Operation Manual

NN-XT SAMPLER
179
The Filter Section
Filters can be used for shaping the character of the sound. The filter in NN-XT is a
multimode filter with six different filter types.
D To activate/deactivate the filter, click the On/Off button in the top right
corner.
When the filter is activated, the button is lit.
Filter mode
To select a filter mode, either click the Mode button in the bottom right corner or click
directly on the desired filter name so that it lights up:
D Notch
The notch filter is used for cutting off frequencies in a narrow frequency range
around the set cutoff frequency, while letting the frequencies below and above
through.
D HP 12
This is a highpass filter with a 12 dB/Octave roll-off slope. A highpass filter cuts off
low frequencies and lets high frequencies pass. That is, frequencies below the
cutoff frequency are cut off and frequencies above it pass through.
D BP 12
This is a bandpass filter with a 12 dB/Octave roll-off slope. A bandpass filter could
be viewed as the opposite of a notch filter. It cuts off both the high and the low fre-
quencies, while frequencies in the band range pass through.
D LP 6
This is a lowpass filter with a gentle, 6 dB/Octave slope. A lowpass filter is the op-
posite of a highpass filter. It lets the low frequencies through and filters out the
high frequencies. This filter has no Resonance.
D LP 12
This is a lowpass filter with a 12 dB/Octave roll-off slope.
D LP 24
This is a lowpass filter with a fairly steep roll-off slope of 24 dB/Octave.
Filter controls
The following filter controls are available:
D Freq
This is used for setting the filter cutoff frequency. The cutoff frequency determines
the limit above or below which frequencies will be cut off depending on the se-
lected filter type. In the case of a lowpass filter for example, frequencies below the
cutoff frequency will be allowed to pass through, while frequencies above it will be
cut off. The farther to the right you turn the knob, the higher the cutoff frequency
will be.
✪ It is very common to modulate filter frequency with the modulation enve-
lope, as described on page 180.
D Res
Technically, this knob controls feedback of the output signal from the filter, back to
its input. Acoustically it emphasizes frequencies around the cutoff frequency. For a
lowpass filter for example, increasing Res will make the sound increasingly more
hollow until the sound starts “ringing”. If you set a high value for the Res parameter
and then vary the filter frequency, this will produce a classic synthesizer filter
sweep.
For the notch and bandpass filter types, the Resonance setting instead adjusts the
width of the band. That is, the higher the resonance setting, the narrower the band
will be where frequencies are cut off (notch) or let through (Bandpass).
D K. Track
This lets you activate and control keyboard tracking of the filter frequency. If key-
board tracking is activated, the set cutoff frequency of the filter will change ac-
cording to the notes you play on your keyboard. That is, if you play notes higher up
on the keyboard, the filter frequency will be raised and vice versa.
When the knob is set to its center position, filter frequency is adjusted so that the
harmonic content remains constant across the keyboard.
Keyboard tracking is deactivated by default (the knob all the way to the left). This
means that the filter frequency will remain unchanged regardless of where on the
keyboard you play.