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FM-531HD / May 2013
A P P E N D I C E S
a very specialized bass system called “VBMS™,” which stands for “Vorsis Bass
Management System™.” In general terms VBMS gets real bass on the air without
it causing the problems commonly associated with “bass clippers.” .
Using VBMS™ or Vorsis Bass Tools™ to add more Thump & Rumble is quite
easy. By setting the VBMS Style to Soft the algorithm automatically places addi-
tional emphasis on lower bass frequencies. If the Style is set to Hard instead, bass
‘slap’ will be more pronounced and the emphasis on thickening the bass that the
Soft style creates will be reduced.
Vorsis Bass Tools™ in software versions above 2.4.x has a new feature called
“Sub Bass.” This new algorithm places targeted enhancement on the frequencies
between 20Hz and 80Hz, and, unlike the VBMS algorithm, it does not add bass
harmonics. When the Sub Bass control is Off, enhancement of very low frequencies
is disabled and bass energy in that region remains just as it was in the incoming
program material.
Other ways of enhancing these lower frequencies would be to set the Band 1
to Band 2 crossover at 50 or 60 Hz and raise the threshold of Band 1 in the
AGC/Compressor. This will allow very low bass to pass more freely through the
AGC and compressor section, with the lower bands of the 31-band limiter and
VBMS/Bass Tools acting as a safety net to prevent bass-induced distortion. On the
majority of formats we recommended the “Sub Bass” control being left in the “On”
position.
PUNCH/BOOM/TUBBY/WARM
The sound of bass “punch” and “boom” usually fall in the range of 70Hz to
150Hz. “Tubby” on the other hand usually falls between 150Hz and 300Hz. Band 2
of the parametric Equalizer may be used to gently and broadly boost audio in the
range of 75Hz to 120Hz to safely reinforce the “punch” and “boom” of lower bass
without creating undesirable effects such as “tubbiness.”
The enhancement of “punch” and “boom” can be especially tricky because
many listeners’ sound systems don’t have the ability to reproduce lower and sub
bass frequencies. Therefore it’s especially important to use several known reference
systems when adjusting the enhancement of very low frequencies because it is easy
to create distortion or “muddiness.” How many stations have awesome sounding
bass on the PD’s car stereo but end up sounding terrible on clock radios and boom
boxes? Always listen on multiple radios in multiple listening environments to get
the best feel for the effects created by purposeful bass enhancement.
MUD
When someone says that audio is “muddy” they usually mean too much energy
is in the 250Hz to 400Hz range. Sometimes it’s caused by a misadjusted Equalizer
or a processor maladjustment that is allowing an AGC or compressor band to add
too much gain. In most cases it’s a good idea to keep from boosting energy in this
region. In fact, additional clarity and detail can be created by a broad equalization
cut in the range between 180Hz and 400Hz. This surprising little secret can be more
effective at “adding” detail in low bass and midrange than adding equalizer boost
at the same frequencies. It’s true! Try it!
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...