Telos Zephyr Xstream, User Manual

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USER’S MANUAL
Section 11: THE WORKS – Detailed Menu Reference 208
G.722 acts similarly to the Dual modes discussed above. Audio input A is
encoded and transmitted on "line 1" while Audio input B is transmitted over
"line 2".
Offers 7.5 kHz audio frequency response. Delay is very low at 14 milliseconds.
L2 Stereo
L2 J ‐ Stereo
These work similarly to the equivalent Layer ‐ 3 modes. Two connections are
required.
L2 Stereo offers discrete stereo transmission with 7.8 kHz audio frequency
response when the 48 kHz Sample rate is used if the transmission channel is 56
kbps. It offers 9.8 kHz frequency response when the 48 kHz Sample rate is used
if the transmission channel is 64 kbps.
L2 J ‐ Stereo offers 20 kHz audio frequency response when the sample rate is 48
kHz and 15 kHz response when the sample rate is set to 32 kHz.
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HOT TIP!
Of course you will want to use Layer 3 or AAC when supported at the far end.
We strongly recommend Layer 2 Joint stereo over Layer 2 Stereo when transmitting stereo
material in Layer 2 at 128kbps. While some loss of stereo image will occur, the reduced
compression ratio required will provide noticeably improved fidelity (.i.e. reduced artifacts).
Layer 2 stereo is appropriate only when the two channels to be transmitted are unrelated
sonically and must therefore be kept separate.
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ZEPHYR CLASSIC VS XSTREAM COMPARISON!
Some early Zephyr software releases refer to L2 Stereo as "L2 Dual". We changed the name
for two reasons. This mode cannot be used to send two mono streams to two sites. And,
because phase integrity of the two channels is maintained.
L2 Mono 128
This mode is very common mode used in the voice ‐ over industry. It works in
the same way as the other Mono 128 modes.
Offers 19Hz audio frequency response when the Sample Rate is set to 48 kHz
and 15 kHz response when the Sample Rate is set to 32 kHz.