Change parameters to build an exact command. Your agent runs it with sb and gets the WAV.
Command
$ sb get 4M8SGZA790@1 --preset valley -o distant-train-horn-chord.wav
How it's made
Source
compressed air drives five horn diaphragms; seven additive harmonics per horn model the buzz. Filtered pink turbulence adds breath below the pitched body, without a valve click at this distance.
Body
fundamentals at 1, 1.189, 1.498, 1.782 and 2 times 247 Hz form an uneven locomotive chord. Strong second and third harmonics give brass projection; air absorption rolls off above 1.3–3.2 kHz.
Envelope
pressure builds over 130–210 ms, sustains for 0.85–1.65 s, then releases over 240 ms. Each diaphragm speaks a few milliseconds apart; pitch settles upward by 0.9% as pressure builds.
Modulation
common slow pressure wander and independent 0.2% pitch drift keep the chord alive.
Space
a compact direct image, offset hillside reflections at 130/210 ms and a four-delay diffuse reverb. The last 0.6 s progressively fades the remaining reflections to silence within 3.3 s.
Variation
seeded tuning offsets of 0.15% and starting phases; presets vary register, blast length, air absorption and reflected energy for freight, valley, short warning and night-distance uses.
Parameters
Parameter
Range
Default
Unit
Controls
pitch
195 – 300
247
Hz
Lowest horn
sustain
0.85 – 1.65
1.45
s
Blast sustain
distance
0 – 1
0.65
—
Distance
echo
0 – 1
0.5
—
Landscape reflections
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.