Extron electronics MediaPort 200 User Manual page 21

Room Volume (Near End)
The master volume control is shown in red (see
mix-points it controls are also shown in red. This control is used to set the master volume or
"listening level" in the local, or "near" room.
When the MediaPort is used with an external DSP with AEC, the Line Out is no longer
connected to a sound reinforcement system, but is instead connected to the DSP. In
this case, volume control is handled in the DSP. Since the Room Volume control in the
MediaPort would no longer be used for room volume, the Room Volume control should be
set to the 0 dB setting, or unity gain, to achieve the best signal to noise ratio between the
MediaPort and the DSP.
Also in this case, the Send to setting in the USB Communications section should be set
to alter the signals being routed to the line output.
settings and the routing that corresponds to those settings.
The figure to the right shows the USB Communications control from the PCS software Mix
page, and the two Send to selections:
• AEC Ref + Line Out (default)
AEC Ref Only
•
Figure 8 and on the next page show the routing scheme for each selection. When
A B
AEC Ref + Line Out is selected, the USB Communications signal is routed to the Line Out
(and the Ref Out, which is unused in this scenario). This setting is used when the Line Out is
connected to a sound system, and not to a DSP.
When AEC Ref Only is selected, USB Communications is not routed to the Line Out, and
is sent only to the Ref Out. This setting is used when the Line Out is connected to a DSP,
and not to a sound system. This is so that program audio and USB communications audio
can be managed separately in the DSP. (Alternatively, this setting can also be used to send
program and USB Communications audio to separate sound systems.)
figure 7 on the previous page) and the
Figure 8 on the next page shows those
MediaPort 200 • Theory of Operation 14