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FM-531HD / May 2013
F M - 5 3 1 H D P R O G U I
VBMS Metering
There are two ways to monitor the amount of process‑
ing being done by the VBMS.
VBMS can be seen on the Analysis Screen on the PRO
GUI or in the Guru GUI. VBMS can also been seen in
PRO GUI in the Limiter gain reduction graph. Its activity
is indicated by the yellow line.
Depending on how hard
the VBMS is driven, one may
or may not see much activity
with VBMS. In fact, only when
a lot of bass is present in source
material will VBMS show any
activity on the meters. This
does not mean VBMS is not
working or acting on the audio.
Digital Output
The Digital Output control adjusts the precise peak audio signal level
at the FM Limiter of the FM‑531HD. The resulting peak output levels in
dBFS are indicated by the front panel and remote GUI bargraph meters.
This control can be set to OFF or adjusted over the range of ‑79.95dBFS
to 0.00dBFS.
Digital output available as AES3 digital signal or baseband192 digital
multiplex signal.
AES3 Digital
DeEmph – When checked, this option applies de‑emphasis to the
FM digital outputs. The type of de‑emphasis is determined by the pre‑
emphasis selected. If no pre‑emphasis is selected, this button is defeated.
PreDelay – When checked, the digital FM output will always be fed
before the diversity delay.
FM Diversity Delay
The FM‑531HD contains an internal digital delay to compensate
for the corresponding delay in the HD Radio codec. The delay sec‑
tion is capable of providing up to ten seconds of compensating delay
insteps of 100 microseconds.
The Coarse
delay is set first to align the analog and HD signals as
closely as possible, and then the Fine delay control is used to trim the
delay to precisely compensate for that in the HD channel. Generally it
is a good idea to set the Fine delay to midrange before adjusting Coarse delay. Resolu‑
tion of the Coarse delay is 50 milliseconds.
The Fine control covers a range of 50 milliseconds in 0.1 millisecond (100 microsec‑
ond) steps. If the Fine control does not set the increment exactly to where it is desired,
double clicking on the delay value text box will open it for manual entry of the delay time.
Summary of Contents for FM-531 HD
Page 2: ...Technical Manual Wheatstone Corporation May 2013 FM HD Digital Audio Processor FM 531hd...
Page 122: ...page A 2 FM 531HD May 2013 A P P E N D I C E S Appendix A General Specifications A 3 Contents...
Page 128: ...page A 8 FM 531HD May 2013 A P P E N D I C E S Appendix B FM 531HD GPI Interface A 9 Contents...
