JBL Synthesis
System
Configuration
26
The EXTERNAL NOISE TEST loads the Pro Logic, 5.1 Dolby or DTS
Music effect and uses the signal from the currently selected input for
calibration.
Once a test source is selected, a sub-menu showing each output level
is displayed. Use the
▲
and
▼
buttons to highlight an output for
adjustment. Press SELECT to stop the cycling of the noise signal, then
use
▲
and
▼
to adjust the selected output level in precise 0.5dB
increments from -10dB to +10dB.
INTERNAL NOISE TEST
EXTERNAL NOISE TEST
LEFT FRONT
CENTER*
RIGHT FRONT
RIGHT SIDE*
LEFT SIDE*
SUBWOOFER*
RIGHT REAR*
LEFT REAR*
▲
▼
Adjust with or
OUTPUT LEVELS MENU
-10dB to +10dB
*These selections will not be active
if "NONE" is selected in the Speaker
Configuration menu.
Using a Sound Pressure Level Meter such as Radio Shack model
33-2050 or 33-2055, set the weighting to C and the response to Slow.
Adjust the subwoofer output to 80dB. Adjust all other output levels to
achieve 75dB at the listening position.
In the absence of an SPL meter, it is possible to set the output level by
ear. Use the internal noise generator in the SDP-3 to adjust all volumes
to be the same as they cycle around the various speakers. Depending
on timbre variations between your speakers, this may be difficult to
judge — get as close as you can. The system should be reasonably well
balanced, although not actually calibrated for precise playback and
level matching. With the system volume at 0dB, the internal noise
source should be at the same level at which film dialog sounds
comfortable.
Note on External Noise Calibration
When using the external noise calibration, the SDP-3 will load the
factory default effect for the format of the incoming signal. In other
words, if a PCM signal is coming into the SDP-3 when external noise is
engaged, the SDP-3 will load the PRO LOGIC effect with the factory
preset settings. If a Dolby Digital AC-3 signal is coming in, the SDP-3 will
load the 5.1 DOLBY effect with the factory preset settings. If a DTS
signal is coming in, the SDP-3 will load the DTS MUSIC effect with the
factory preset settings.
NOTE: The Volume control is active when utilizing external noise
calibration.
