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6.2 Two FBX Advantages
There are two reasons why the True Mobility
TM
system from Sabine is able to eliminate
feedback while maintaining a high quality
audio signal.
6.2.1 Advantage #1
First, an FBX filter represents a direct hit
on feedback! The FBX targets feedback
without taking a big chunk out of your sound.
Tests prove that a single 1/3-octave EQ
slider pulled down 12 dB removes almost
half the power going to the speakers over a
two-octave range. Furthermore, you can’t
place a graphic EQ filter precisely on the
ringing frequency. If you pull down multiple
sliders in a normal setup, you end up with giant frequency holes in your music (see Figure 6b). On the
other hand, FBX micro-filters are 10 times narrower—you get back up to 90% of the power you lose with
a graphic EQ! That means more gain before feedback and no loss in sound quality.
EXAMPLE: In Figure 6c, a PA sys-
tem was set up using a microphone,
mixer, FBX Feedback Extermina-
tor
®
, power amp and two speakers.
The system’s gain was raised until
the FBX removed nine feedback
points. Next, the FBX was replaced
with a graphic EQ. The EQ was
adjusted while the system gain was
raised to the same level achieved
with the FBX. The frequency re-
sponse curves of each device were
then plotted.
Note how much more of the program
is eliminated using an EQ—whereas only feedback is eliminated using FBX filters.
6.2.2. Advantage #2
The second reason True Mobility
TM
systems are able to remove feedback while maintaining high quality
audio signal is due to the placement of the signal processing in the input chain of the microphone signal.
Many times signal processing (compression and equalization) is placed after the output stage of a
mixer, meaning it is applied to a combination of inputs mixed together into one output and passed through
the processor. Particularly in the case of equalization and feedback control, one consequence of such
a signal path is that filtering applicable to just one microphone is applied to others in the same mix bus.
In other words, unnecessary filtering (albeit very narrow filtering in the case of an FBX filter) may be
applied to microphones that have different feedback frequencies than some of the filters set.
Placing the filtering and other signal processing in the input signal path is a concept called Targeted
Input Processing. It means each microphone so equipped will have customized, unique signal
processing applied—and no unneeded processing.
Sabine True Mobility Wireless Systems give you
- Targeted processing for each microphone
- Increased mobility
- Quiet, fast and easy setup of FBX filters (Our Fastest FBX setup mode!)
Section SIX : FBX Feedback Exterminator
Figure 6c - FBX Filters vs Graphic EQ Filters
Figure 6b - FBX Filters a Direct Hit on Feedback
1/3-octave
EQ filter
Feedback
FBX filter
You get back this
much sound & power
with the FBX!
The grey area
shows you how
much of your
program you
would lose using a
1/3-octave filter to
control feedback
Direct Hit on Feedback!
Содержание TRUE MOBILITY WIRELESS SYSTEM SWM3000
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