Dolby Laboratories DP564 - Manual (Page 49)

DP564 Multichannel Audio Decoder Listening Room Calibration
5-5
To enter the Pro Logic delay setting:
1. On the
Monitor Configuration
menu, select
Speaker Delays
,
then press
Enter
.
2. Select
Pro Logic
and press
Enter
to go to the
Pro Logic Delay
menu.
3. Use the ▲▼ buttons to change the setting to match the value you calculated,
then press
Enter
.
5.3 Calibration
Prior to mixing in a multichannel environment, the monitoring system must be
calibrated to establish a balance between all channels and to ensure that all speakers
play back at the correct level relative to the listening reference position.
There are three options to adjust monitor system playback levels:
• Amplifier gain trim controls
• Mixer’s group outputs (one for each of the L, C, R, Ls, Rs, and SW channels)
• Decoder output level trim controls
The best option is to use your amplifier gain controls to set proper playback levels.
This allows you to maintain optimum signal-to-noise performance from the decoder
and console.
When adjusting playback levels via a console’s group outputs, pink noise readings
depend on the type of console meter used to set reference level (and, strictly speaking,
on the bandwidth of the pink noise signal). In film practice, pink noise level is read
with a true VU meter, or a meter display with a VU characteristic. If reference level is
specified as “0 VU,” where “0 VU” corresponds to –20 dBFS for a digital recording
medium, then pink noise should be set to 0 VU on the console meter, and the sound
pressure level (SPL) set accordingly.
Note: Many modern consoles have peak-reading meters or meter displays. Pink
noise that reads at reference level using a true VU meter will read from
8–12 dB higher on a peak-reading meter or meter display. If your console has
switchable meter characteristics, be sure to select VU mode before setting
pink noise levels.
To properly calibrate speaker levels, use an SPL meter. A suitable and relatively
inexpensive meter is available from Radio Shack (Tandy Electronics outside of North
America). Relative level between channels is more important than absolute level, so
the accuracy of this meter is sufficient for channel balancing.
What is most important is that all of the main channels are set to the same SPL—the
absolute level is secondary to this. However, as a guide, here are some examples of
conventional level settings.