Dolby Laboratories CP750, Руководство пользователя

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Room Equalization
Dolby
®
CP750 Digital Cinema Processor Manual 49
Figure 6 ‐ 4
Figure 6-4 Channel Tune Tab Showing LFE EQ
Initial subwoofer level setting uses a blue reference line displayed on the LFE Channel
Tune tab, established from the Center channel pink ‐ noise level. Using the Channel Level
slider, adjust the level, moving the average subwoofer RTA display to match the reference
line on the screen as closely as possible. Final subwoofer level adjustments for both digital
and Dolby ® Pro Logic ® signal paths are carried out later, after the room is equalized.
6.6 Room Equalization
Room equalization is performed using the RTA built into the CP750. The desired result is
a frequency response that closely matches the “x ‐ curve” overlay (SMPTE 202M ‐ 1998).
Results achieved within ±3 dB of the x ‐ curve are considered within tolerance of the
specification. Small diameter, pressure calibrated microphones are preferred for accuracy
over large diameter types. Use of a microphone multiplexer will accommodate spatial
averaging of different positions within the room, which is recommended for best results.
Follow this sequence:
1. Perform coarse adjustments of each channel using the Bulk EQ Bass and Treble
sliders.
2. Perform fine adjustments of each band using the 27 ‐ band one ‐ third ‐ octave equalizer.
3. Perform LFE channel equalization by setting the frequency, Q (width), and level of
cut, using the single ‐ band parametric equalizer.