442/442N User Guide and Technical Information
14
v. 5.07
Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
Metering
The 442 features a large 40-segment (20 per channel) LED output meter. The meter uses energy-
effi cient GaN LED's, which can be viewed in full sunlight. The 442 output meter is unaffected by shock,
temperature, or humidity extremes. The microcontroller-based output meter provides a selection of
ballistics and lighting intensities.
Meter Ballistics
The output meter can be set to display any of four types of meter ballistics - VU, Peak, a composite
of VU and Peak, and a composite of VU with Peak hold. Change the meter ballistics at anytime by
Pressing the PK/VU button.
See the Setup Menu for selections.
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 great visual indications of how loud a signal will be.
However, VU meters provide poor information of actual signal peaks.
In VU mode, the front panel meter labeling is in volume units. VU meters are always referenced to an
actual signal level in dBu, the 442 VU meter is referenced with 0 VU corresponding to 0 dBu at the Line-
Level outputs. If needed, the reference level can be changed in the Setup Menu to +4 or +8 dBu.
Peak
Peak-reading ballistics correspond to actual signal peaks, but don't necessarily correspond to perceived
signal loudness. The peak meter has an instantaneous attack and a slow decay to allow the user to
visually monitor peak activity. Peak metering is useful when interconnecting to audio inputs on digital
equipment. In the digital realm, signal overload can cause immediate distortion.
The peak meters front panel markings are calibrated in peak dBu level at the Line-Level outputs.
VU/Peak -
The 442 can simultaneously display VU and Peak level information. In this mode the perceived
loudness (VU) is displayed on a bar graph, and the Peak signal on a dot above the VU. With this
combination the user gets the best of both VU and Peak metering by seeing the "loudness" of the signal
while observing peaks at the same time.
VU/Peak Hold
(fi rmware v. 3+ only) Similar to VU/Peak mode, this mode holds the peak level indication for several
seconds before releasing. Peak Hold indicators are useful for metering in applications when an overload
condition is unacceptable.
Ballistics Lock
(fi rmware v. 3+ only) Lock the selected meter ballistics setting by simultaneously pressing the Battery
Check and Meter Brightness buttons. This setting is saved on power down.
Summary of Contents for 442
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