Bass Design

Bass is weight. Bass is darkness. Bass is the thing that makes people move without thinking about it.

In a club, you don’t just hear bass — you feel it in your ribs, in your teeth, in your bones. That physical impact is what we’re building here.

The Layering Philosophy

A powerful bass isn’t one sound — it’s several sounds working together:

1. Sub layer — Pure low frequency (sine wave), felt more than heard
2. Mid layer — Character and grit (saw, square, TB303)
3. Top layer (optional) — Attack and presence

define :bass do |n, v=1, c=80|
  # Mid layer - character
  use_synth :tb303
  play n, amp: 0.8*v, attack: 0.01, decay: 0.2, 
       sustain: 0.1, release: 0.15, cutoff: c, res: 0.3
  
  # Sub layer - weight
  use_synth :sine
  play n-12, amp: 1.1*v, attack: 0.01, sustain: 0.25, release: 0.2
end

The sub plays one octave lower (n-12) and uses a pure sine wave. The TB303 provides the gritty character.

The TB303 Sound

The Roland TB-303 bass synthesizer defined acid house and remains central to electronic music. Sonic Pi’s :tb303 synth emulates it:

use_synth :tb303
play :e2,
  amp: 0.8,
  attack: 0.01,
  decay: 0.2,
  sustain: 0.1,
  release: 0.15,
  cutoff: 80,      # Filter frequency - higher = brighter
  res: 0.3,        # Resonance - higher = more "squelchy"
  wave: 0          # 0 = saw, 1 = square

Key Parameters

cutoff (30-130): Controls brightness

• 60-70: Dark, subby
• 75-85: Balanced, present
• 90+: Aggressive, cutting

res (0-1): Resonance adds character

• 0.2-0.3: Subtle color
• 0.4-0.5: Classic acid sound
• 0.6+: Screaming, use carefully

wave: Waveform shape

• 0 (saw): Brighter, more harmonics
• 1 (square): Hollow, more fundamental

Alternative Bass Synths

Prophet — Warm and Musical

use_synth :prophet
play :d2,
  amp: 0.6,
  attack: 0.03,
  decay: 0.25,
  sustain: 0.15,
  release: 0.2,
  cutoff: 75,
  res: 0.2

Used in: Chrome Cathedral, Terminal Velocity

Dsaw — Aggressive and Wide

use_synth :dsaw
play :d2,
  amp: 0.5,
  attack: 0.01,
  decay: 0.2,
  release: 0.15,
  cutoff: 80,
  detune: 0.2    # Spread between oscillators

The detune parameter creates width. Higher values = wider, more aggressive.

Bass Layering Examples

Track 1: System Override

define :bass do |n, v=1, c=80|
  use_synth :dsaw
  play n, amp: 0.6*v, attack: 0.01, decay: 0.15, 
       sustain: 0.1, release: 0.15, cutoff: c, detune: 0.15
  
  use_synth :tb303
  play n, amp: 0.5*v, attack: 0, decay: 0.2, 
       sustain: 0, release: 0.1, cutoff: c-10, res: 0.4, wave: 1
  
  use_synth :sine
  play n-12, amp: 1.2*v, attack: 0.02, sustain: 0.3, release: 0.2
end

Three layers:

1. Dsaw — Width and aggression
2. TB303 (square wave) — Grit and character
3. Sine — Sub foundation

Track 2: Nerve Damage

define :grind do |n, v=1, c=75|
  use_synth :tb303
  play n, amp: 0.8*v, attack: 0.01, decay: 0.2, 
       sustain: 0.1, release: 0.15, cutoff: c, res: 0.3, wave: 0
  
  use_synth :sine
  play n-12, amp: 1.1*v, attack: 0.01, sustain: 0.25, release: 0.15
end

Simpler layering, but with higher resonance for that “grinding” character.

Writing Bass Patterns

The One-Bar Pattern

Most tracks use 4-beat bass patterns:

define :bassline do |v=1, c=80|
  bass :d2, v, c; sleep 0.75
  bass :d2, v*0.7, c-10; sleep 0.25
  bass :f2, v*0.9, c; sleep 0.5
  bass :d2, v*0.8, c; sleep 0.5
  bass :a2, v, c+5; sleep 0.5
  bass :d2, v, c; sleep 1.5
end

Notice:

• Velocity variation (v*0.7, v*0.8) — Creates groove
• Cutoff variation (c-10, c+5) — Adds movement
• Rhythmic variety — Mix of 0.5, 0.75, 1.5 beat notes

Creating Movement

Use multiple bassline variations:

define :bass1 do |v=1, c=75|
  bass :g1,v,c; sleep 0.5
  bass :g1,v*0.5,c-5; sleep 0.5
  bass :bb1,v*0.8,c; sleep 0.5
  bass :g1,v*0.9,c; sleep 0.5
  bass :f1,v*0.7,c; sleep 0.5
  bass :g1,v,c+5; sleep 0.5
  bass :d2,v*0.8,c; sleep 0.5
  bass :g1,v,c; sleep 0.5
end

define :bass2 do |v=1, c=75|
  bass :g1,v,c; sleep 0.75
  bass :bb1,v*0.85,c; sleep 0.25
  bass :c2,v*0.9,c; sleep 0.5
  bass :d2,v,c+8; sleep 0.5
  bass :eb2,v*0.95,c+5; sleep 0.5
  bass :d2,v*0.8,c; sleep 0.5
  bass :bb1,v*0.7,c; sleep 0.5
  bass :g1,v,c; sleep 0.5
end

Then alternate them:

4.times do
  bass1 1, 80
  bass2 1, 80
end

Bass Notes by Key

Each track uses a specific key. Here are the root notes:

Filter Automation

Make bass evolve over time:

in_thread do
  with_fx :lpf, cutoff: 60, cutoff_slide: 32 do |fx|
    control fx, cutoff: 90  # Slide from 60 to 90 over 32 beats
    8.times do
      bassline 1, 70
    end
  end
end

This creates a “filter opening” effect — the bass gets brighter over time, building energy.

Tips for Heavy Bass

1. Don’t overcomplicate — Two layers often beat four
2. Keep sub clean — No effects on the sine layer
3. Use cutoff variation — Even ±5 adds life
4. Leave space — Not every beat needs bass
5. Match the kick — Bass and kick should complement, not fight

Next: Leads and Melodies — how to write the hooks that define each track.