Meter Ballistics; Peak + Vu; Peak Only; Peak Hold - Sound Devices 664 User Manual And Technical Information

664 User Guide and Technical Information

Meter Ballistics

Audio meter "ballistics" is the manner in which a visual meter responds to audio signal levels. The
ballistics of all 664 meters is set globally from Setup Menu option SYSTEM > Meter Ballistics.
VU
VU (volume units) meter ballistics correspond closely to how the human ear perceives loudness. This
provides a good visual indication of how loud a signal will be. In VU mode, the attack and decay of
the meter signal is 300 mS. VU meters provide good visual indication of how loud a signal will be, but
provide poor information of actual signal peaks.

Peak + VU

The 664 can simultaneously display VU and Peak level information. In this mode the perceived loud-
ness (VU) is displayed as a standard bar, and the Peak signal as a single, independent segment above
the VU.

Peak Only

Peak-reading ballistics (PPM) correspond to actual signal peaks, but don't necessarily correspond to
perceived signal loudness. Peak meters have an instantaneous attack and a slow decay to allow visual
monitoring of peak activity. Peak metering is useful when interconnecting to audio inputs on digital
equipment. In the digital realm, signal overload can cause immediate distortion.

Peak Hold

When Peak Metering is enabled (Peak Only or Peak + VU), peak hold displays the last high-
est peak value on the meter as a separate, individual meter segment. By default this meter seg-
ment will remain visible for 1 second. This time can be adjusted from Setup Menu option
SYSTEM > Meter Peak Hold Time to 1, 2, 3, 4, or 5 seconds. The Infinity option will display the last
highest peak indefinitely until a higher peak is reached. The Off option will disable peak hold.

Input Activity LED

Each Input has its own Input Activity LED located just above the Input Fader.
The LED illuminates in various colors and intensities to represent the signal
level appearing at its respective input. Green = pre-fade signal activity, yellow
= pre- and post-fader limiter activity, red = pre- and post-fader signal overload
(peaking). Reduce the trim level control if the LEDs continuously illuminate
yellow or red. The Input Activity LED will flash yellow when the Input PFL is
latched. see PFL.
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v . 2 .01 Features and specifications are subject to change . Visit www .sounddevices .com for the latest documentation .
Meter Appearance Track Name Display Style
Off
Left
Left (w/ramp)
Right