glossary
VU meters are slow on purpose. They show musical level instead of chasing every transient.
VU stands for Volume Unit. A VU meter responds slowly compared with a digital peak meter, so it shows a smoothed sense of level over time.
That makes it useful for judging body, consistency, and analog-style gain staging, but it will not catch every fast peak.
VU metering helps set vocal, bass, drum bus, and mix bus levels without reacting to every transient. It is also common for calibrating plugins modeled on analog gear.
A source that looks jumpy on a peak meter can sit clearly on a VU meter once its average level is stable.
Use VU to understand average level and tone-shaping input drive. Use peak or true peak meters to protect digital headroom.
If a VU meter says the level is right but your peak meter is overloaded, fix the transient or trim the stage before the next processor.