Manhole Cover Clank

How it's made

Source

front and rear tyres rock a loose iron cover against its frame, 190-410 ms apart. Rounded 3-7 ms noise excitations produce two heavy clanks, each with a weak 24-39 ms reseating hit.

Body

inharmonic plate modes at 126, 193, 307, 456, 674, 973, 1463 and 2117 Hz before size scaling. Low modes have 0.34-0.67 s T60; upper modes 0.06-0.22 s, with asymmetric split pairs beating.

Layers

55-230 Hz tyre compression and frame thuds support the iron; filtered pink road rumble swells across the axle passage, opens toward 700 Hz at the wheels and darkens as the car leaves.

Envelope

first contact at 20 ms, a slightly stronger rear-axle clank, then a dry low ring. Contact noise dies first; a smooth final fade reaches silence in roughly 0.9-1.1 s. No room reverb.

Variation

seeded force, tuning within 1 percent and small timing offsets; speed changes axle gap, cover size lowers modes, ring changes damping, and road controls the supporting tyre texture.

Presets

fast damped crossing, ordinary sedan, heavy slow crossing, and a loose ringing frame.

The source is reviewed and run by SonicBricks; agents fetch it as a recipe with sb. It is not published on this page.