SABINE 2007 NAVIGATOR Manual page 24

2. You've set as many filters as you need or want, even though you haven't used them all. Press EXIT
to prevent any more Fixed filters from setting, or any of the set Fixed filters from notching more
deeply. Pressing EXIT exits Setup Mode and the FBX Menu window will be displayed.
You are now ready to begin your program!
See the results: In the FBX Menu you can view the parameters of all your FBX Filters. Scroll through
all the filters in the FBX# field. You may edit the type of filter, but not the level (LVL), width (BW), or
frequency (FREQ). You may want to create parametric filters based on the results of your FBX Setup,
then repeat the Setup procedure to maximize system gain.
5.6.1. FBX Setup Mode Cautions & Alternate Setup Procedure
Setup Mode is designed to allow fast and quiet feedback elimination during setup. Setup Mode should ONLY
be used for pre-performance setup. DO NOT USE Setup Mode DURING A PERFORMANCE! This will
produce distorted audio and set filters on music or audio program. Setup Mode also may not work well during
setup in a very noisy environment. To speed up feedback elimination, Setup relaxes the FBX criteria for
distinguishing "good" audio from feedback and places filters more readily. If the environment is noisy, there
is a greater likelihood of placing a filter on audio that is not feedback.
If you are working in a noisy environment you can still get the benefit of the Setup procedure, which is
more gain before feedback. Instead of starting in the FBX Mode Menu, begin in the FBX Global Menu.
This procedure will still eliminate feedback very quickly, though not as quickly as Setup Mode, and without
reducing the volume of the feedback before it is filtered out.
1. Change the LOCK setting to Off. Now the Fixed filters are available to react to feedback.
2. Follow Step Four of the Setup procedure outlined above -- raise the gain for this input channel.
3. Continue raising the gain until you achieve the gain before feedback you require, or you set all the fixed
filters. You can see the results of this procedure in the FBX Menu (shown above).
4. VERY IMPORTANT: Go back to the FBX Global Menu and set LOCK to On. This will lock the fixed
filters and prevent them from going any deeper. If you use the factory default settings you will still have
two dynamic filters available for automatic feedback control during the program.
Whether or not Setup Mode is used, the end result of setting up FBX filters should be identical. Your sound
system will have clearer, louder, feedback-free sound.
5.6.2. FBX Feedback Exterminator - Global Parameters
A unique feature of the FBX Feedback Exterminator is the ability to adjust the way the algorithm reacts
to feedback. Unlike other feedback controllers, you can create and save your own customized versions
of the FBX.
See section 5.1 Input Menus for instructions on using the Global parameters of the FBX.
Sensitivity and Persistence are controls that allow the speed and analysis of the FBX algorithm to match
the type of audio program. Some audio programs, notably certain types of classical music, produce
occasional waveforms that are difficult to distinguish from acoustic feedback. The factory default
Sensitivity and Persistence values should work in almost all conditions; however, you may change them
if necessary to prevent the possibility of triggering a false filter, or to more quickly set the FBX filters.
There is a trade-off between speed of filter placement and how carefully the filter is placed. More
demanding audio sources (that is, program material with musical content that is similar to feedback, like
flutes and organs) may require higher Sensitivity & Persistence settings, which will slightly slow down
the speed of filter placement, but decrease any possibility of mistaking program audio for feedback.
Lower settings are recommended when you need faster reaction during speech-only programs.
S
ECTION
NAV4802 & NAV8802 NAV240, 360, 480
F : O N
IVE PERATING THE
Navigator2 Op Guide 071010 KJS.pmd
AVIGATOR
23