Metering

Metering

The 744T features a 76 LED (4 x 19) output meter. The DSP-controlled output meter provides a selection of ballistics and lighting intensities. In addition, peak indicators on input channels show clipping activity.

Output Meter

0 dBFS track LEDs are programmable as peak LEDs

(0 dBFS to −20 dBFS)

The meter uses energy efficient LEDs which are viewable in full sunlight. The 744T output meter is unaffected by shock or extremes in temperature and humidity. Meter ballistics are setup menu selectable among VU, Peak, Peak-Hold, VU + Peak and VU + PeakHold.

The meter uses a non-linear metering scale which increases meter resolution in the most important part of the scale. From −50 to −40 dBFS, each LED segment equals approximately 10 dB. From −40 to −12 dBFS, each segment equals 2 dB. From −12 to 0 dBFS each segment equals 4 dB.

Meter Ballistics

The output meter can be set to display any of five types of meter ballistics: VU, Peak, Peak-hold, a combination of VU and Peak, and a combination of VU with Peak-hold. The meter ballistics are selected in the setup menu.

VU - (Volume Units)

Ballistics correspond closely to how the human ear perceives loudness and 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. While giving a very good visual indication of perceived loudness, VU meters gives poor information on actual signal peaks and are virtually useless for tracking to the 744T. In VU mode, the front panel meter labeling is in volume units.

Peak

Peak-reading ballistics correspond to actual signal maximums, but don’t necessarily correspond to perceived signal loudness. A peak meter has a near-instantaneous attack to display maximum signal amplitude and a slow decay to allow the user to see them. Peak metering is essential for digital re- cording, since signal overload can cause immediate distortion. The peak meters front panel markings are calibrated in dBFS, decibels relative to full scale digital signal.

Peak Hold

Essentially the same as Peak metering where the peak level indication will hold for the peak level indication for several seconds. Peak-hold indicators are useful for metering in applications when an overload condition is unacceptable.

Peak/VU

The meter 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

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