SonicLAB: Sequential FOURM Review

In our latest Sonic Lab review, we look at the Sequential FOURM, a new, more affordable four-voice analog synthesizer.

The FOURM has Prophet-5 style oscillators and filters, but in a compact form factor with a 37- slim key tactive key bed which has poly Aftertouch.

A nice solid case and firm knobs giveit a quality feel, though it doesnt have  onboard effects, and only a mono audio out,  to maintain an affordable price point of around £799.

The sequencer offers a 64-step polyphonic, though there's no parameter recording other than a single routable value.

FOURM represents a more affordable way into analog poly and the sound of the P5 though its not as fully featured as some other more digital based options.

Specs:

• Two Prophet-5 lineage analog oscillators per voice
• All oscillators have simultaneously selectable waveforms, including the LFO
• Oscillator B supports low frequency modes for use as polyphonic LFO modulation
• Classic Prophet-style Sync
• Variable square wave pulse width per oscillator (PWM)
• 4-Pole resonant lowpass filter drawn from the Prophet-5, revs 1 & 2
• Filter enhanced with bass compensation for thick sounds even with high resonance
• Filter can be driven into self-oscillation with the resonance control 
• Filter Keyboard tracking: quarter, half, full
• Feedback with an aggressive drive circuit for extra edge
• White, pink, and violet Noise types allow for greater sonic variation
• Four-stage (ADSR) filter envelope generator for tone shaping and assignable modulation
• Four-stage (ADSR) Amp envelope generator for volume shaping
• Velocity modulation of envelope amounts for dynamic performance
• One global LFO for creating movement in the sound
• Seven LFO wave shapes: sine, sawtooth, reverse sawtooth, square, S/H (sample and hold), Noise, and DC
• LFO can synchronize to tempo at different step values
• Four LFO wave shapes can be selected simultaneously for complex modulations

More Info:
- Sequential Website: Sequential https://www.sequential.com/

 

• Sequential Fourm - 4-Voice Analogue Synth with Polyphonic Aftertouch 23-Sep-25
• Sequential Take 5 Desktop Module Is Here 01-Jul-25
• Sequential Introduces Prophet-10 Special Edition 22-Oct-24
• Goodbye Prophet X 03-Apr-24
• Synthfest UK 2023: Calc And the Prophet X 09-Oct-23