Table of Contents
Advertisement
15.3.1. The FBX & True Mobility® Advantage
After inventing FBX technology and refining it for over a
decade, Sabine has brought our patented automatic feed-
back control to its fullest realization with the Sabine
SWM7000 True Mobility® wireless systems. Our latest
advance in maintaining the highest 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 conse-
quence of such placement is that filtering appropriate to
only one microphone may be applied to all mics in the
same mix bus. In other words, unnecessary filtering
may be applied to microphones that, due to variations in position and micro-
phone characteristics, will feedback at a different set of frequencies. Al-
though the filters are very transparent, why add filtering if you can avoid it?
And why divide your processing power among multiple signals?
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
unnecessary processing.
With FBX technology, your microphone will finally sound loud enough, every-
one in the audience will understand each word, and feedback will be far less
likely to make an unwelcome and unexpected visit—and you'll be comfort-
able knowing that protection is extended to anywhere a wireless microphone
might be taken.
14.3.2. FBX Fixed & Dynamic Filters
FBX filters come in two flavors, fixed and dynamic. Both operate automati-
cally. There is no audible difference between fixed and dynamic filters in
terms of sonic purity; the difference arises in their application.
14.3.2.1. Fixed FBX Filters
Once they set automatically (see Section 7 for information on setting
filters), fixed FBX filters will NOT change frequency. You can think of fixed
filters as cures for problem frequencies (the "first-to-feedback" frequen-
cies encountered during normal system operation), common to most
locations in the room.
14.3.2.2. Dynamic FBX Filters
Dynamic FBX filters also set automatically, but can change frequency,
on a rotating basis, as the need arises. To help distinguish dynamic
from fixed filters, consider the example of a speaker using a wireless
lavalier microphone, who walks under a ceiling speaker for the first
time. In so doing, he enters a location-specific feedback zone, where
it's possible that a problem frequency may have escaped detection and
notching by a fixed filter. If all fixed filters have been deployed, a dynamic
filter will be set automatically as soon as feedback appears, solving the
problem. Great! But what happens when the speaker then moves away
from the ceiling speaker, and close to a floor monitor? Feedback from
the ceiling speaker is no longer a problem, but a new frequency starts to
squeal. If all fixed and dynamic FBX filters are already set, a dynamic
filter will change, to adjust to the new location. An FBX dynamic filter
thus stands guard if new problem feedback arises after all available
filters have been set, providing a deeper and more flexible level of pro-
tection against the dreaded surprise of feedback.
Other than the ability to change frequency, a dynamic filter is equivalent
to a fixed filter.
FBX Theory & Practice
Fig. 15d - FBX at Work: What FBX Gives Back to your Program
51
Sabine 2.4 GHz Smart Spectrum
®
Wireless
LIT-SWM7000-OG-EN-070615.pmd - rr
Hide quick links:
Advertisement
Table of Contents
