MuRF stands for "Multiple Resonance Filter Array". What this means is the MuRF has 8 filters - their levels are controlled by 8 sliders. It looks like a graphic eq, but the sound of the filters are very different: warm and resonant. The Heart of the MIDI MuRF is a bank of eight resonant bandpass filters tuned to fixed frequencies. The Animation module is a 24-Pattern sequencer triggering volume envelopes for the eight filters. The Freq Switch toggles between two banks of patterns; 12 bass patterns and 12 mid-range patterns.