Determines the number of coefficients for the filter. The quantity defined here must match the number of coefficients contained in the .wav or .csv file loaded at runtime.	4 to 4096
Type	Sets the type of Channel input and output.	Mono Stereo Multi-channel
Count	When Multi-channel Type is selected, you can select from 2 to 256 channels.	2 to 256

Property

Function

Choices

Coefficient Count

Determines the number of coefficients for the filter. The quantity defined here must match the number of coefficients contained in the .wav or .csv file loaded at runtime.

4 to 4096

Type

Sets the type of Channel input and output.

Mono

Stereo

Multi-channel

Count

When Multi-channel Type is selected, you can select from 2 to 256 channels.

2 to 256

Control Pins

There are no Control Pins available for the FIR Custom Filter.

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