LED meter on mixer

The two LED VU meter found in the ST-UMX3 is a good example of how this simple level indicator can be used in equipment setup. The green LED is an indication of average (VU ballistics) audio level. It starts to illuminate when the line level output of the mixer is at -11 dBu. It will reach full intensity when the level is at +4 dBu. The red LED serves as a peak indicator. It will light when output level is +4 dBu. The nominal line level output of the ST-UMX3 is +4 dBu. At this level, the unit maintains 18 dB of headroom. (The red LED is a peak indicator – not a clipping indicator.)