7847FSEDA Series
Frame Synchronizer and Distribution Amplifier
Page - 40
Revision 0.1
LFE Gain:
This control allows the user to adjust the gain applied to the LFE channel. This control is in
effect only when
LFE Gain
is selected for
LFE Mixing
control. The range for this value can be set from
-20.0dB to 20.0dB in 0.1 dB increments.
Surround Phase:
This control allows the user to choose whether no phase shift (0 degrees) or a 90
degree phase shift is applied to the surround channels before being passed to the down-mix matrix.
Select 0 degree if no 90-degree phase shift is needed. It is required that surround channels are 90-
degree phase shifted for Dolby Prologic I decoding, but if surround channels in the 5.1 audio input are
already 90-degree phase shifted, then the user should select 0 degree to avoid double 90-degree
phase shifting. Normally, the 90 degrees phase shift is applied.
Output Type:
This control allows the user to set the type of audio down-mixing that will be
performed. The user may select from LoRo (Left Only and Right Only), LtRt (Left Total and Right
Total) Prologic I and LtRt (Left Total and Right Total) Prologic II OR may choose to perform a Custom
down-mix.
Custom Downmix Coefficients
When the
Down Mix Type
is set to
Custom
the following equation will be used to generate the down-
mixed audio.
norm
gain
LFE
lfe
Rs
Rs
Ls
Ls
C
C
L
LR
L
gain
levL
levL
lev
lev
÷
×
×
+
°
°
×
+
°
°
×
+
×
+
×
=
)
}
90
/
0
{
}
90
/
0
{
(
norm
gain
LFE
lfe
Rs
Rs
Ls
Ls
C
C
R
LR
R
gain
levR
levR
lev
lev
÷
×
×
+
°
°
×
+
°
°
×
+
×
+
×
=
)
}
90
/
0
{
}
90
/
0
{
(
Where
gain
lfe
is controlled by LFE Mixing and LFE Gain,
gain
is controlled by Output Gain and
norm
is
controlled by Output Scaling Mode and where
lev
LR
,
lev
C
,
levL
Ls
,
levL
Rs
,
levR
Ls
and
levR
Rs
are custom
specified user coefficients. These custom down-mixing coefficients are controlled using the appropriate
slider bars in the
Custom Down mix Coefficients
control section in VISTALINK® PRO (see Figure 5-17).
lev
LR
:
Ranges from 1.000 to –1.000 in increments of 0.001.
lev
C
:
Ranges from 1.000 to –1.000 in increments of 0.001.
levL
Ls
:
Ranges from 1.000 to –1.000 in increments of 0.001.
levL
Rs
:
Ranges from 1.000 to –1.000 in increments of 0.001.
levR
Ls
:
Ranges from 1.000 to –1.000 in increments of 0.001.
levR
Rs
:
Ranges from 1.000 to –1.000 in increments of 0.001.
