13
A
DVANCED MODE
Click on the
Advanced
button to switch an EQ band to Advanced mode.
In Advanced mode, each filter band is specified by the
biquad coefficients
of
that filter. This is a set of five numbers that directly specifies the numerical
computations performed by the filter. The coefficients must be generated by
a filter design program (see next page).
Biquad coefficients can be entered or pasted directly into the user interface:
The format of the text entry field is as follows:
biquad1,
b0=0.998191200483864,
b1=-1.9950521500467384,
b2=0.996920046761057,
a1=1.9950521500467384,
a2=-0.9951112472449212
After entering or pasting in the coefficients for a band, press the
Process
button.
Biquads can also imported from a file. The file can contain from one to ten
biquads in the format given above. Note that commas must separate each
biquad, and the last line of the file should not end with a comma. Click on the
Import
button to import a biquad file.
•
Biquads are always imported starting from filter band EQ1, regardless of
the numbering in the biquad file.
•
The same number of biquads as in the file are imported. However, some
programs (e.g. REW) generate a file with ten biquads even if only some
have coefficients.
