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FM-531HD / May 2013
F M - 5 3 1 H D P R O G U I
always practical in this era of downsizing as there aren’t enough warm bodies to do
the work. So, for stations that feel they need to use a processor ahead of a ratings
encoder, we suggest setting the FM‑531HD multiband control gate between ‑30dB
and ‑20dB and placing the SST in Linear mode. If aggressive AGC is needed, adjust
the AGC Backoff in the FM‑531HD towards 0dB.
• Reverb
– Reverb was originally used as a way to increase density into older
AM transmitters when processing wasn’t sophisticated enough to do the same.
The effect of reverb not only did the trick at the time, it also added a pleasant
sonic texture to the audio that is desired by many stations today. The problem
with reverb units is that the input level controls everything about how the reverb
will sound on the air if the unit is placed directly into the program chain.
A pre‑processor is traditionally used ahead of a reverb unit to prevent excessive
reverb due to sloppy levels from a console. A pre‑processor also sustains program
audio somewhat to get the most out of the decay effect in a reverb unit. Just like
adding an AGC to enhance levels to a Ratings Encoder, the same steps should be
taken to adjust the FM‑531HD to “mate” with the outboard processor. If reverb is
sidechained into a microphone processor and not directly in the audio path, no special
adjustments of the FM‑531HD need be made.
• Analog Telco STL or Aural STL
– Older analog telco lines sometimes need
some pre‑processing in order to keep signal to noise ratios high. Some have
indicated the need for pre‑processing before an aural STL to prevent overshoot.
Again, if you feel the need to use a pre‑processor in either of these situations,
adjustments to the FM‑531HD should be made in concert with the suggestions
above.
It is not recommended that SST be defeated in the presence of an outboard AGC.
If you do choose to defeat the SST, the gain control will become fixed at ‑12dB and
adjustment of the 31‑band limiter drive may need to be made for any offset that the
fixed level creates. It is because of these changes that slowing down SST and the five
band AGC/Compressor be exhausted before sections of the processor are bypassed.
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...
