Latência por buffer

Audio buffer latency: from samples to milliseconds

To get audio I/O latency from the buffer size, use latency_ms = buffer_samples / fs · 1000. A 512-sample buffer at 44.1 kHz comes out to ~11.6 ms. Run the same buffer at 48 kHz and it drops to ~10.7 ms, and a tighter 128-sample buffer at 48 kHz gets you down to ~2.7 ms. As a rough guide, anything under 10 ms feels great for live performance, under 20 ms is fine for tracking, and once you go over 30 ms the delay starts to show up in your monitoring and can trip up a singer or instrumentalist. Keep in mind that round-trip latency stacks the input and output buffers on top of the driver overhead, so the real number usually runs two to three times this single-buffer value. And the audio driver pulls its weight here too: ASIO on Windows, CoreAudio on macOS, JACK or PipeWire on Linux can matter as much as the buffer setting itself.

Applications: music production and live recording

Producers in Logic, Ableton Live, FL Studio and Pro Tools tend to shrink the buffer while tracking, since the low latency keeps things feeling responsive, then bump it back up for mixing so each cycle has more CPU to spare for plugins. Live engineers chase low latency for in-ear monitors. When someone is editing with virtual instruments and CPU-heavy plugins and isn't playing live, a larger buffer is no problem. With ASIO drivers and a dedicated USB audio interface, hitting 5 ms round-trip is fairly routine.

FAQ

Why does smaller buffer cause crackles? Each block has to be ready before the next one comes due, and a smaller buffer leaves the CPU less time to get there. If a plugin runs long, the audio glitches. That's a buffer underrun.

Is round-trip latency just double the buffer? More or less. You're stacking the input and output buffers and adding a few samples of driver overhead on top, which often works out to 2.5–3× the single-buffer figure.

ASIO vs WDM/WASAPI? ASIO skips the Windows mixer and talks to the hardware directly, which is how it gets under 5 ms. Standard WDM/WASAPI tends to sit around 20–40 ms.