Latency Budget
Input, processing and output buffers add up to a round-trip delay that decides whether playing feels immediate.
Related
The question
From key press to speaker, sound passes input buffering, plug-in processing and output buffering. They add up to a round-trip delay; past ten or twenty milliseconds, playing feels behind the hand.
How it works
Buffers work in blocks; block size divided by sample rate gives one block's time. At 48 kHz, 256 samples last about 5.3 ms, so a round trip is about 10.7 ms, while converter and driver overhead push it to 15 or 20 ms. Acoustic instruments carry their own delay, and each metre of monitoring distance adds about 2.9 ms. Latency is a budget.
Settings and practice
Drop the buffer to 64 or 128 samples when tracking and relax to 256 or 512 when mixing. Use hardware direct monitoring to bypass the software path. Measure the real round trip rather than trusting a settings panel, then re-measure after changing interfaces.
What to listen for
On a reel, hear how ornaments sit under the fingers. In a 138 BPM funk loop, count the sixteenth-note spacing. Too much delay makes a player rush, which sounds hurried.
Common misconceptions
Smaller buffers are not always better, because too small causes dropouts. Latency affects mixing too, in fader and knob response. A USB microphone is not necessarily slow; the driver and buffer matter. Delay compensation aligns recorded material but does not remove monitoring delay.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Sources
- 缓冲、采样率与往返延迟的换算，依音频接口厂商公开资料核查，未抄文本
- 监听距离与声速的关系，依声学通识核查，未抄文本
Used for fact-checking only; all prose is original.