Inovonics FM SiteStreamer+ SOFIA 565, Инструкция по установке и эксплуатации, Страница: 27 / 40

— 25 —
RDS/RBDS:
sets the mode for RadioData between the European
RDS
or the North American
RBDS
standards. Although the two
standards have become more-or-less ‘harmonized’ over the
years, certain RDS features do still differ and will not behave
appropriately with the wrong setting here. The RBDS default
setting is common to North America.
Audio Outputs
The levels for SOFIA 565 audio outputs are individually adjust-
able. Please note the associated comments relating to what
these levels actually mean.
The
Analog Level (dBu):
slider sets the rear-panel XLR balanced
left and right analog outputs to any dBu value between –15dBu
and +15dBu. dB u signifies the unloaded , balanced level from
these outputs, which have a source impedance of 200 ohms.
This means that a 600-ohm-loaded dB m reading will be about
2.5dB lower than the figure shown. However, the concept of
600-ohm sources and terminations in professional audio prac-
tices date back to the days of transformer coupling, leased tel-
ephone lines and ‘repeat coils,’ and the notion of audio signal
impedance matching is nowadays generally regarded as “old
school,” clearly passé.
Also with regard to the analog output level, the dBu notations
beside the slider actually refer to the r.m.s. average level of a
sine-wave tone with a peak value corresponding to 100% FM
carrier modulation (±75kHz monaural carrier deviation at
400Hz).
The
Digital Level (dB
FS
):
slider adjusts the rear-panel XLR AES3
digital program line output between –30dBFS and 0dBFS. Levels
in this case are dBFS peak values at the output, again corre-
sponding to ±75kHz mono-FM carrier deviation. An accepted
and appropriate setting for this slider would be in the neigh-
borhood of –12dBFS, allowing sufficient headroom for FM carri-
er overmodulation, acknowledging that the average off-air pro-
gram level will usually be so uncomfortably close to the peak
level as to eschew a more conservative headroom buffer.
In general, the
Dante/AoIP Level (dB
FS
):
requires the same con-
siderations as the AES digital output and may be set similarly.
Streaming
Outputs
The
Stream
audio output references the Web-listening utility,
which is independent of the Dante-based AoIP streaming. Web-
listening relates to the little loudspeaker icon at the top of each
SOFIA 565 Web interface page, which can be clicked-on by as
many as 10 users at the same time who have Internet access to
the unit. Also note that you can enter the IP address of the unit
in the address bar of any browser, as described on Page 16.
The streaming
Format:
defaults to the popular
MP3
standard,
although it may be reset to
OGG
, a family of audio file types
that may enjoy a slight sonic advantage over MP3.