A filter filters out certain frequencies in the sound. There are four main types: a low-pass, high-pass, band-pass and notch, which are covered elseware in the glossary. Filters have two controls - the frequency control selects at which frequency the filter should start operating and the resonance control creates a peak just before the bit where it starts filtering out frequencies. This is used to create acid-type sounds....
Matrix-6
This synthesizer was based on the popular Matrix line. The Matrix-6 is basically a
stripped down Xpander with a 5-octave, 31-note (C-C) keyboard, which features on and
off velocity, as well as channel aftertouch. It features 6-note polyphony and pitch and
modulation levers (not wheels) to the left of the keyboard. Each voice has two DCOs (as
opposed to the Xpander's VCO), a VCF, three envelope generators (5 stage: Delay,
Attack, Decay, Sustain, Release), two ramp generators (simple envelopes), tracking
(not just for the keyboard but for remapping any modulation source), portamento and
FM controls, three LFOs, and two VCAs. Along with other "Matrix" products from
Oberheim, the Matrix-6 features what Oberheim called, "Matix Modulation System",
which makes for very flexible and powerful modulation programming. With this much
programmability it is unfortunate that the only user interface is a single slider and a
keypad.