miniDSP Ltd, Hong Kong /
/ Features and specifications subject to change without prior notice
39
A single biquad like this can perform a great many functions, including all of the functions of a single parametric
EQ filter, one 6 or 12 dB/octave high pass or low pass filter, and more. Biquads are combined in series
(cascaded) to create more complex filters. The function that each biquad performs is determined by just five
numbers:
a1
,
a2
,
b0
,
b1
, and
b2
. These numbers are called the
coefficients
.
8.4.2
Using custom biquad programming
Each crossover block and PEQ filter has a selector that switches it to advanced mode:
In advanced mode, the biquad coefficients can be pasted directly into the user interface. These coefficients must
be calculated using a design program
–
Parametric EQ advanced mode
In the parametric EQ blocks, advanced mode allows each individual filter to be specified by its biquad
coefficients. After pasting in the coefficients, click on the
Process
button.
Parametric EQ file import (REW integration)
Multiple biquads in the parametric EQ block can be set at once by importing a coefficient file. This file can
be generated by Room EQ Wizard (REW) or by other programs. The design program must be set for a
48 kHz
sample rate. The number of filters is limited to a maximum of ten.
This example illustrates the correct file format:
biquad1,
b0=0.998191200483864,
b1=-1.9950521500467384,
b2=0.996920046761057,
a1=1.9950521500467384,
a2=-0.9951112472449212,
biquad2,
b0=0.999640139948623,
b1=-1.9981670485581222,
...
biquad3,
...
biquad4,
...
biquad10,
b0=1.0010192374642126,
b1=-1.9950555192569264,
b2=0.9940580112181501,
a1=1.995060938714333,
a2=-0.9950718292249559
