JBL AVR480 Music Mixer User Manual


 
21
Configuring Global Settings
After the settings described above have
been made for all input sources in your
system, the following settings will
remain in effect independent of the input
selected.
Delay Settings
For the Dolby Digital or Dolby Pro Logic II
modes, you may need to adjust the delay
time setting. Note that the delay time is
not adjustable for any other modes.
Important Note: Once the delay time
is set with any input it will be effective
with all other inputs too. Moreover, the
surround delay time setting must be made
only for either the Dolby Pro Logic II or
the Dolby Digital mode. The other set-
tings will be set automatically.
Due to the different distances between
the listening position for the front chan-
nel speakers and the surround speakers,
the amount of time it takes for sound to
reach your ears from the front or surround
speakers is different. You may compen-
sate for this difference through the use
of the delay settings to adjust the timing
for the specific speaker placement and
acoustic conditions in your listening room
or home theater.
The factory setting (see Surround Mode
Chart page 28) is appropriate for most
rooms, but some installations create an
uncommon distance between the front
and surround speakers that may cause
the arrival of front channel sounds to
become disconnected from surround
channel sounds.
To resynchronize the front, center and
surround channels, follow these steps:
1. Measure the distance from the
listening/viewing position to the
front speakers.
2. Measure the distance from the
listening/viewing position to the
surround speakers.
3. Subtract the distance to the surround
speakers from the distance to the front
speakers and multiply the result by 3,
if you measured the distances in
meters. If you measured the distances
in feet, don’t multiply the result; it will
be the same as the setting.
a. When setting the delay time for the
Dolby Digital surround modes, the
optimal delay time is the result of
that subtraction. For example, if the
front speakers are 3m away and the
surround speakers are 1m away, the
optimal delay time is figured as
(3 – 1) x 3 = 6. Thus, in this example,
the delay time for Dolby Digital should
be set at 6 milliseconds.
If you measured the distance in feet
instead of meters, don’t multiply the
difference by 3. Thus, if the front
speakers are 10 feet away from the
listening position, and the surround
speakers are 4 feet away, then the
difference will be 10 – 4 = 6, and the
Dolby Digital delay should be set at
6 milliseconds.
b. When setting the delay time for any
Dolby Pro Logic II mode, take the result
of the calculation above and add 15
to obtain the optimal delay time. For
example, if the front speakers are 3m
away and the surround speakers are
1m away, the optimal delay time is
figured as (3 – 1) x 3 + 15 = 21. Thus,
in this example, the Pro Logic II delay
should be set at 21 milliseconds.
Similarly for English measurements,
if the front speakers are 10 feet away
and the surround speakers are 4 feet
away from the listening positon, then
the delay for the Dolby Pro Logic II
modes is calculated at 10 – 4 = 6 + 15
= 21 milliseconds.
NOTE: The DTS, 5CH Stereo, Hall and
Theater modes use a fixed, nonadjustable
delay time.
The Dolby Digital Mode also includes a
separate setting for the center channel
delay mode, since the discrete nature of
these signals makes the location of the
center channel speaker more critical. To
calculate the delay for the center chan-
nel, measure the distance from the pre-
ferred listening position in the center
of the room to both the center channel
speaker and either the left or right speaker.
If the distances are equal, no further
adjustment is required and the center
delay should be left zero. If the distance
to the front speakers is greater than the
distance to the center speaker, you may
wish to reposition the speakers by
moving the front left and front right
speakers closer to the listening position
or the center speaker further away from
the listening position.
If repositioning of the speakers is not
possible, adjust the center delay time,
adding 1 millisecond of center channel
delay for every 30cm (foot) closer to the
listening position the center speaker is
than the front speakers. For example, if
the front left and front right speakers are
each 3m (12 feet) from the listening posi-
tion and the center channel speaker is
2.4m (10 feet) away, the delay is figured
as 300cm (12 feet) – 240cm (10 feet) =
60cm (2 feet), suggesting an optimal
center delay of 2 milliseconds.
To set the delay time, follow these steps:
1. To make the delay settings for the
Dolby Digital mode (this will include
the Center delay setting, and the sur-
round delay for the Pro Logic II mode
will be set automatically), press the
Input Source Selector
!
5
and
select any input that is associated with
a digital input and the Dolby Digital
surround mode.
2. Press the
Delay Button
T
&
.
S DELAY will appear in the Main
Information Display
K
.
3. Press the
Set Button
E
^
.
4. Press the
/
¤
Buttons
C
on the
remote or the
Selector Buttons
%
on the front panel until the desired rear
delay
time for the Dolby Digital mode,
calculated
using the formula for Dolby
Digital above (item a), appears in the
display.
5. Press the
Set Button
E
^
to enter
the setting into the AVR480’s memory.
6. Press the
/
¤
Buttons
C
on the
remote once, so that
C DELAY
appears in the Main Information
Display
K
.
7. Press the
Set Button
E
^
.
8. Press the
/
¤
Buttons
C
%
until
the desired delay time for the center
channel appears in the display.