AEQ
PHOENIX STRATOS
65
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HIGH: duals the binary rate producing 125 ms additional delay.
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Adaptive/Fixed: you can set up the reception buffer as adaptive or fixed. In the first
case, its size will vary according to the network transmission quality. In fixed mode, its
size will be steady according to manual configuration.
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Adaptive Buffer Max/Fixed buffer length: this is the maximum size of the reception
buffer. When it is defined as adaptive, Phoenix STRATOS will start to shorten it from
this value as the network´s transmission quality allows. If it is defined as FIXED, this
max value will remain, as the buffer’s size won’t be varied during the connection. This
value must be set in milliseconds. The longer the buffer is, packet misses will be less
likely, but base delay will also be longer, especially if the buffer is set to FIXED mode.
In order to help you select the best option for each application, we recommend to use a Fixed
buffer, with a low value (around 100ms) in applications where optimal audio quality is the main
concern (mainly when using PCM modes in suitably sized networks). If the received audio
quality is as expected, and the network allows for it, you can continue adjusting the buffer to
lower values in order to minimize delay, until you find that audio is compromised (as the buffer
size reaches the network maximum jitter value). At this point, just increase the buffer a little bit
to have some margin.
In high-quality PCM connections, you can start using highest quality modes (48KHz, 24 bits,
mono or stereo only if required), and if you can't obtain the desired quality and/or estability (no
noises present) and good delay, you can lower quality progressively until, for example, 16 bit
(CD quality audio).
On the other hand, for applications where lowest possible delay is the main goal, but
transparent audio is not necessary (for example, in voice connections with commentators), it is
better to select the Adaptive Buffer mode, starting from a 1000ms maximum size, approx. If the
network is not too bad, the unit won't increase the buffer to highest values from the network's
jitter value, and it will try to minimize delay continuously. Please not that if the network has very
variable delay, the adjusments required to increase or decrease the buffer size can produce
noticeable artifacts in the received audio, so this method is not recommended for PCM modes
where maximum quality is required, in this case a fixed buffer setting is preferred, as stated
above.
4.5. V35 interface configuration.
In order to establish a V35 communication using CH1 or CH2, first we need to choose V35
option within the “INTERFACE” drop-down menu of the desired channel.
We can access the V35 configuration submenu by clicking on “I/F Setup”. This menu is
described in sections 6.1.4.1 of “AEQ ControlPHOENIX” user’s manual. V35 interface
configuration is limited to selection of the operating mode (permanent or DCD signal controlled)
and an informative window that displays the frequency detected for the incoming clock.
