Parametric EQ |
The Parametric Equalizer is a set of four frequency-selective filters that allow for very precise changes in the frequency content of a sound signal:
A high-frequency shelf filter attenuates frequencies above a specified cutoff frequency. This filter is useful for removing high-frequency noise such as wind, tape hiss, or computer noise.
A low-frequency shelf filter attenuates frequencies below a specified cutoff frequency. This filter is useful for removing low-frequency rumbles such as wind, electrical hum, or traffic noise.
A band-pass filter attenuates or boosts frequencies outside of a specified range of frequencies. This filter is useful for removing hiss and low-frequency rumble simultaneously or boosting a specific frequency range.
A band-reject (or notch filter) attenuates frequencies within a specified range of frequencies. This filter is useful for removing to remove narrow-bandwidth noise such as amplifier/microphone feedback or 60 Hz electrical hum.
Open the Sonic Foundry Parametric EQ dialog.
Choose a preset from the Name drop-down list, or choose a filter from the Filter style drop-down list.
Adjust the filter frequency:
If you're using the High-frequency shelf filter, drag the Cutoff frequency slider to set the frequency above which the filter will be applied. The Transition width slider sets the slope of the filter.
If you're using the Low-frequency shelf filter, drag the Cutoff frequency slider to set the frequency below which the filter will be applied. The Transition width slider sets the slope of the filter.
If you're using the Band-pass or Band-notch/boost filter, drag the Center frequency slider to set the frequency at which the filter will be applied. The Band width slider controls the range of frequencies affected by the filter.
Drag the Amount fader to set the gain applied to the specified frequency band. This gain may be positive or negative.
Drag the Output gain fader if you want to apply a gain after processing.
Choose a setting from the Accuracy drop-down list to determine a balance between filter precision and processing speed.
Low
precision is not recommended for performing very sharp filtering,
when filtering very low frequencies, or when using a high sample rate.