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Chapter 14 Ultrabeat 348
Ultrabeat noise generator
Ultrabeat’s exible noise generator enables you to create a wide range of percussive sounds and
sound elements. The noise generator has its own lter, which functions independently of the
main Ultrabeat lter, although the noise generator lter can also be used on the overall sound.
Technically, a noise signal contains all tonal frequencies, at a roughly equal volume level. As
all frequencies in the spectrum are audible, it makes it dicult for human beings to hear any
tonality (pitch) in a noise signal. Despite this, or as a direct result of it, noise is an indispensable
ingredient when creating drum sounds.
Filter Type buttons
On/off button
Cutoff knob and “mod”
and “via” menus
Volume knob
Dirt knob and “mod” and
“via” menus
Res(onance) knob
Mod and “via” menus
(for volume)
Noise generator parameters
•
On/O button: Turns the noise generator on or o. When programming a drum sound, you
can turn the individual sound sources on or o. You can also listen to, or remove, individual
components of the sound separately in this way.
•
Filter Type buttons: Switch the noise generator’s integrated lter between lowpass, highpass,
and bandpass lter types.
•
LP (lowpass): This lter type allows frequencies that fall below the cuto frequency to pass.
The lter slope is xed at 12 dB/octave.
•
HP (highpass): This lter type allows frequencies above the cuto frequency to pass. The lter
slope is xed at 12 dB/octave.
•
BP (bandpass): The frequency band directly surrounding the center frequency (determined
with the Cuto knob) is allowed to pass. All other frequencies are cut. The Resonance
parameter controls the width of the frequency band. The bandpass lter is a two-pole lter
with a slope of 6 dB/octave on each side of the center frequency of the band.
•
byp (bypass): Disables the integrated lter.
•
Cut(o) and Res(onance) knobs: Rotate to set the cuto/center frequency and resonance/
bandwidth behavior of the integrated lter.
•
The Cut knob denes the point in the frequency spectrum where the signal is boosted or
cut. Depending on the selected lter type, you can make a sound darker (LP), thinner (HP), or
more nasal (BP) by adjusting the Cut value. Cuto can be modulated by sources in the mod
and via pop-up menus.
•
Increasing resonance boosts frequencies that surround the cuto frequency. Values range
from 0 (no increase) to self-oscillation of the lter at high resonance values. Self-oscillation
is typical of analog lter circuits. It occurs when the lter feeds back into itself and begins to
oscillate at its natural frequency when high resonance values are used.