User`s manual

90
4.4.13: Hi-Res Graphic Filter
Application:
In some applications, it may be necessary to precisely reshape the spectrum of input audio
prior to passing it through successive filter stages. For example, if the audio is from a
microphone which has an unusual frequency response curve (for example, a microphone
acoustically modified as a result of concealment), a compensation filter that reshapes the
audio to a normal spectral shape might be desirable.
The Hi-Res Graphic Filter is essentially a 460-band graphic equalizer; however, instead of
having 460 separate slider controls, it allows the user to precisely draw the desired filter
shape on the computer screen, using the mouse, with as much or as little detail as desired.
Once the filter shape has been drawn, a linear-phase digital filter is constructed in the PC
and transferred to the external processor.
The Edit feature allows the user to make readjustments to the filter shape, while the
Normalize button allows the user to shift the entire filter curve up until the highest point is at
0dB.
A Store and Recall capability is also provided to allow the user to store commonly-used filter
shapes to disk memories so that they can be recalled later.
Figure 4-48 Hi-Res Graphic Filter Window