Yamaha MO8 Owner's Manual - Page 133

Basic Structure ● Filter [VOICE] ➞ Voice selection ➞ [EDIT] ➞ Element selection/ Drum Key selection ➞ [F3] FILTER This unit modifies the tone of the sound output from Pitch by cutting the output of a specific frequency portion of the sound. Cutoff Frequency and Resonance Here's how filters work. In the example below (a low pass filter), a portion of the signal lower than a given frequency is allowed to pass, and signals above that frequency are cut. This frequency is referred to as the Cutoff frequency. You can produce a relatively bright or darker sound by setting the cutoff. Resonance is a parameter that boosts the level of the signal in the area of the cutoff frequency. By emphasizing the overtones in this area, this can produce a distinctive "peaky" tone, making the sound brighter and harder. Level Cutoff frequency Internal Structure (System Overview) • Band Pass Filter This passes only those a band of signals around the Cutoff frequency. The width of this band can be varied. Level Range passed Cutoff range Center frequency Frequency • Band Elimination Filter This attenuates a band of signals around the Cutoff frequency, but passes everything else. Level Cutoff range Level These frequencies are "passed" by the filter. Resonance Frequency (pitch) Frequency (pitch) Cutoff frequency About the main Filter types The Low Pass Filter is shown in the illustration above- however, this synthesizer features four other Filter types as shown below. • Low Pass Filter (above) This passes only those signals below the Cutoff frequency. You can then use the Reso (Resonance) parameter to add further character to the sound. • High Pass Filter This passes only those signals above the Cutoff frequency. You can then use the Reso (Resonance) parameter to add further character to the sound. Level Resonance These frequencies are "passed" by the filter. Center frequency Range passed Frequency FEG (Filter Envelope Generator) Using the FEG, you can control the transition in tone from the moment the sound starts to the moment the sound stops. You can create the FEG by setting parameters as illustrated below. When you press a note on the keyboard, the cutoff frequency will change according to these envelope settings. This is useful for creating automatic wah or filter sweep effects, for example. Furthermore, different FEG parameters can be set for each Element or each Key. Cutoff Frequency Attack Level Hold Level Decay1 Level Sustain Level (Decay2 Level) 0 Hold Time Attack Decay1 Decay2 Time Time Time Release Level Release Time Time Pressing the key (Key on) Releasing the key (Key off) Cutoff frequency Owner's Manual 133