Dolby Laboratories CP750, Руководство пользователя

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50 Dolby
®
CP750 Digital Cinema Processor Manual
Aligning the Auditorium
6.6.1 Setting Bulk EQ
This process simultaneously adjusts all bass or all treble frequencies. It is important to
adjust both of these prior to adjusting the individual one ‐ third octave bands.
Bass Level
The Bass level on the Channel Tune tab is adjustable from –6 to +6 dB in 0.2 dB steps. Using
the slider, approximate the reference curve as closely as possible.
Treble Level
The Treble level is adjustable from –10 to +10 dB in 0.2 dB steps. Using the slider,
approximate the reference curve as closely as possible.
Treble Frequency Corner
The Treble corner frequency can be set to 1, 2, 3, or 4 kHz, and applies to all channels.
Choose the setting that matches the reference curve most closely.
6.6.2 Using EQ Assist
The EQ Assist feature automatically adjusts the frequency response to the x ‐ curve. Use this
feature with care since it adjusts adjacent bands as necessary (even to extremes) to achieve
the exact x ‐ curve. The EQ Assist feature does not adjust to room anomalies as a human
operator can, avoiding overcompensation in any frequency bands.
To prevent overcompensation for possible speaker problems, the 20, 25, 30, 40, 50, and
63 Hz, as well as the 12.5 and16 kHz, bands are not automatically adjusted. You must adjust
these bands manually.
6.6.3 Making Fine Adjustments to Individual Bands
Observe adjacent band effects when adjusting individual frequencies. Be aware of
frequency bands that are very different from neighboring bands, and use caution so as not
to overcompensate. (Major differences could be the result of a room node at the particular
microphone location.) Adjust each frequency band as necessary to achieve a smooth EQ
with results nearing the x ‐ curve overlay. The goal is to achieve (or come close to) the
x ‐ curve without overcompensating. Remember that the SMPTE tolerance is ±3 dB,
although closer results are often easily achieved.
6.6.4 Adjusting LFE Channel EQ
Begin with zero cut and observe the worst peak within the spectrum. Adjust the Center
slider until the frequency matches the peak, and then adjust the Cut to flatten that region.
Adjust the Q (width) and Cut , until the smoothest response is achieved.
Note: If you use this feature, be sure to use it after adjusting the bass and treble bulk EQ.