Sequential Unveils Fourm: Affordable 4-Voice Analog Synth with Polyphonic Aftertouch
Sequential has announced the Fourm, a powerful 4-voice analog synthesizer that brings classic Prophet-5 sound architecture to musicians at an accessible price point of $999. This compact instrument features polyphonic aftertouch - a capability Sequential hasn't offered in 40 years.
Key Features
The Fourm delivers 100% analog signal path through four voices of genuine Sequential sound, derived from the legendary Prophet-5. Each voice features dual SSI 2131 oscillators and a classic 4-pole lowpass filter with envelope curves modeled after the 1978 original.
The standout feature is the custom-designed Tactive™ slim-key polyphonic aftertouch keybed with 37 keys. This three-octave keyboard allows per-note expression, opening up new possibilities for dynamic performance. As professional keyboardist Bryn Bliska noted: "The polyphonic aftertouch is seriously so fun… Sequential nailed it."
Sound Design and Control
The synthesizer includes a modulation matrix inspired by the Pro-One, offering intuitive "knob-per-function" control without menu diving. Color-coded indicators provide visual feedback for modulation routings. Additionally, the Fourm features a multimode arpeggiator with step sequencer mode supporting up to 64 steps and polyphonic acid-style glide.
Compact Design
Despite its comprehensive feature set, the Fourm maintains a compact design. The steel chassis houses white, pink, and violet noise generators, a global LFO with seven wave shapes, and supports up to six polyphonic aftertouch destinations.
Market Impact
Sequential CEO David Gibbons explains the significance: "At a price-point that most people expect to pay for a monophonic synth, we think this product will invite legions of musicians who have longed for the magic of polyphonic analogue sounds to start their journey of discovery with Sequential."
The Fourm represents a strategic move to make Sequential's premium analog synthesis more accessible while maintaining the build quality and sound character the brand is known for. With MIDI and USB-C connectivity, it bridges classic analog warmth with modern production workflows.
The Sequential Fourm is available now for $999 USD.
