F_MEMBZ

F_MEMBZ — Membrane Percussion Synthesizer

Overview
F_MEMBZ is a physically inspired percussion module built around a vibrating membrane model. Instead of using a traditional oscillator, it excites a two-dimensional drumhead-like surface and reads the resulting motion as audio. The result can range from soft hand-drum and taiko-like hits to tighter, brighter, more bongo-like percussion, depending on membrane size, tension, decay, strike position, mallet hardness, body resonance, and snare-style buzz.

Concept
At the core of F_MEMBZ is a grid-based membrane solver. A strike injects energy into the virtual drumhead, that energy spreads across the membrane, reflects at the edge, and decays over time. Different settings change how the membrane reacts. Larger sizes lower the overall character, tighter tension raises it, edge loss controls how much energy dies off at the rim, and body resonance adds the sense of a shell or cavity around the membrane. A separate buzz layer can add snare-wire-like rattle on top of the membrane sound. Because the sound comes from interaction inside the model rather than from a fixed oscillator waveform, F_MEMBZ feels more like a physical instrument than a conventional synth voice.

Main Controls

• TENS adjusts membrane tension. Higher settings make the membrane tighter, brighter, and generally higher in pitch. Lower settings produce looser, deeper drum behavior.
• TUNE provides a broader pitch offset in musical terms. It shifts the overall tuning range of the membrane model without replacing the physical behavior of the membrane itself.
• DECAY controls decay. Lower values shorten the ringing and make the drum drier. Higher values allow the membrane to sustain longer.
• SIZE changes the effective size of the membrane. Larger settings produce a lower, heavier character. Smaller settings produce a tighter and more compact sound.
• EDGE controls how much energy is lost at the edge of the membrane. Higher values reduce sustain and make the drum die away faster at the rim. Lower values preserve more energy and allow longer ringing.
• BODY adds shell or cavity resonance. This can make the drum feel fuller, more hollow, or more physical, depending on the other settings.

Exciter Controls

• HIT sets the base strike strength.
• HIT X sets the horizontal hit position on the membrane.
• HIT Y sets the vertical hit position on the membrane.
• MALL controls mallet hardness. Lower settings are softer, rounder, and broader. Higher settings are harder, sharper, and more percussive.
• BUZZ adds a snare-wire-like rattle layer. Lower settings add a light buzz or rattle. Higher settings push the sound toward snare-like and noisy percussion behavior.
• LEVEL sets the final output level.

Canvas Interaction
The large membrane display is not only visual. You can click and drag on the membrane to choose a strike position, then release the mouse to trigger a hit at that location. This makes it easy to hear how center hits, off-center hits, and edge hits change the tone and attack. In general, strikes near the center are fuller and rounder, while strikes nearer the edge are lighter, sharper, and often more focused.

Inputs and Outputs

• PITCH is the pitch control input for the module.
• TRIG triggers a strike on the membrane.
• VEL CV modulates hit strength and can be used like a velocity input.
• OUT L / OUT R are the stereo outputs.

MOD Inputs
F_MEMBZ includes assignable modulation inputs. Each MOD slot can be routed to one of several meaningful parameters such as Tension, Tune, Decay, Size, Edge, Body, Hit, Hit X, Hit Y, Mallet, Buzz, or Level. This allows animated percussion, moving strike locations, evolving membrane behavior, dynamic body changes, snare-style buzz motion, and more advanced sound design without adding a dedicated CV jack for every parameter.

How Pitch Works
F_MEMBZ does not use a simple oscillator that directly follows a mathematically clean 1 volt per octave law. Instead, pitch emerges from the behavior of a membrane model. The module combines membrane tension, membrane size, strike position, decay behavior, body resonance, and global tuning into one physically inspired system. Because of that, pitch is influenced by several interacting parts rather than by a single ideal oscillator core.

Why It Is Not True V/Oct
A conventional V/Oct oscillator usually has one dominant frequency source that can be scaled exponentially in a very stable way. A membrane does not behave like that. A real or simulated drumhead contains many modes at once. Those modes do not all scale or dominate in exactly the same way, and the perceived pitch depends on which partials are strongest at a given moment. That means the apparent pitch can change not only with tuning input, but also with strike position, membrane size, decay, mallet hardness, body resonance, and buzz content. In other words, the module can be pitched and played musically, but it should not be expected to behave like a precision keyboard oscillator.

Practical Meaning of the Pitch Input
The PITCH input is intended as a useful musical pitch control, not as a guarantee of exact oscillator-grade tracking. It can move the membrane into higher or lower playing regions and can absolutely be used with sequencers, CV sources, and melodic patterns. However, because the sound is generated by a resonant membrane rather than a pure oscillator, exact semitone tracking across a wide range should not be expected. If you need strict tuning accuracy over a large melodic span, a conventional oscillator or modal synth voice is better suited. If you want physical, percussive, expressive behavior with musically steerable pitch, F_MEMBZ is designed for that.

How To Get Lower Drum Sounds

• Use a lower TENS setting.
• Use a larger SIZE setting.
• Use more BODY.
• Use moderate to high DECAY depending on how long you want the resonance to last.
• Use a softer MALL setting.
• Keep BUZZ low or off for pure membrane-style drums.
• Strike closer to the center of the membrane.

How To Get Brighter, Tighter Drum Sounds

• Raise TENS.
• Reduce SIZE.
• Use less BODY.
• Reduce DECAY for shorter, tighter hits, or keep it moderate for brighter ringing.
• Use a harder MALL setting.
• Strike further away from the center.
• Raise BUZZ if you want extra rattle or snare-like texture.

How To Get Snare-Like Sounds

• Use a medium or small SIZE.
• Set TENS in the middle to higher range.
• Use a moderate to fairly hard MALL setting.
• Raise BUZZ until the membrane begins to rattle like snare wires.
• Use DECAY to control how long both the drum and the buzz hang on.
• Try off-center hits for more edge and bite.

Performance Notes
Because F_MEMBZ is based on a physical membrane model, it responds well to modulation. Slow modulation of Hit X and Hit Y can create shifting percussion colors. Modulating Tension or Size can move the instrument between deep and tight membrane behaviors. Modulating Body can add motion to the shell resonance. Modulating Buzz can move the sound between clean drumhead tones and snare-like rattle textures. The module is particularly effective for hand drums, experimental percussion, snare-style sounds, tuned membrane textures, and animated stereo percussion layers.

Stereo Behavior
F_MEMBZ provides stereo output by reading different areas of the membrane and combining them into left and right signals. This gives the module a wider and more spatial response than a simple mono pickup. Subtle differences in membrane motion and strike position help create a more lively stereo image.

Summary
F_MEMBZ is not a drum sample player and not a plain oscillator with a click envelope. It is a playable membrane instrument. Use Tension, Tune, Size, Decay, Edge, and Body to shape the drum itself, then use Hit, Hit X, Hit Y, Mallet, and Buzz to shape how it is played and how it rattles. Treat the pitch input as a musical control rather than a strict V/Oct standard, and F_MEMBZ becomes a flexible source of physical percussion, snare-like drum voices, tuned membrane sounds, and expressive membrane-based sound design.