Xone Series. VCF. Filters.
Posted by Chris Panks, Last modified by on 10 December 2008 04:41 PM

What do the VCF filters do? And how do you use them?

The Voltage Controlled Filter (VCF) section on the Xone:32 can be considered a sort of “super EQ”.
It can be used as an effect or a mix tool. The electronic circuitry is analogue (as opposed to digital signal processing 'DSP')

There are three basic filter types; 
Low-pass in which all frequencies above the cut-off point are filtered out,
Band-Pass in which frequencies above and below the cut-off point are filtered,
High-pass which filters all frequencies below the cut-off point.

The filters can also be added together by selecting two or more buttons simultaneously,
for instance, selecting high-pass and low-pass will produce a notch-filter (all frequencies at the cut-off point are filtered).
The sharpness of the cut-off point can also be changed using the “resonance” control.
With resonance on “mild” the filters will have a gentle roll-off around the cut-off point.
This will give a subtle filter sound, ideal for lifting out the bass line of one track as you mix in a new track, using the high-pass filter.

With the resonance set to “wild” the filter cut-off point is sharpened resulting in a much more aggressive sound,
best when using the filters as an effect.

On the Xone:32 the cut-off point of the filters is set by a 60mm fader,
low frequencies are on the left, high frequencies to the right.

Having a fader as a frequency controller allows some very wild effects to be achieved
and it is also easier to see where the filter frequency has been set.


The Xone:32 also has an LFO (low frequency oscillator).
The speed of the oscillator is set by a tap tempo button and an LED flashes green to indicate LFO speed or frequency.
When the LFO is switched on the LED will now flash red and green,
and the filter frequency fader switches over to be a depth control for the LFO,
i.e. with the fader fully to the right there will be no LFO modulation of the filter.

As it is moved left the LFO will have an increasing affect on the filter frequency.
The slowest speed the LFO will operate is about one cylcle over 4 bars of 120BPM.
The speed of the LFO can also be doubled by pressing the X2 button.
Hitting the tap tempo button once will re-sync the LFO. 

All of the filter and LFO switch settings can be stored in a non-volatile memory (DRS - Digital Recall System)
by pressing and holding one of the DRS buttons until the associated LED flashes once.
4 DRS switches are provided giving instant recall to 4 different filter settings.