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Chapter 14. Effects -- Close Up > COMP-01 Auto Make Up Gain Compressor - Pg. 316

The carrier is ideally an audio source that is constantly generating sound. A good example of this is a string pad playing from the Subtractor in a sequence that is looped continuously. The modulator is typically an audio source such as a spoken voice or vocal track. Another typically used modulator is a drum loop for creating rhythmically enhanced sounds. Once you have these two elements, they are then routed to their appropriate vocoder inputs. The modulator is divided into a set number of bands (4, 8, 16, 32, or 512) by using band pass filters. These separate bands are then sent to an envelope follower (a device that continuously monitors and analyzes the signal levels). Meanwhile, the carrier is processed with the same number of bands as the modulator. The same frequency ranges used in the modulator's band pass filters are also applied to the carrier. By doing this, the carrier will have the same frequency characteristics as the modulator. This means that if the modulator gets louder or more dynamic in shape, the carrier will follow and emulate this as well. THE VOCODER IN ACTION If you want to hear good audio examples of vocoding, listen to just about any CD by Laurie Anderson ("O'Superman"), Daft Punk ("Around the World"), Air ("Remember"), or Zapp and Roger ("More Bounce to the Ounce"). Let's have a look at the basic parameters of the BV512. Level Meters--These meters display the signal level of the carrier and the modulator. Band Switch--This switches between the number of filter bands (4, 8, 16, 32, or 512). Equalizer/Vocoder Switch--This switches the BV512 between vocoder mode and equalizer mode. Note that when using the BV512 in equalizer mode, the modulator input is not used. Modulation Level Display--This displays the overall spectrum of the modulation signal. Frequency Band Level Adjust--This display is used to adjust the levels of the individual filter bands. When using this section in vocoder mode, each band adjusts the sound and shape of the vocoder. When using this section in equalizer mode, each band adjusts the amplitude of the individual frequencies in the EQ curve. After making adjustments to the individual bands, you can use the Reset Band Levels option from the Edit pull-down menu. Hold Button--When activated, this button freezes the current filter settings. The modulator signal will no longer affect the carrier in this mode. Clicking it again will release the filter settings. Attack--This parameter affects the overall attack of the frequency bands. Increasing the attack amount can create some very cool pad sounds. Note that when the BV512 is in equalizer mode, this parameter is not available.