Dolby Laboratories CP750, Руководство пользователя

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Initial Output-Level Adjustment
Dolby
®
CP750 Digital Cinema Processor Manual 47
4. With a sound pressure level meter, measure the noise level in the room. Hold the
sound pressure level meter near the location of mic 1, discussed in Section 6.2 .
5. Enter the measured value into the Measured Value field.
6. Wait while the system automatically calibrates to the room reading.
The calibration is retained in CP750 memory and can be used in future alignments.
However, it is advisable to recalibrate the system when rearranging microphones because
the sound pressure level varies slightly with microphone placement.
6.5 Initial Output-Level Adjustment
Next, adjust each channel slider to make sure the pink noise is audible and to achieve a
reasonable sound pressure level in the auditorium. It is not necessary to set exact levels
because the levels will change slightly during equalization. Exact output level adjustment
is performed after equalization.
6.5.1 Setting Main Channel Levels
When the CP750 is first installed, you must repeat these steps for each channel. Values are
adjusted on the Channel Tune tab after a channel is chosen. Figure 6 ‐ 3 shows an example
with the Center channel selected.
1. Click a channel radio button to make it active and lock pink noise to it.
2. Check the level indicated underneath the Channel Level slider, and move it up or
down until the measured level reads 85 dB.
3. Repeat steps 1 and 2 for the R and L channels, setting the Channel Level to 85 dB.
4. Repeat steps 1 and 2 for the Rs , Ls , Bsr , and Bsl channels, setting each to read 82 dB.
Note: For this and all other adjustments using sliders, use the slider to get close to the
optimal value. Use the up and down arrow keys to make fine adjustments.