MIDI Latency and Jitter
Latency is a message arriving late; jitter is each arrival being late by a different amount.
Related
A software instrument feels sluggish, a recording lands behind the beat, or notes drift. The cause is often the chain and the buffer, not the sound engine.
The problem
Latency and jitter are easily confused. The first moves a whole passage late, the second makes every note late by a different amount. One can be compensated, the other only reduced.
Protocol or message
MIDI 1.0 runs at 31,250 bits per second, so one byte takes about 320 microseconds and a three-byte message nearly a millisecond. USB MIDI 1.0 class packets travel in one-millisecond frames, and the driver adds timestamps. Latency comes from buffers, drivers and the audio interface; jitter comes from frame alignment and scheduling. Clock jitter makes a follower drift.
Settings and practice
Measure loopback delay before changing the buffer. Use direct monitoring or delay compensation while recording. Do not crush the buffer until it clicks. Put the slowest device last in a chain. Keep one clock master.
What to listen for
A constant offset sounds like dragging; jitter sounds like an unsteady drummer. Bass and kick reveal it first, where a few milliseconds already feel loose.
Common misunderstandings
Latency is not the sound source's fault. A smaller buffer is not always better. A MIDI timestamp is not an audio sample position.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Sources
- MIDI 1.0 串行速率与 USB MIDI 类帧长的公开定义，依规范核查，未抄文本
- 本库文件的音符落点统计，由本地 SMF 解析脚本核对，数值随文件而定
Used for fact-checking only; all prose is original.