Adobe 22011292 User Guide - Page 170

156 CHAPTER 8 Effects Menu - Edit View Low Shelf Cutoff High and low pass filters cut the extreme high- or low-end of the audio spectrum. The low pass (so named because it allows the low frequencies to pass, while reducing the highs) is often used to reduce hiss, amplifier noise, and the like. To fine-tune the range of frequencies being boosted or cut, adjust the Low Shelf Cutoff slider located directly below the graph, or enter a specific frequency in the box to the right of the slider. High Shelf The slider directly to the right of the graph determines the High Shelf amplitude in dB. To increase or decrease the highs (treble) at any time, just adjust the slider, or enter a dB level in the box at the bottom of the slider. High Shelf Cutoff High and low pass filters cut the extreme high- or low-end of the audio spectrum. The high pass (so named because it allows the high frequencies to pass, while reducing the lows) is often used to reduce low-end rumble, hum, or other unwanted low-frequency sounds. To fine-tune the range of frequencies being boosted or cut, adjust the High Shelf Cutoff slider located directly below the graph, or enter a specific frequency in the box to the right of the slider. Intermediate Bands You can place up to five intermediate bands into the EQ circuit. This gives you very fine control over the shape of the equalization curve. Check the box next to a slider to activate the band and its corresponding volume slider. The vertical sliders in the upper right of the Parametric Equalizer window control the amount of boost or cut. You can also enter boost/cut amount (dB) in the entry box below each slider. The horizontal sliders located below the Cutoff sliders control the center frequency at which the boost or cut will occur. A frequency may also be entered in the box to the right of the slider. Width The Q or Width value (depending on the Constant Q/Width setting below) controls the width of the affected frequency band. With lower Q values (or greater Width values), a larger range of frequencies will be affected. If a Q value is very high (above 100), only a very narrow band will be affected, which is ideal for notch filters where only a particular frequency needs to be removed, like a 60-cycle hum. You should be aware that whenever a very narrow band is boosted, it will tend to "ring" or resonate at the audio at that frequency. Q values of 1 to 10 are used most often for general equalization. Constant Width/Constant Q This parameter describes a frequency band's width. This can be a Q value (which is a ratio of width to center frequency) or an absolute width value in Hz. Constant Q is the most common setting, but you may want to use Constant Width if, for example, you want the length of ringing to be a constant, no matter which frequency is being boosted. Master Gain After the EQ settings have been adjusted, the overall volume level might be too loud or too soft. This can be compensated for by entering an overall master gain (measured in dB) to be applied to the resultant audio. Presets Adobe Audition comes with several Parametric Equalizer presets. More information on presets can be found in the "Looking at the Work Area" chapter. Preview Press the Preview button to audition the current Parametric Equalizer setting before you apply it to the waveform. The selection is looped until you press the Stop button. Since Adobe Audition's Previews are dynamic, this gives you the opportunity to make and hear processing adjustments as the selection is continuously played.