SPL (sound pressure level) / 聲壓級 — theatre and live events glossary

showstack / glossary / spl

SPL (sound pressure level) 聲壓級

audio

How loud it is at a given point, in decibels relative to 20 micropascals. Always qualified: a frequency weighting (A, C or Z), a time weighting (fast, slow) or an averaging period (LAeq over 15 minutes, an hour, the show).

中文

某一位置的音量大小，以相對於 20 微帕的分貝值表示。必須加上限定條件：頻率權重（A、C 或 Z）、時間權重（快、慢）或平均時距（15 分鐘、一小時或整場的 LAeq）。

Regional usage

Where	Term	Note
UK / US	SPL
HK / TW	聲壓級 / SPL / 音壓

Easy to get wrong

A venue limit of "100 dB" means nothing until you know the weighting, the averaging time and the measurement position. 100 dBA slow at FOH and 100 dBC peak at the barrier are wildly different limits.

Next to this

Gain before feedback (GBF)回授前增益How much a microphone can be turned up before the system starts to ring, usually talked about in dB of headro…

Sources

IEC 61672-1 sound level meters — IEC primary
Theatrecrafts glossary of technical theatre terms — Theatrecrafts / ABTT heritage primary

Understand the mechanism

Measuring and aligning sound Numbers that stand for signals

Something wrong, or missing?

Every entry here is maintained by people who run shows.

Edit this entry on GitHub — one file, editable in your browser, and your handle goes on it permanently.