Neuro Synth User Guide

A beginner-friendly guide to sound design with the Neuro synthesiser.

1. Introduction

What Is Synthesis?

Synthesis is the art of creating sound electronically. Instead of recording a real instrument, a synthesiser builds sound from basic building blocks — oscillators that generate raw waveforms, filters that shape the tone, and envelopes that control how the sound changes over time.

The Neuro synth is a subtractive synthesiser designed for bass and sound design, particularly in drum & bass, neurofunk, and related genres. It takes a simple approach: generate rich waveforms, carve away what you don't need with filters, add movement with modulation, and polish the result with effects and compression.

The Neuro Synth at a Glance

  • Two main oscillators with frequency modulation (FM), wavefolding, and sync
  • A detuned "Reese" voice bank for thick layered sounds
  • A sub oscillator for bass weight
  • A multi-colour noise generator
  • An 8-type multimode filter with envelope and LFO modulation
  • A 9-target LFO for simultaneous modulation
  • A distortion pipeline with 9 drive types
  • Multiband OTT compression
  • A dynamics compressor with sidechain and parallel mix
  • A 3-band clarity processor for cleaning up muddiness
  • RMS/peak normalisation for WAV export

How This Guide Is Structured

Each section explains a concept, then shows how the Neuro synth implements it. You don't need to read everything at once — jump to whatever interests you.

2. Getting Started

Opening the Synth

Navigate to /synth/neuro in your browser. The page is split into three areas:

  • Main content (left): the waveform display and all synthesiser controls
  • Sidebar (right): presets — load built-in sounds or save your own
  • Footer: the piano keyboard, octave controls, BPM, transport buttons

"Tap to Initialise"

The first time you visit the page, you may see a "Tap to Initialise" banner. This is because your browser suspends the audio system until you interact with the page. Tap it to wake the audio engine. You only need to do this once per page load.

Playing Your First Note

You can play notes in three ways:

  1. Mouse: click the piano keys in the footer
  2. Keyboard: use your computer keyboard (see §19 for the key map)
  3. Touch: tap the piano keys on a touch screen

Octave and BPM

  • The octave buttons (◄ Octave 2 ►) shift the keyboard range up or down
  • Press + or − on your keyboard to change octave
  • Press 1–9 to jump to that octave directly
  • Click the BPM label to set the tempo (affects LFO sync and exported file naming)

3. Sound Is Vibration

Before diving into the controls, here's a quick refresher on what you're actually manipulating:

Frequency — Pitch

Frequency is how fast something vibrates, measured in Hertz (Hz). - 20 Hz is a very low rumble (the lowest notes on a subwoofer) - 440 Hz is A4 (the tuning note orchestras use) - 20,000 Hz (20 kHz) is the upper limit of human hearing

Amplitude — Volume

Amplitude is how big the vibration is, measured in decibels (dB). - 0 dB is the loudest possible level without distortion - −6 dB is half as loud - −60 dB is very quiet, close to silence

Waveform — Timbre

The shape of the vibration determines the character of the sound — what makes a trumpet sound different from a flute playing the same note:

Waveform Sound Harmonics
Sine Pure, flute-like, smooth No extra harmonics (fundamental only)
Triangle Soft, slightly buzzy Odd harmonics, quiet
Sawtooth Bright, buzzy, "synth-like" All harmonics (even + odd)
Square / Pulse Hollow, reedy, "video-game-like" Odd harmonics only

The Signal Chain

Every sound you hear flows through this path:

Oscillators → Filter → Distortion → EQ → OTT → Compressor → Clarity → Amplifier

You can think of it like a factory: 1. Oscillators make the raw material 2. Filter carves away unwanted frequencies 3. Effects (distortion, compression, clarity) refine the sound 4. Amplifier (the volume envelope) controls when you hear it

Mono Output

Everything in the Neuro synth processes in mono (a single channel). The stereo spread control pans oscillators left and right, but the signal is summed to mono — the "width" you hear is a side-effect of phase differences, not true stereo separation.

4. The Oscillator Section — Making Sound

What Is an Oscillator?

An oscillator is an electronic circuit that produces a repeating waveform. Every musical note starts here. The Neuro synth has two main oscillators that can work together to create rich, complex tones.

Osc1 and Osc2 — Two Sound Sources

Each oscillator has its own waveform, detune, level, and wavefolder.

Waveform Pills

Click the pill buttons to change the waveform type:

  • Sawtooth: the classic synth bass waveform — bright and full
  • Square: hollow and reedy — great for pulse-width modulation
  • Triangle: softer than sawtooth, good for blending
  • Sine: pure and clean — no extra harmonics

Try setting both oscillators to different waveforms and adjusting their levels. A common trick: sawtooth on Osc1 for bite, sine on Osc2 for sub weight.

Cents — Fine Detuning

The Detune1 and Detune2 sliders shift each oscillator's pitch by a tiny amount, measured in cents (100 cents = 1 semitone). Detuning two oscillators against each other by 5–15 cents creates a thick, chorused effect. This is the foundation of the "Reese" bass sound.

Levels

Level1 and Level2 control the volume of each oscillator before they reach the filter. If one oscillator overpowers the other, turn it down here rather than in later stages.

FM — Frequency Modulation

FM uses one oscillator to modulate the pitch of the other at audio rate. The result is a complex, metallic, or glassy texture depending on the amount.

  • FM Amt: how much Osc2 affects Osc1's frequency
  • FM Mode:
  • Exponential (exp): warmer, more musical — the modulation depth naturally follows the pitch. Best for bass.
  • Linear (lin): cleaner and more predictable — the modulation depth is constant regardless of pitch. Better for precise FM tones.

At low amounts (0.1–0.3), FM adds a subtle sheen. At high amounts (0.5+), it creates aggressive, clanging tones.

Pulse Width — Shaping the Square Wave

When the waveform is set to square, the PW (Pulse Width) slider controls the duty cycle — the ratio of time the wave spends "on" vs "off".

  • 0.5 = a perfect square wave (equal on/off time)
  • 0.1 = a very narrow pulse (thin, nasal sound)
  • 0.9 = a very wide pulse (also thin, different character)

PWM (Pulse Width Modulation) uses an internal LFO to continuously sweep the pulse width, creating a warm, moving, chorused effect. Set PWM rate to control the speed and PWM depth to control how much the width changes.

Wavefolding — Adding Harmonics

A wavefolder bends the waveform back on itself when it reaches a certain level, creating extra harmonics without changing the fundamental pitch. It's like distortion, but cleaner and more musical.

  • Fold1 / Fold2: independent folding for each oscillator
  • At 0: no folding (clean waveform)
  • At 0.3–0.6: subtle harmonic enhancement
  • At 0.8+: aggressive, buzzy, chaotic

Hard Sync — Cross-Modulation

Sync routes Osc2's output into Osc1's frequency at audio rate. This creates aggressive, metallic, or "tearing" sounds — think Pendulum or Noisia-style bass tones.

At low settings, it adds a slight edge. At high settings, the sound becomes unstable and chaotic.

Feedback FM — Self-Oscillation

FB Amt (Feedback) routes Osc1's output back into its own frequency modulation. At low amounts, it adds harmonic complexity. At high amounts, it self-oscillates and can create noise-like textures.

Use with caution — high feedback can be very loud!

Spread — Stereo Width

Spread pans Osc1 to the left and Osc2 to the right. The signal is eventually summed to mono, but the panning creates phase differences that add perceived width.

At 0: both oscillators centred At 1: Osc1 hard left, Osc2 hard right

Common Neurofunk Oscillator Techniques

  • The "Reese" foundation: both sawtooth, detuned 5–10 cents, spread at 0.3–0.5, light folding (0.2–0.3)
  • FM growl: Osc1 sawtooth, Osc2 sine, FM amount 0.3–0.6, sync at 0.2
  • PWM movement: square wave on one oscillator with PWM rate 2–4 Hz, depth 0.2–0.4
  • Feedback texture: feedback FM at 0.1–0.3 adds grit without losing pitch definition

5. The Reese Section — Thick Detuned Layers

What Is a Reese?

A "Reese" (named after the track by Terminator) is a bass sound made by layering multiple detuned sawtooth oscillators. As they drift in and out of phase, they create a thick, pulsating "wall of sound."

Controls

  • Voices: how many detuned voices (1–8). More voices = thicker, but also more CPU intensive.
  • Detune: how far apart the voices are spread in cents. 10–20 cents is typical for a warm Reese. Higher values create a chorus-like effect.
  • Mix: the volume of the Reese layer relative to the main oscillators.

How It Works

The Reese voices use the same waveform as Osc1. Each voice is spread evenly across the detune range — for example, with 3 voices and 12 cents detune, the offsets are −12, 0, and +12 cents from the base frequency.

The pulsing "beat" you hear is the acoustic beating between the detuned voices. The rate of the pulse depends on the detune amount and the pitch of the note.

6. The Sub Section — Low-End Foundation

What Is a Sub Oscillator?

A sub oscillator is a dedicated sound source tuned to the same pitch as your main oscillators (or one octave below). Its purpose is to add clean, solid low-end weight without muddying the main sound.

Controls

  • Wave: sine (pure sub — no harmonics) or triangle (slightly more presence, easier to hear on small speakers)
  • Level: the sub's volume
  • Octave: 1 (same pitch) or 2 (one octave below)

When to Use a Sub

  • Add a sine sub to a Reese to give it bass weight
  • Use a triangle sub when the sine is too quiet on phone speakers
  • Set the sub octave to 2 for deep, rumbling tones

7. The Noise Section — Texture and Grit

What Is Noise?

Noise is a random signal that contains many frequencies at once. Synthesisers use noise for percussive elements (hi-hats, snares), textures (wind, static), and adding grit to bass sounds.

Types of Noise

The Neuro synth generates noise from scratch every time you play a note, then shapes it through filters and effects:

Type Character Best For
White Flat, all frequencies equal (like radio static) Hi-hats, snares, percussive attack
Pink More low-end, less hiss (natural sounding) Textures, atmospheres, risers
Brown Deep, rumbly (like thunder or ocean) Subby noise, impacts, drones

Controls

  • Level: overall volume of the noise
  • Color: a continuous sweep from dark to bright
  • 0: dark (lowpass at ~100 Hz — brown-like)
  • 0.5: flat (no filter — white)
  • 1: bright (highpass at ~6 kHz — airy)
  • Cut: an additional lowpass filter that progressively darkens the noise
  • Crush: sample-rate decimation — reduces the resolution of the noise
  • 0: clean
  • 0.5: lo-fi, crackly
  • 1: extreme stutter (1 sample per step)
  • Layer2: crossfades to a second independently-coloured noise layer for complex, evolving textures
  • Color2: colour of the second layer

Using Noise in Bass Sounds

Noise is typically used as a transient layer — a short burst at the start of a note to add attack and presence. Set the level to 5–15 %, and pair it with a fast envelope on the filter to make the noise "breathe."

8. The Filter Section — Shaping the Tone

What Is a Filter?

A filter removes or boosts specific frequency ranges. It's the most important tool for shaping the character of a sound. The Neuro synth has an 8-type multimode filter with adjustable slope.

Filter Types

Type Icon What It Does
Lowpass LP Lets low frequencies through, cuts highs. The classic synth filter.
Highpass HP Lets highs through, cuts lows. Great for thinning sounds.
Bandpass BP Lets a narrow band through, cuts everything else. Very nasal.
Lowshelf — Boosts or cuts all frequencies below the cutoff. EQ-like.
Highshelf — Boosts or cuts all frequencies above the cutoff.
Peaking — Boosts or cuts a specific frequency band. Like an EQ.
Notch — Removes a narrow frequency band. Surgical.
Allpass — Shifts phase without changing volume. Subtle.

For bass synthesis, you'll mostly use lowpass and highpass.

Key Controls

  • Cutoff: the frequency where the filter starts to act
  • Low (20–500 Hz): dark, muffled
  • Mid (500–2000 Hz): warm or honky
  • High (2000+ Hz): bright, thin
  • Res (Resonance / Q): Emphasises frequencies around the cutoff
  • Low (0–0.3): subtle
  • Medium (0.3–0.7): noticeable peak
  • High (0.7+): can self-oscillate at the cutoff frequency (a whistling tone)
  • Gain: boost or cut for shelf and peaking types (not used by LP/HP/BP)
  • Slope: how steeply the filter removes frequencies
  • 12 dB: gentler rolloff — more of the unwanted frequencies bleed through, sounds more natural
  • 24 dB: steeper rolloff — removes frequencies more aggressively, sounds more dramatic

The Filter Envelope (Env→Cut)

The Env→Cut slider controls how much the volume envelope (ADSR) affects the filter cutoff. When you press a key:

  1. The envelope starts (attack)
  2. The filter opens (cutoff rises by envAmount semitones)
  3. The filter closes back to its base cutoff (decay)

A high env amount with a low cutoff creates the classic "wobble" bass sound: the filter opens and closes with each note.

Common Filter Techniques

  • Lowpass sweep: start with cutoff at 200 Hz and res at 0.5, then sweep the cutoff up for a classic "open filter" effect
  • Highpass for thinning: remove low-end rumble from a sound by setting a highpass filter at 100–300 Hz
  • Peaking for presence: boost around 1–3 kHz with a peaking filter to make a bass cut through a mix
  • 24 dB for aggression: use the steeper slope for more dramatic filter sweeps in neurofunk basses

9. The LFO Section — Modulation

What Is an LFO?

LFO stands for Low-Frequency Oscillator. It's an oscillator that produces a slow, repeating waveform — too slow to hear as a pitch, but perfect for modulating other parameters.

Think of it like an automatic hand that turns a knob back and forth for you.

Rate and Sync

  • Rate: how fast the LFO cycles (0.1–20 Hz)
  • 0.1 Hz: one cycle every 10 seconds (slow)
  • 2 Hz: two cycles per second (classic wobble)
  • 10+ Hz: fast enough to create audible effects
  • Sync: locks the LFO rate to your project tempo
  • 1/1: one cycle per beat
  • 1/4: four cycles per beat (quarter-note triplets)
  • 1/16: sixteen cycles per beat (sixteenth notes)

Waveforms

Wave How It Moves Sound
Sine Smooth up and down Gentle, natural modulation
Triangle Straight-line up and down Like sine but more pronounced
Sawtooth Ramp up, jump down Aggressive, "laser" effect
Square Jump between two values Stepped, trill-like
S&H (Sample & Hold) Random value each cycle Stepped, random, "computer"

Delay — Fade-In

Delay adds a fade-in time before the LFO reaches full depth. The LFO starts at 0 and ramps up over the delay period.

This is especially useful for vibrato on held notes — the pitch stays steady when you first press a key, then the vibrato fades in after a second or two.

Bipolar / Unipolar

  • Bipolar: the LFO swings above AND below the centre value (the classic ±1 LFO)
  • Unipolar: the LFO only swings upward from the centre (0→+1)

Unipolar is useful for modulating things like filter cutoff or volume where you only want to increase the value, never decrease it.

Modulation Targets

The Neuro synth lets you modulate multiple targets at the same time. Each target has its own depth slider — set a depth to 0 and that target is not modulated.

Target What It Modulates Effect
Cut Filter cutoff frequency Classic filter wobble
Pitch Oscillator pitch Vibrato
FM FM amount Changing FM depth over time
Fold Wavefolder drive Dynamic harmonic complexity
Pan Stereo pan position Auto-pan (note: output is mono)
Noise Noise colour filter Sweeping noise tone
Res Filter resonance Wah-like effect
Level Overall amplitude Tremolo (volume pulsing)
Sub Sub oscillator level Sub bass pulse

Quick LFO Tips

  • Cut wobble: sine wave, depth 0.5–1.0, rate synced to 1/8 or 1/16
  • Vibrato: pitch at depth 0.1–0.3, sine wave, delay 0.5–1.0 s
  • Tremolo: level at depth 0.3–0.6, sine or triangle wave
  • Auto-wah: res at depth 0.3–0.5, sine or triangle wave
  • Random filter: S&H wave on cut at depth 0.5–1.0, rate 1–4 Hz

10. The Envelope Section — Shaping Over Time

What Is an ADSR Envelope?

An envelope controls how a sound changes from the moment you press a key to the moment you release it. ADSR stands for Attack, Decay, Sustain, Release — the four stages of a note's life.

  Press        Release
    ↓            ↓
    ┌──┐
    │  │        ┌──┐
    │  │┌──────┐│  │
    │  ││      ││  │
    │  ││      ││  │
    └──┘└──────┘└──┘
    A  D   S    R
  • Attack: how long it takes for the sound to reach full volume after pressing a key (0.001–1 s)
  • Short (0.001–0.01): instant — percussive
  • Long (0.5+): slow fade-in — pad-like
  • Decay: how long it takes to drop from full volume to the sustain level (0.01–0.5 s)
  • Sustain: the volume level held while the key is pressed (0–1)
  • 1: the sound stays at full volume
  • 0: the sound fades to silence (percussive)
  • Release: how long it takes for the sound to fade after releasing the key (0.001–3 s)

Keyboard Mode vs Sequencer Mode

When you play the Neuro synth with the keyboard (mouse, computer keys, or touch), the envelope holds at the sustain level until you release the key — you can hold a note indefinitely. When the sequencer triggers a note, the full ADSR plays automatically with a fixed duration.

Common Envelope Shapes

  • Percussive: short attack (0.001), short decay (0.05), no sustain (0), short release (0.05)
  • Bass note: short attack (0.005), medium decay (0.1–0.3), medium sustain (0.3–0.6), medium release (0.1–0.3)
  • Pad: slow attack (0.5+), medium decay, high sustain (0.7–1), long release (1+)
  • Pluck: very short attack, quick decay, no sustain, no release

11. The EQ Section — Tonal Balance

What Is an EQ?

An EQ (equaliser) lets you boost or cut specific frequency ranges. The Neuro synth has a simple 3-band EQ placed before the distortion and compressor.

The Three Bands

Band Type Centre Effect
Low Lowshelf 250 Hz Boosts or cuts the low end (sub and bass)
Mid Peaking 1 kHz Boosts or cuts the mid-range (presence, body)
High Highshelf 8 kHz Boosts or cuts the high end (air, brightness)

When to Use EQ vs Filter

The filter and EQ are in different parts of the signal chain:

  • Filter before distortion: the filter shapes the sound before distortion adds harmonics. This is where you carve away unwanted frequencies for the main tonal character.
  • EQ before compressor: the EQ adjusts the balance of frequencies before the compressor reacts to them. Boosting 1 kHz will make the compressor respond more to the mid-range.

A common approach: use the filter for broad shaping and the EQ for fine-tuning.

12. The Distortion Section — Adding Harmonics

What Is Distortion?

Distortion clips or reshapes the waveform, adding new harmonics that weren't there before. This makes a sound brighter, grittier, and more aggressive.

The Neuro synth uses a WaveShaperNode — a curve that maps each input sample to an output value. The shape of the curve determines the character of the distortion.

Distortion Types

Type Character Best For
Soft Clip Gentle, warm rounding Saturation, subtle harmonics
Hard Clip Aggressive, harsh Heavy distortion, "broken" sound
Tape Smooth, compressed Warm, vintage saturation
Tanh Musical, smooth Clean saturation, "analogue" warmth
Exponential Asymmetric, complex Rich, unpredictable harmonics
Bitcrush Digital, lo-fi 8-bit video game sounds
Wavefold Bright, metallic Extreme harmonic generation
Full-wave Rectify Doubles the frequency Octave-up effect

Controls

  • Type: choose from the 9 drive types
  • Amount: the intensity of the distortion curve (0–1)
  • Drive: pre-gain that pushes the signal harder into the distortion (1–10×). Higher drive = more aggressive distortion.

Stacking Multiple Stages

You can add up to 5 distortion stages in series. Each stage processes the output of the previous one. Try a light Soft Clip stage followed by a Tape stage for a warm, heavily-saturated sound.

Master Lock

The master lock (🔒) freezes the entire distortion section so that randomisation won't touch it. Use it when you've dialled in a distortion sound you want to keep.

13. The OTT Section — Multiband Compression

What Is Multiband Compression?

A standard compressor works on the whole frequency range at once. A multiband compressor splits the signal into separate frequency bands and compresses each one independently.

The OTT Effect

OTT (named after Xfer Records' popular plugin) uses three bands: - Low: ≤250 Hz - Mid: 250–4000 Hz - High: ≥4000 Hz

Each band has two compressors: - Downward compressor: reduces loud parts above the threshold - Upward compressor: brings up quiet parts below the threshold

The result is a very aggressive, "in-your-face" sound that adds presence and detail.

Controls

  • Depth: how much of the processed signal is mixed with the original (0–1). 0.3 is subtle, 0.6 is noticeable, 1 is full OTT.
  • Down: downward compression amount (advanced mode)
  • Up: upward compression amount (advanced mode)
  • Attack/Release: how fast the compressors react

14. The Compressor Section — Dynamics Control

What Is a Compressor?

A compressor automatically reduces the volume of a signal when it exceeds a threshold. This makes the sound more consistent and controlled.

Key Controls

  • Threshold: the level at which compression starts (−60 to 0 dB). Set it lower to compress more of the signal.
  • Ratio: how much compression is applied once the signal exceeds the threshold (1:1 to 20:1)
  • 2:1: gentle — every 2 dB over the threshold becomes 1 dB
  • 10:1: heavy — almost limiting
  • 20:1: brickwall — nothing gets through louder than the threshold
  • Attack: how fast the compressor reacts (1–100 ms)
  • Fast (1–5 ms): catches transients, tightens the sound
  • Slow (20+ ms): lets transients through, preserves punch
  • Release: how fast the compressor recovers (10–1000 ms)
  • Fast (10–30 ms): can cause distortion
  • Medium (50–200 ms): musical, general purpose
  • Slow (500+ ms): keeps the volume consistent

Additional Features

  • Knee: softens the onset of compression (0–40 dB). Higher values make the compression feel more gradual and natural.
  • Makeup: boosts the output level to compensate for the volume reduction from compression (0–24 dB). Essential for A/B comparison.
  • Mix: blends the compressed signal with the original (0–1). This is called parallel compression. 100 % = fully compressed, 50 % = half compressed, 0 % = dry (bypassed).

Sidechain HPF (SC HPF)

The sidechain highpass filter prevents low frequencies from triggering compression. When enabled, the compressor's detection circuit hears a highpass-filtered version of the signal — low-end rumble won't cause the compressor to clamp down on the whole sound.

Common use: compress a bass sound so that only the mid-range and above trigger the compressor, leaving the sub-bass solid and uncompressed.

The GR (Gain Reduction) Meter

The GR meter below the compressor controls shows the estimated maximum gain reduction based on your threshold and ratio settings. The formula is:

GR = |threshold| × (1 − 1/ratio)

For example: threshold = −24 dB, ratio = 4:1 → GR = 24 × (1 − 0.25) = 18 dB max reduction

The bar turns from green to amber to red as the reduction increases.

15. The Clarity Section — Cleaning Up Muddiness

What Is Mud/Air Reduction?

Certain frequency ranges can make a sound "muddy" (~350 Hz), "boxy" (~1.2 kHz), or "harsh" (~4 kHz). The Clarity section identifies these problem areas and compresses them independently, cleaning up the sound without affecting the rest of the frequency spectrum.

The Three Bands

Band Range Target Problem It Fixes
Mud 200–800 Hz ~350 Hz Low-mid muddiness — makes the bass unclear
Mid 500–3000 Hz ~1.2 kHz Boxiness — makes it sound like a phone speaker
Air 2000–8000 Hz ~4 kHz Harshness — sibilance, piercing highs

Each band has its own set of controls:

  • Freq: the centre frequency of the bandpass filter
  • Q: the bandwidth (higher = narrower band)
  • Thresh: compressor threshold
  • Ratio: compression ratio
  • Attack/Release: compressor timing
  • Makeup: post-compression gain boost

Listen/Solo

Click the Listen pill on a band to hear ONLY that band in isolation. This is incredibly useful for dialling in the right frequency — you can hear exactly what that band is capturing before you start compressing it.

Phase Invert

Phase inverts the polarity of the band (flips it 180°). Bandpass filters introduce phase shifts, which can cause cancellation when the processed signal is mixed back with the dry signal. Inverting the phase can fix this.

Bypass

Bypass routes the band's signal around the compressor, leaving the band's filter active but skipping the dynamics processing. The band still passes through to the output, just uncompressed.

Wet Only

Wet Only mutes the dry signal so you hear ONLY the processed clarity bands. Use this to fine-tune the compressor settings for each band, then turn it off to hear the blended result.

SC HPF (Sidechain)

The SC HPF slider puts a highpass filter before every band's compressor. Frequencies below the cutoff won't trigger the clarity compressors — useful if your bass has heavy sub content that shouldn't affect the mud/air reduction.

16. The Normalise Section — Export Level

What Is Normalisation?

When you export a WAV file, normalisation analyses the audio and turns up the volume so the loudest peak hits a target level. This ensures your export is as loud as possible without clipping.

Peak vs RMS

  • Peak normalisation: finds the single loudest sample and sets the gain so that sample hits the target level. Simple and reliable, but doesn't account for perceived loudness.
  • RMS normalisation: finds the average (RMS) level of the audio and scales it to the target. This gives a more consistent perceived loudness — useful for comparing mixes at the same level.

Controls

  • Target: the level the loudest peak (or RMS) will hit after normalisation (−12 to 0 dB)
  • −1 dB: standard for mastering (leaves a little headroom)
  • −0.1 dB: maximally loud
  • −6 dB: conservative, for further processing
  • Ceiling: after normalisation, hard-clip any sample that exceeds the target level. This prevents inter-sample peaks.
  • Remove DC: removes any DC offset (a constant electrical shift) from the audio before normalising. DC offset can cause clicks and pops.

When Normalisation Runs

Normalisation only runs during WAV export (not during live playback). The normalisation meter shows the pre-level, target level, and applied gain from the most recent render.

17. The Spectrum Analyser — Visual Feedback

What You're Seeing

The spectrum analyser at the bottom of the page shows the frequency content of the audio in real-time. Low frequencies (bass) are on the left, high frequencies (treble) are on the right.

  • Colour gradient: green (low energy) → amber (medium) → red (high energy)
  • Peak dots: the highest level reached recently, which decay slowly

What to Look For

  • A strong left side means lots of bass — good for a sub-heavy sound
  • A flat distribution means a balanced sound
  • Gaps in the middle mean the sound is thin or hollow
  • A highpass filter shows as low frequencies disappearing from the left

18. The Preset System

Built-in Presets

Preset Description
Default – Lowpass The starting point. Oscillators are sine waves, filter is lowpass, some volume LFO and reese. The filter type is locked to lowpass.
Default – All Filters Same sound as the default, but the filter type is not locked — you can freely switch between all 8 filter types.
Randomise All Same starting sound, nothing locked. Use this when you want to randomise everything.

The Lock System

Each parameter and each section has a lock button (🔓/🔒). When a parameter is locked, randomisation won't change it. When a section is locked, none of its parameters will be randomised.

Use locks to protect the parts of a sound you like while freely experimenting with the rest.

Saving Your Own Presets

  1. Dial in your sound
  2. Click Save in the sidebar
  3. Enter a name
  4. Your preset is saved to localStorage (the browser's storage on your device — not on the server)

19. Keyboard & Performance

Computer Keyboard Layout

The computer keyboard maps to piano notes:

Row 2:  Q  W  E  R  T  Y  U  I  O  P
        C# D#    F# G# A# C# D#    F# G#

Row 1:  A  S  D  F  G  H  J  K  L  ;  '
        C  D  E  F  G  A  B  C  D  E  F

Octave Controls

Key Action
+ or = Octave up (max 9)
− Octave down (min 1)
1–9 Jump to that octave directly

Piano

Click or tap the piano keys in the footer. The visible octave depends on the current octave setting. ◄ / ► buttons shift the range.

BPM

Click the BPM label (e.g. "174") to open a dialog and set the tempo. The BPM controls LFO sync rates and is embedded in exported WAV filenames.

Sustain

Holding a key sustains the note indefinitely — the volume envelope holds at the sustain level until you release the key.

20. Exporting Audio

WAV Export

Click the ↓ WAV button to download the current sound as a 24-bit WAV file. The button label shows the last played note name (e.g. "↓ WAV C4").

What Gets Exported

The export renders the synth through a fresh signal chain (not the live playback chain). This means: - The full ADSR envelope plays once - Normalisation and DC removal are applied - The rendered loop length is determined by the envelope's total duration

File Naming

The exported file is named neuro-NoteName.wav (e.g. neuro-C4.wav). The note name comes from the last played note.

21. Quick Tips for Beginners

  1. Start simple: Load "Default – Lowpass" and change one thing at a time. Listen to what each control does before moving on.

  2. Use your ears, not your eyes: The numbers are guidelines — what matters is how it sounds.

  3. The filter is your friend: Most of a bass sound's character comes from the filter. Try sweeping the cutoff while holding a note.

  4. Less distortion is more: A little distortion goes a long way. 0.1–0.3 of Soft Clip adds warmth without turning your bass into noise.

  5. Solo the Clarity bands: Use the Listen buttons to hear what each band is capturing. You might be surprised what frequencies are causing muddiness.

  6. Watch the GR meter: If the compressor is reducing by more than 6–8 dB, you're probably squashing the life out of the sound.

  7. LFO Delay is magic: A 1-second delay on a pitch LFO creates a beautiful vibrato that only kicks in on held notes.

  8. RMS normalisation for consistency: Use RMS mode for exports you want to compare at the same perceived loudness.

  9. Lock what you like: If you dial in a great filter sweep, lock it before you randomise. Otherwise it's gone forever.

  10. Try Randomise All: Load the "Randomise All" preset and see what happens. You might stumble on something amazing — and you can always load the default again.