Ping-pong delay (@maru/delays-ping-pong)

Performance

4 measured workloads · Node.js · Apple M4 Pro

Typical processing

1.25 µs

Busier blocks

1.33 µs

Share of the test budget

0.1%

250.5 ms · feedback 0.7 · 96 kHz · 1.333 ms available per block in this test.

Processing cost

Processing time in µs · lower means less work

Select a point to inspect its measurements. Hollow points indicate variable timing. Lines guide the eye; only marked cases were measured.

Retained DSP buffers: 1500.0 KiB
Impulse first arrival: 250.50 ms
Peak output: -13.98 dBFS

Captured energy decay

Remaining energy · dB

Stereo-summed backward squared-energy integration, sampled every 20 ms, normalized to the captured 2 s impulse response. Finite-window curve; no extrapolated RT60 claim.

Measurement details

Retained DSP buffers · 1500.0 KiB: Unique backing-buffer capacity reachable from prepared DSP state, including borrowed rings and retained scratch. Excludes JS objects, scalar fields, harness buffers and transient allocation; zero does not mean zero total memory.
Peak output · -13.98 dBFS: Last 4096 frames of a 0.5 s steady render. Effects receive a 0.2-peak 1 kHz sine; sources generate their declared waveform. No automatic musical-quality verdict.
DC offset · 0.00055: Signed mean over the same steady-render channels and final 4096 frames.
Output RMS · -20.01 dBFS: RMS over all channels of the same steady-render window.
Impulse first arrival · 250.50 ms: First channel sample at or above -120 dBFS after a 0.2 impulse, following 250 ms + 127 frames of silence; 2 s observation. Includes configured delay, phase and any dry path. Not device latency or group delay. No detection is unavailable, not zero.
Energy after 1 second · -9.52 dB: Energy in the second second relative to the captured 2 s response. A long decay may extend beyond the capture.

All measured cases

Sample rate · kHz	Typical · µs	Busier blocks · µs	Test budget used	Observations
48	1.25	1.38	0.1%	—
48	1.25	1.38	0.1%	—
96	1.25	1.38	0.1%	Timing varies
96	1.25	1.33	0.1%	—

Times are per 128-frame audio block. Test budget used divides the p95 time by the block period at that case’s sample rate. Machine and runtime are shared.

Test setup

Node.js · Apple M4 Pro · 48 / 96 kHz · 128 frames per block · 3 repeated tests · Nov 7, 2026

Typical summarizes the middle measured block times. Busier blocks summarizes the time that 95% of blocks completed within in each repeat. These figures measure DSP processing; application scheduling, loading samples and device output require separate checks. Memory and signal probes run separately from the timing loop.

Lean 4 proofs

No proofs published

No Lean 4 proof is mapped to this node.