23
OB-6 Operation Manual
Filter Envelope
Attack:
Sets the attack time of the envelope. The higher the setting, the
slower the attack time and the longer it takes for the filter to open from
the level set with the filter
frequency
knob to the level set by the filter
envelope amount. Percussive sounds typically have sharp (short) attacks.
Decay:
Sets the decay time of the envelope. After a sound reaches the
filter frequency set at its attack stage,
decay
controls how quickly the
filter then transitions to the cutoff frequency set with the
sustain
knob.
The higher the setting, the longer the decay. Percussive sounds, such as
synth bass, typically have shorter decays (and a generous amount of low-
pass filter resonance).
Sustain:
Sets the filter cutoff frequency for the sustained portion of the
sound. The sound will stay at this filter frequency for as long as a note is
held on the keyboard.
Release:
Sets the release time of the envelope. This controls how
quickly the filter closes after a note is released.
Velocity:
on, off
—When enabled, allows key velocity to influence filter
frequency. If the
amount
is set to a positive value in low-pass filter
mode, the harder you play, the more the filter will open and the brighter
the sound will be. Conversely, if the
amount
is set to a negative value,
the harder you play, the more the filter will close and the less bright the
sound will be. This control makes for more touch-sensitive sounds
Amount:
Sets the amount of modulation from the filter envelope to the
filter. Higher amounts more dramatically affect the cutoff frequency. This
control is bipolar. Positive settings produce standard behavior. Negative
settings invert the envelope.
The description of envelope behavior above is true when the
amount
parameter
is set to a positive value. But since this control is actually bi-polar, it is possible to set
a negative amount of modulation. In this case, the envelopes are inverted and their
behavior changes. The best way to get a feel for the difference is to experiment with
both positive and negative settings of the
envelope
amount
parameter.
The cutoff frequency setting may limit the effect of the envelope on the filter. For
example, in low-pass filter mode , if
frequency
is at its highest setting, a positive enve-
lope amount will have no effect on the filter since the filter is already completely open.
Summary of Contents for ob-6
Page 1: ...Operation Manual...
Page 2: ......
Page 10: ......
Page 94: ...84 Appendix C MIDI Implementation Dave Smith Instruments...
Page 95: ......