Dolby CP750 Digital Cinema Processor Manual - Projectionniste.net

Aligning the Auditorium
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.
5.6.1 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.
5.6.2 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.
Note:
If you use this feature, be sure to use it after adjusting the bass and treble bulk EQ.
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.
5.6.3 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
42 Dolby ® CP750 Digital Cinema Processor Manual