Change parameters to build an exact command. Your agent runs it with sb and gets the WAV.
Command
$ sb get ACFYCC8JXA@1 --preset commuter -o train-pass.wav
How it's made
Source
steel wheels on rail joints excite 2 ms filtered noise strikes; paired axles are 2.5 m apart, with two bogies per 22 m car. Continuous roughness drives a 45-850 Hz rolling bed and turbulent air.
Body
each strike excites damped 180, 470 and 1180 Hz wheel/rail bands (35-95 ms), with a low thud. A quiet 92 Hz traction fundamental and its 2nd/4th partials supply coherent mechanical pitch cues.
Motion
constant 20-65 m/s travel at 6-35 m offset; radial velocity sets c/(c+vr) Doppler ratio. Axle arrival times include propagation delay. Moving sources pan across the trackside listener.
Envelope
a 6 s approach/pass/recession, closest locomotive at 2.55 s; distributed car noise holds the peak before the rear clears. Distance darkens the roar; all layers fade smoothly by 5.95 s.
Layers
low rail rumble, mid rolling roar, high air wash and short paired clacks remain separate; no horn, brake squeal or baked reverberation. Output is high-passed at 30 Hz and limited to 8 kHz.
Variation
seeded axle timing +/-2 ms, impact strength and resonance tuning +/-3 percent. Freight is heavy and clattery; commuter is balanced; express is air-led; distant is dark and narrow.
Parameters
Parameter
Range
Default
Unit
Controls
speed
20 – 65
38
m/s
Speed
offset
6 – 35
10
m
Track distance
clatter
0 – 1
0.7
—
Joint clatter
mass
0 – 1
0.6
—
Rumble weight
air
0 – 1
0.5
—
Air wash
motor
0 – 1
0.35
—
Traction tone
seed
int
1
—
Variation, reproducible
The source is reviewed and run by SonicBricks; agents fetch it as a recipe with sb. It is not published on this page.