User Manual

NN-19 SAMPLER
(RECORD+REASON)
633
Filter Mode
With this selector you can set the filter to operate as one of five different types of filter. These are as follows:
• 24 dB Lowpass (LP 24)
Lowpass filters lets low frequencies pass and cuts out the high frequencies. This filter type has a fairly steep roll-
off curve (24dB/Octave). Many classic synthesizers (Minimoog/Prophet 5 etc.) used this filter type.
• 12 dB Lowpass (LP 12)
This type of lowpass filter is also widely used in classic analog synthesizers (Oberheim, TB-303 etc.). It has a gen-
tler slope (12 dB/Octave), leaving more of the harmonics in the filtered sound compared to the LP 24 filter.
• Bandpass (BP 12)
A bandpass filter cuts both high and low frequencies, while midrange frequencies are not affected. Each slope in
this filter type has a 12 dB/Octave roll-off.
• High-Pass (HP12)
A highpass filter is the opposite of a lowpass filter, cutting out the lower frequencies and letting the high frequen-
cies pass. The HP filter slope has a 12 dB/Octave roll-off.
•Notch
A notch filter (or band reject filter) could be described as the opposite of a bandpass filter. It cuts off frequencies
in a narrow midrange band, letting the frequencies below and above through.
Filter Frequency
The Filter Frequency parameter (often referred to as “cutoff”) determines which area of the frequency spectrum the
filter will operate in. For a lowpass filter, the frequency parameter could be described as governing the “opening” and
“closing” of the filter. If the Filter Freq is set to zero, none or only the very lowest frequencies are heard, if set to max-
imum, all frequencies in the waveform are heard. Gradually changing the Filter Frequency produces the classic syn-
thesizer filter “sweep” sound.
! Note that the Filter Frequency parameter is usually controlled by the Filter Envelope (see “Envelope Section”
below) as well. Changing the Filter Frequency with the Freq slider may therefore not produce the expected re-
sult.
Resonance
The filter resonance parameter (sometimes called Q) is used to set the Filter characteristic, or quality. For lowpass fil-
ters, raising the filter Res value will emphasize the frequencies around the set filter frequency. This produces a gen-
erally thinner sound, but with a sharper, more pronounced filter frequency “sweep”. The higher the resonance value,
the more resonant the sound becomes until it produces a whistling or ringing sound. If you set a high value for the
Res parameter and then vary the filter frequency, this will produce a very distinct sweep, with the ringing sound being
very evident at certain frequencies.
• For the highpass filter, the Res parameter operates just like for the lowpass filters.
• When you use the Bandpass or Notch filter, the Resonance setting adjusts the width of the band. When you
raise the Resonance, the band where frequencies are let through (Bandpass), or cut (Notch) will become nar-
rower. Generally, the Notch filter produces more musical results using low resonance settings.