Dacs Calibration

SDP-40

The SETUP Menu

LEVEL ADJUST menu. The cursor will automatically scroll through the menu highlighting each output as it is tested. Each output is tested for approximately 4s. It is possible to manually select a speaker just as the unit is about to automatically scroll to the next speaker, causing the unit to send the noise signal to both outputs. If this occurs, reselect the desired speaker.

The calibration noise will pass briefly through the SUB R output when the SUB L/R parameter on the CUSTOM SETUP or SYNTHESIS 7CH SETUP menu is set to MONO, or the SUB RIGHT parameter on the SPEAKER LEVELS ADJUST menu is manually selected during the test.

Before making adjustments, set the SPL meter to “C” weighting and “SLOW” response. Use the up and down MENU arrows to temporarily interrupt automatic scrolling and manually select an output. Press the right MENU arrow to select an output for adjustment, then use the up and down MENU arrows to increase and decrease the level of the selected output in 0.5dB increments within a range of -18 to +12dB. Adjust all output levels to achieve a 75dB reading on the SPL meter from the primary listening position. Press the left MENU arrow to exit the selected output and resume automatic scrolling.

Note:

Speakers that are set to NONE on the CUSTOM SETUP menu cannot be adjusted during the INTERNAL NOISE TEST. These speakers can be adjusted during DACS CALIBRATION, but this is not recommended.

Selecting either INTERNAL NOISE TEST or DACS CALIBRATION accesses the SPEAKER LEVEL ADJUST menu (pictured on the previous page).

DACS CALIBRATION requires an external noise source. In JBL Synthesis systems, this source is the JBL Digital Acoustical Calibration System (DACS®). However, an alternate source such as an audio calibration disc can also be used. As the noise test is conducted, the SDP-40 loads the DOLBY Pro Logic II, Dolby Digital, or dts(-ES) utilizing the signal from the DACS® calibration system or audio calibration disc.

For example, if an analog or PCM input type is coming into the unit when DACS CALIBRATION is conducted, the unit will activate the DOLBY Pro Logic II listening mode. If a Dolby Digital input type is coming in, the unit will activate the DOLBY DIGITAL listening mode. And if a dts(-ES) input type is coming in, the unit will acti- vate the dts(-ES) listening mode. When DACS CALIBRATION is selected, these listening modes will retain their factory-default settings. The unit will temporarily disregard customized listening mode settings.

For system optimization using DACS® and a JBL Synthesis Digital Equalizer, connect the left and right RCA outputs of the DACS® signal generator (EVP-1) to the #1 analog input (which is active in the TAPE input) and set the front panel volume level to 0dB. This will provide the correct signal path and reference output level.

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