# FIR Custom Filter

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.

You can load a custom FIR coefficients file at runtime. Typically, a FIR filter is designed using filter design software that computes the coefficients. After you design the filter, you export the coefficients to a .csv (comma separated value) or .wav file. This file is then loaded at runtime by clicking Load Coefficients - see Controls. The file containing the coefficients is a row of values, separated by commas, representing time from left to right.

**Note: **Ensure that the Coefficient Count equals the number of coefficients (FIR taps) in your FIR coefficients file. See FIR Custom Filter.

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 impulse response. |
X Axis =depends on Coefficient Count 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 |

Property |
Function |
Choices |
---|---|---|

Coefficient Count |
Determines the number of coefficients for the FIR filter. The quantity defined here must match the number of coefficients contained in the .wav or .csv file loaded at runtime. |
4 to 16,384 |

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 |

Pin Name |
Value |
String |
Position |
Pins Available |
---|---|---|---|---|

Master: Bypass |
0 1 |
no bypassed |
0 1 |
Input / Output |

JSON |
(text) |
Input / Output |