Risers
Accelerating heartbeat
Risers · 2026-10-06
Related guide: Horror and Tension Sound Effects: Heartbeats, Braams and Silence
Claude Opus 5.5
Mid tempoDarkEnergetic
New
Space
Prompt
A 12-second tension builder with no pitch centre, all in the low body. A heartbeat starts on frame 0 at 60 BPM: each beat is a "lub-dub" pair of mono sub thumps (a pitch-dropping sine with a muffled knock; the "dub" is shorter and a little higher). The heart speeds up smoothly to about 150 BPM, and its thumps grow harder and closer together. Above it, a faint high tinnitus ring fades in and slowly beats between the ears. Underneath, a breath-like noise swell grows from slow, deep breaths into fast, shallow panting. On frame 330 (11.0 s), mid-beat, everything flatlines: the whole bus cuts to dead silence through a 2 ms fade that ends on the cue. After a held silence, one distant, soft, muffled thud sounds in a small dark room and dies away. Only the mono heart thumps sit below 120 Hz.
Metrics
- Integrated LUFS
- -14.1 LUFS
- True peak
- -6.1 dBTP
- Length
- 12s · 576,000 samples @ 48000 Hz
- Target master
- -14 LUFS · peak ≤ -1 dBTP
- Checks
- Passed
Spectrogram
Generated code
Loading…Timing & cues
60 BPM · 30 fps · seed 1133011
- Frame 0: first beat
- Frame 330: flatline cut
Stems: mono lub-dub sub thumps (pitch-dropping sines, soft tanh, muffled 70-320 Hz knock) on a smooth 60->150 BPM tempo curve with shrinking lub-dub gap; faint 7.35/7.357 kHz tinnitus ring (7 Hz inter-ear beating); stereo breath noise (bright inhale / low exhale bands) whose cycles speed up and swell. Pre-cut bus is filtered, limited and DC-blocked first, then cut by a 2 ms fade ending on frame 330 (mid-beat, the dub never comes); 0.42 s of silence, then one low-passed distant thud in a small dark room. DC trimmed with a sub-audio ramped constant; no flags.
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