Dolby
®
Model CP650 Installation Manual
B-Chain Alignment
4-17
Crossover Levels
>Channel: Left Hi
>Channel: Left Hi
>Channel: Left Hi
>Channel: Left Hi
Level: 70
4.7 Room
Equalization
Room equalization is performed using the real-time analyzer (RTA) circuit built into
the CP650 along with an oscilloscope for RTA display. The adjustments for all output
channels involves two steps: coarse, or “bulk,” adjustment using bass and treble
controls, and fine adjustment, using a 27-band equalizer. Subwoofer channel
equalization involves setting the frequency, “Q,” and level of “cut,” using a single-
band parametric equalizer circuit.
If your CP650 is equipped with an optional Cat. No. 791 Crossover Board, there are
additional steps to perform before setting room equalization. See Section 4.7.1 below.
The RTA screen on the scope displays a standard (ISO 2969) response curve. The
ideal setting is reached when the room response readings fall on (or very close to) this
standard curve.
Note
: If pink noise is not being generated, this indicates that the status of the digital
input has changed. If you are using the digital input on the CP650, either disconnect
or power down the device attached the digital input during equalization. A change in
the digital input bitstream will cause the CP650 to mute the pink noise.
4.7.1
Crossover Level Adjustment (for CP650s with Cat. No. 791)
If your CP650 is equipped with a Cat. No. 791 Crossover Board, perform the steps
below before adjusting the bulk treble and bass settings in the next section. In order to
properly set the levels of the various bands (low and high for 2-Way, or low, mid, and
high for 3-Way systems), you must first adjust the levels of all bands to be
approximately equal. By performing this adjustment first, the final amount of
equalization required to match the standard response curve will be less.
menu
OK
From the main format screen, press the left
menu button multiple times to display the
Crossover Levels
screen.
Rotate the front-panel knob to select the
Left
channel
high
-frequency output.
Note:
With the crossover mode set to 2-Way or 3-Way,
each output (low, mid, and high) will affect the RTA
display in the band set by the crossover corner
frequency settings. Each crossover output level (mid
and high) should be adjusted separately from the main
level control in order to match the low-frequency
output level.
