Alesis QuadraSynth Plus Car Speaker User Manual


 
Editing Programs: Chapter 6
QuadraSynth Plus Piano Reference Manual 85
Filter
Filter (Page 1)
Frequency (00 to 99)
This sets the filter's initial cutoff frequency. Lower values give a
duller sound since this removes more harmonics; higher values
let through more harmonics, which gives a brighter sound.
Tip: Signals with complex harmonic structures are most affected
by the filter. Examples: A sine wave has virtually no harmonics so
you will not hear any significant changes as long as the filter
cutoff is higher than the note pitch. If the filter cutoff is lower
than the note pitch, you will either not hear the note, or it will be
very soft. A harmonically-rich sample (such as brass or white
noise) will be greatly affected by the filter.
If the Filter Frequency is set to maximum, in most cases all other
variables in the Filter function will have no effect. Most other
filter functions raise the filter frequency, and it can't be greater
than 99. So if you want to use filter effects, proper setting of this
initial cutoff frequency is crucial. This is the "baseline" from
which all other filter parameters will raise or lower (open or
close) the filter.
If the Filter Frequency is set to 00, and no other parameters are
set to raise it dynamically, no sound will pass through the filter
at all--there will be silence. If the Amp settings are wide open
and you can't hear anything, check the Filter Frequency setting.
Since the waveforms in ROM are recorded at the brightest
possible setting, in many cases dynamic filtering is crucial to
making a program sound natural.
Keyboard Track (On or Off)
When off, the filter cutoff remains constant across the keyboard.
Higher notes will be more affected than lower notes, since the
filter cutoff is comparatively lower for higher notes than lower
ones.
When on, the filter frequency tracks the keyboard pitch.
Therefore, if using the filter creates a particular harmonic
structure when you play one key, playing a different key will
shift the filter frequency to maintain the same harmonic
structure.
Velocity (-99 to +99)
At +00, velocity has no effect on the filter cutoff. With positive
values, playing harder increases the filter cutoff. More positive
values drive the cutoff frequency higher for a given amount of
velocity. More negative values drive the cutoff frequency lower
for a given amount of velocity.
Tip: Many acoustic instruments, such as acoustic guitars, sound
brighter when you play them more forcefully. Adding a little