User`s manual

Analyzer Block: Used to control the spectrum analyzer which acquires the original audio

power spectrum; this spectrum is displayed and continuously updated

in the Filter Display area as a yellow trace. Analyzer controls include:

• Clear button which is used to zero the averager memory and cause

the averaged spectrum to be recalculated anew.

• Run button which allows the user to start (GREEN LED

indication) or stop (LED unlit) update of the averaged spectrum.

• Number of Averages setting which allows the user to specify the

degree of smoothing of the original audio power spectrum. For

minimum smoothing, set to 1; for maximum smoothing, set to 128.

A long-term power spectrum (64 to 128 averages) is best for

setting up the filter.

• Gain control which allows the user to apply a digital gain of up to

40dB to the analyzer input, allowing low-level spectrum

components to be displayed; however, if excessive gain is applied,

the analyzer input will overload, causing the Gain label to change

to OVL (analyzer overload) and the captions at the bottom of the

Filter Display area to change color to red.

Filter Operation Block:

Specifies whether SIF is to be used to Equalize Voice or Attack

Noise. When Equalize Voice is selected, the SIF control window

appears as shown in Figure 4-38. When Attack Noise is selected, the

SIF Control Window appears as shown in Figure 4-39.

Equalize Voice operation is used to reshape the original input voice

audio to a more natural-sounding spectral shape over a specified

frequency range. All audio outside this frequency range is attenuated by

40dB.

Attack Noise operation is used to attack large-magnitude narrow-band

noises (such as motor noises) over a specified frequency range. Audio

outside this frequency range remains unaffected (0dB attenuation).