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Genie Distribution WNET Manual v3
© Tieline Research Pty. Ltd. 2020
9
Genie Distribution WheatNet Input Levels and PPMs
The codec supports 6 digital inputs/outputs, which are available as sources and destinations using
the WheatNet-IP LAN interface.
Important Note:
Inputs can also be configured using the HTML5 Toolbox Web-GUI. See
Configuring Codec Input/Output Settings
Adjusting PPM Meter Reference Scale Settings
By default, the
PPM METERS
on the front of the codec, or in the HTML5 Toolbox Web-GUI, use
dBFS to express nominal operating, headroom and noise floor levels.
The codec can also automatically adapt to different Tieline reference scales. A Tieline codec with
proprietary Tieline session data enabled will automatically adjust the reference level to suit G5 and
G3 codecs, or Report-IT. When connecting to a non-Tieline codec, or a Tieline codec without
session data enabled, the codec will use the
Tieline G5
reference scale setting.
The default Tieline G5 audio reference scale displayed on the PPMs when you connect to a Tieline
G5 codec is -38dBFS to 0dBFS (e.g. Merlin, Genie, Bridge-IT and ViA codec families). Using this
reference scale audio peaks can safely reach 0dBFS without clipping, providing 18dB of headroom
from the nominal 0vu point. The comparison table below outlines the reference scales for G5 and G3
codecs and Report-IT in dBFS, as well as the equivalent dBU scale.
The audio reference level settings in the codec are:
Reference
Level
Description
dBu
dBFS
1
Tieline G5
PPM meter low point
-16dBu
-38dBFS
Nominal 0vu reference level
+4dBu
-18dBFS
Level at which audio will clip/distort
+22dBu
0dBFS
2
Tieline G3
PPM meter low point
-11dBu
-29dBFS
Nominal 0vu reference level
+4dBu
-14dBFS
Level at which audio will clip/distort
+18dBu
0dBFS
3
Report-IT
PPM meter low point
-9dBu
-23dBFS
Nominal 0vu reference level
+4dBu
-10dBFS
Level at which audio will clip/distort
+14dBu
0dBFS
Important Note:
If a codec supports multiple stream programs and the
Auto
(default)
reference level is selected, the first codec to connect will configure the reference level
used for all subsequent connections. I.e. If a G3 codec connects first then the G3 Audio
Reference Level will be configured for all connections.