Proceed PDSD - Manual (Page 42)

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3 MAKE A NOTE OF THESE SETTINGS UNDER “YOUR SYSTEM SETTINGS” IN
THE BACK OF THIS MANUAL
Having these settings handy will prove helpful should anyone ever tamper
with your careful calibrations. Of course, you should re-calibrate the system
if you move the speakers or listening position significantly.
4 SAVE ALL YOUR CHANGES AND RETURN TO THE SET SPEAKERS MENU
Once you have each channel adjusted properly, press
menu to return to the
set speakers menu so you can continue the initial setup of your system.
set levels The PAV/PDSD incorporates level controls for each channel. These allow you to
compensate for differences in amplifier and speaker sensitivities, and for place-
ment variations in different rooms. These adjustments are essential for re-
producing proper soundstaging and image localization.
Fortunately, they
are normally a onetime adjustment during setup, and only need to be revisited if
amplifiers or speakers change.
The simplest and best way to adjust the output level controls is by using an
Sound Pressure Level (SPL) meter and the internal test tone generator. The goal is
to set the volume at the primary listening position to read 75 dB SPL (C-weight-
ing, slow mode) from each speaker in sequence, using the individual output level
controls. An appropriate SPL meter can be purchased from Radio Shack for about
$30 (tip: buy the analog meter rather than the digital one). You should point the
meter at the ceiling so as to avoid inadvertently favoring one speaker over an-
other.
Note: If the test tones in Chapters 8-11 of the Lucasfilm WOW! test
disc are used, the meter should read 85 dB SPL, since these
tones are recorded at a level 10 dB higher than those
generated by the internal generator. Also, if external analog
test tones such as these are used, you must also be certain
that the analog input level calibration has been done
accurately prior to calibrating the output levels—see steps 4-
5 of “defining multiple audio connections.”
In the absence of an SPL meter, it is possible (though less desirable) to set the
output level controls by ear. Use the built-in pink noise generator in the PDSD to
adjust all volumes to sound the same as they cycle around the various speakers.
(This signal is bandwidth-limited pink noise to limit the problem of timbre shifts
influencing the setting of levels.) The system will then be reasonably well bal-
anced, although of course it is not “calibrated.”
1 ENTER THE SET LEVELS MENU
Select
set levels in the set speakers menu and press enter . You will then
see a screen which should look something like the following: