Sequential Fourm: A New Gateway into Iconic Analog Sound

With the launch of the Sequential Fourm, Sequential has opened up a fresh chapter in its storied history—delivering its characteristic analog warmth and expressive tools in what the company calls its most affordable synthesizer to date. For many musicians and synth enthusiasts, Fourm may well represent the sweet spot where classic timbre meets practical price. Here’s a closer look at what makes this synth special, how it fits into Sequential’s lineage, and what it might mean for creators.

The Pitch: Value + Heritage

Sequential introduced Fourm on September 23, 2025. It’s a compact, 100 % analog polysynth designed to bring some of the magic of their higher-end instruments—like the Prophet-5—into a more accessible format. 

The marketing emphasizes expressive performance (especially via polyphonic aftertouch), hands-on control (modulation routing on the top panel), and a voice architecture inspired directly by older classics. 

At a street price around US$999 / £799 / €949, Fourm undercuts many of Sequential’s previous polyphonic analog synths, making it more reachable. 

What You Get: Specs & Features

Here are the key specs and capabilities of Fourm that justify the buzz:

• Polyphony: 4 voices. Enough to play chords, pads, and layered textures, though it’s not in the same class as 8-voice monsters.

• Oscillators: Dual analog oscillators per voice with simultaneously selectable waveforms; oscillator 2 also usable as a low-frequency oscillator (LFO) in some modes. 

• Filter: A classic 4-pole low-pass resonant filter—again, invoking the Prophet-5 lineage. The envelope curves are modeled on the 1978 original Prophet-5. 

• Modulation: Top-panel modulation matrix inspired by the Pro-One. Users can route sources (filter envelope, oscillator B, aftertouch, LFO) to various destinations without deep menu diving. Color-coded destination buttons help with clarity. 

• Polyphonic Aftertouch: A big deal. Sequential has reintroduced polyphonic aftertouch for the first time in decades, via a newly developed “Tactive™ slim-keys poly AT keybed.” Expressivity is a key selling point. 

• Performance & Utility Features:

  • Overdriven feedback circuit to add grit or aggressive tones. 

  • Arpeggiator + 64-step sequencer mode (via arp). 

  • Glide modes, including options similar to 303-style glides per step. 

• Build & Interface: 37-note slim keys (for space saving and more compact footprint), housed in a steel chassis. MIDI IN/OUT/THRU, USB, footswitch/pedal input, etc. 

What’s New / What’s Shared

Some features are clearly inherited from Sequential’s legacy; others are new or adjusted to hit the price point.

• Shared DNA: Prophet-5 influence is everywhere—in voices, filter behavior, envelopes. The modulation approach, classic 4-pole filter, etc., are part of what gives Fourm its familiar tonal character. 

• New engineering: The Tactive slim-keys polyphonic aftertouch keybed is newly developed in-house, calibrated especially to match the analog engine. That’s not a trivial feature; many synths at similar prices omit poly-AT entirely due to cost and complexity. 

• Cost trade-offs: As with any product trying to squeeze high performance into lower price, there are limits. Only four voices, no built-in effects (or at least the effects are limited). For some, the slim-key keyboard might feel less satisfying than heavier, full-size keys. Some people expect deeper layering, stereo effects, or more modulation destinations, but part of the design decision was clearly balancing cost vs performance. 

Where It Fits: Who It’s For

Fourm seems targeted at a few overlapping groups:

1. Intermediate & Advanced Players Seeking the Classic Sequential Sound
   If you’ve admired the Prophet family, or older Sequential analog polys, and wanted something more affordable—this might be the entry point. You get heritage, character, and expressive control without the price tag of full Prophet-series or high-end analog polys.

2. Live Performers / Expressive Players
   With polyphonic aftertouch, responsive keys, feedback circuits, modulation matrix, etc., Fourm offers real performance tools. Even with 4 voices, expressive playing (chord voicings, dynamic touch, etc.) makes a difference.

3. Bedroom Studios / Electronic Producers
   For someone building a synth rig, Fourm gives you a real analog voice, flexible modulation, sequencer/arpeggiator, and direct hands-on control. It can help avoid overreliance on plugins, and add character and color in ways analog often does so well.

4. Beginners / Budget Buyers Wanting “Real Analog”
   Though the price isn’t cheap in absolute terms, for Sequential and for analog polysynths, this is competitive. As a first analog poly from a major heritage brand, it could be a defining experience.

What to Consider: Limitations & Compromises

No synth is perfect, and Fourm is no exception. Depending on your needs, some trade-offs might matter more than others:

• Voice Count: Four voices are solid, but limit thick pads, very dense layering, or dividing parts. If you want 8 or 16-voice polys, or to run multiple layers, you’ll hit limits.

• Effects / Processing: The unit does not include (or includes very minimal) built-in effects like reverb, delay, chorus, etc. For lush ambience or spacey effects you may need external or plugin support. MusicRadar

• Key Feel: Slim keys save space, reduce weight, reduce cost—but for some, they lack the tactile feel of full-size, heavier, premium keybeds. Also, while polyphonic aftertouch is a big plus, adapting technique to use it takes practice.

• Size vs Expandability: The compact footprint and fewer voices are good for portability and price, but not for massivemusical ambits or layering multiple patches live in a big rig.

What this Means for the Synth Market & Sequential’s Strategy

Fourm suggests a few trends/moves in Sequential’s roadmap—and in the analog synthesizer market generally:

• The heritage brands are increasingly working to democratize analog polyphonic sound—not just for flagship studio units or high-end live rigs, but for more affordable desktop or stage tools. Fourm is a clear example.

• Expressive controllers (like polyphonic aftertouch) and performance features are again being prioritized—not just sound-color, but feel and nuance matter.

• Modulation and hands-on control remain central differentiators. The ability to route modulation without digging through menus is a big selling point. Fourm’s top panel matrix and color indicators show attention to usability.

• Pricing remains a live challenge. Balancing cost of analog circuits, keybeds, panel controls, and the needed hardware (chassis, connectivity) is non trivial. Fourm strikes a balance that many will consider fair.

Verdict: Is Fourm the Right Choice?

If I were advising someone, here’s how I’d decide whether Fourm is right for them:

• Yes, if you want classic Prophet/Squential-style analog sound, and you value expressive performance (aftertouch, modulation) but don’t need massive polyphony or built-in effects.

• Maybe, if you want lush ambient effects onboard, or huge layering, or heavier keys—or if you frequently need 8+ voices live.

• Not the best pick, if your main goal is maximum voices for pads, or you need a full-size keybed, or deep effects chain embedded.

Overall, Fourm looks like it succeeds at its promise: giving more people access to genuine Sequential analog polyphonic sound, with performance tools and a tactile interface—at the lowest price Sequential has offered for a synth.

Final Thoughts

Sequential Fourm marks a noteworthy step in making analog polys more accessible without giving up what makes them special. Heritage, expression, sound warmth—all of that is there. It’s not perfect or all-things-to-all-people, but as a “gateway” synth it’s possibly one of the strongest we’ve seen in a long time. For creators, the Fourm might not just represent “the first Sequential polysynth I can afford,” but a meaningful instrument in its own right.