The 16-voice EFM1 is a simple but powerful frequency modulation synthesizer. It can produce the rich bell and digital sounds that frequency modulation (FM) synthesis has become synonymous with.
If you’re new to synthesizers, see Synthesizer basics overview, which will introduce you to the terminology and give you an overview of various synthesis systems and how they work.
EFM1 is divided into several areas.
Global parameters: The top section contains parameters that set the overall tuning of EFM1. Further controls enable you to set the Glide (portamento) time, limit the number of voices, and thicken the sound with Unison. See EFM1 global parameters.
Modulator and Carrier parameters: The FM engine consists of the modulator and carrier parameters (raised, darker sections), and the FM Intensity knob (in the center). These are the key controls for setting the basic tone of EFM1. See Modulator and carrier overview.
Modulation parameters: The modulation envelope and LFO at the top and bottom of the mushroom-shaped area in the center respectively are used to animate the sound. See EFM1 modulation parameters.
Output parameters: The bottom section houses the Output section, which includes the Sub Osc Level and Stereo Detune knobs that can be used to thicken the sound. The volume envelope, Main Level, and Velocity controls are used to set the EFM1 level. See EFM1 output parameters.
Randomize parameters: The Randomize field and button in the lower-right corner are used to create random variations of the current settings, resulting in new sounds. See Create random EFM1 sounds.
Extended parameters: Accessed by clicking the disclosure triangle at the lower left of the interface, these parameters allow you to assign MIDI controllers to the FM Depth and Vibrato parameters. See EFM1 extended parameters and EFM1 MIDI controller assignments.