SABINE | FBX1200 | Specifications | SABINE FBX1200 Specifications

SMART FILTERS
OPERATING GUIDE
with
CONTENTS
SECTION ONE — FRONT & BACK PANELS
1.1. FBX2400 Front Panel Controls & LED Indicators
1.2. FBX2400 Back Panel Controls & Connections
2
2
2
SECTION TWO — APPLICATIONS
2.1. FBX Setup for Monitors
2.2. FBX Setup for Entire Mix
2.3. FBX Setup for Single Insert Point
2.4. FBX Setup for Insert Send & Return
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3
3
3
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SECTION THREE — ENGINEERING SPECIFICATIONS
3
SECTION FOUR — OPERATING INSTRUCTIONS
4.1. Before You Begin
4.2. How To Operate your FBX1200 / FBX2400
4
4
5
SECTION FIVE — HOW TO USE FBX FEATURES
5.1. Input / Output Level Switches
5.2. FBX Filter Control
5.3. Important Operating Considerations
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6
6
7
SECTION SIX — TROUBLESHOOTING TIPS
7
SECTION SEVEN — FBX THEORY & PRACTICE
7.1. Introduction to FBX®
7.2. The Advantages of FBX Filters
7.3. Parametric Filters and FBX
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8
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SECTION EIGHT — CAUTIONS & WARRANTY
10
Quick Start Setup on back page
SECTION ONE — FRONT & BACK PANELS
1.1. FBX2400 Front Panel Controls & LED Indicators
2
4
1
8
6
3
5
Note: FBX1200 front and back panels
use the same controls and
input/output configuration
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1. SETUP
Press and hold this button to begin the FBX setup mode. Filter
LEDs (light emitting diodes) will flash 5 times and the SETUP
LED will begin to flash. You are now ready to set FBX filters.
5. RESET DYNAMICS & DYNAMIC FILTER TIMER
Press and hold this button until the Dynamic filter flash and
LEDs go off to reset all Dynamic filters. See Section 5.2.4. for
enabling and setting the Dynamic Filter Timer.
2. READY
The READY LED lights when the automatic FBX setup process has completed, or the READY button has been pressed.
This indicates your unit is ready for operation. The total number of filters available for feedback filtering is 12; in the factory
default setting, your unit will automatically enter READY mode
when the tenth filter is set. Alternatively, you may enter READY
status with fewer Fixed FBX filters in place, simply by pressing
the READY button at any time. Press READY again to lock the
Fixed filters.
6. NUMBER FIXED
Set the number of available fixed filters by pressing the NUMBER FIXED button (6) until the LEDs stop flashing, then release it. The LEDs (8) will begin to light in sequence. When
the LED corresponding to the desired number of fixed filters
lights, press the Number Fixed button to register your selection.
3. BYPASS
Bypass mode takes the unit out of the signal path so that it will
have no effect on the program. In active mode, the unit controls feedback automatically. The red BYPASS LED lights when
the unit is in bypass mode.
4. SIGNAL LEVEL
The LED ladder indicates the signal strength relative to the
FBX's input clip level.
7. FIFTH OCTAVE
Press the button at any time to select wider filters for any new
filters to be set. It is possible to have both 1/5 and 1/10 octave
constant "Q" filters active in one channel simultaneously.
8. FILTER STAGE ACTIVITY
When one of the unit’s filters
is activated, the corresponding LED lights. A blinking
LED indicates the filter that
was most recently activated.
FILTER COLOR KEY
RED
= FBX Fixed, Locked
AMBER = FBX Fixed, Unlocked
GREEN = FBX Dynamic
1.2. FBX2400 Back Panel Controls & Connections
13
9
11
10
12
9. A/C Power Input
The FBX1200 & FBX2400 Series is factory configured to operate at either 115 VAC or 230 VAC. Using the wrong input voltage may cause permanent damage to the unit and will void the
warranty.
10. Fuse
This equipment is fitted with an IEC power inlet incorporating a
built-in fuse holder. To change the fuses in this socket:
1. Disconnect the power cord from the unit.
2. Pull out the fuse holder and remove the old fuse.
3. Install a new fuse into the holder. Replace only with one
of the following fuses:
• 115 VAC: 0.1 A, 10 W, 0.160 A SB fuse
• 230 VAC: 0.06A, 10 W, 0.080 A T fuse
4. Refit the fuse cover.
2
13
14
12
13
14
15
13
16
15
16
11. Power Switch
Previous settings retained during power-off.
12. Quarter-inch Output
TRS balanced or TS Unbalanced output (using a TS unbalanced connector will result in loss of 6 dB gain).
Important: Refer to section 5.2.
13. Input/Output Level Switches
Set to match your desired Input/Output level configurations.
For unity gain set both switches to the same postion.
14. XLR Output
XLR balanced output.
15. Quarter-inch Input
TRS balanced or TS unbalanced input (mixing balanced and
unbalanced connections may result in a 6 dB loss of gain).
Important: Refer to section 5.2.
16. XLR Input
XLR balanced input.
SECTION TWO — APPLICATIONS
Monitor Mix 1
2.1. FBX Setup for Monitors
Monitor Mix 2
Ch. B
OUT
2.2. FBX Setup for Entire Mix
Ch. B
IN
Ch. A
IN
Ch. B
IN
Ch. A
IN
Ch. A
OUT
Right Main Send
Left Main Send
All other Signal
Processing
Ch. B
OUT
Ch. A
OUT
TS "Y" Connector
2.3. FBX Setup for Single Insert Point
IMPORTANT NOTE
Ch. 1
• Mixing balanced and unbalanced connections may result
in a 6 dB loss of gain.
Ch. 2
Ch. B OUT
< Low Z >
< High Z >
< Insert >
Ch. A OUT
Ch. B IN
Ch. A IN
TS "Y" Connector
TRS Connector
TRS Connector
Y Insert Cords (TRS to TS + TS)
2.4. FBX Setup for Insert Send & Return
Ch. 1
TS or TRS Connectors
Ch. A OUT
Ch. A IN
IMPORTANT NOTE
< Insert
Send
Insert >
Return
• Use a ¼-inch TRS plug for
balanced sends/inserts.
Ch. B OUT
Ch. B IN
• Use a ¼-inch TS plug for
unbalanced sends/inserts.
Ch. 2
• Mixing balanced and unbalanced connections may result
in a 6 dB loss of gain.
Insert >
Return
< Insert
Send
TS or TRS Connectors
FILTERS
• 12 independent digital notch filters per channel, controlled automatically from 40 Hz to 20 KHz.
• Filter width: user-controllable - either 1/10 or 1/5 octave*, constant "Q"
• Resolution: 1 Hz
• Time required to find and eliminate
feedback: 0.4 seconds, typical @ 1
KHz
• Number of Dynamic vs. Fixed filters per channel: user selectable.
Last configuration stored in memory.
*Below approximately 200 Hz the feedback filters
become slightly wider to increase the feedback and
rumble capture speed at these low frequencies.
INPUT/OUTPUT**
• Input/Output Maximum Signal
Levels: Balanced +27dBV peak, unbalanced +21 dBV peak
• Output Drive: Unit will perform as
specified driving a load >600 Ohms
• Input Impedance: Balanced or unbalanced >40K Ohms, PIN 2 high
• Output Impedance: Balanced or unbalanced 150 Ohms nominal, PIN 2
high
• Bypass: True power off bypass
• Headroom: +23 dB peak @ 4 dBV
nominal input, balanced
• I/O Connectors: XLR-3 and 1/4"
TRS
PERFORMANCE***
• Frequency response: 20 Hz – 20
KHz +/- 0.3 dB
• Gain matching: +/- 0.2 dB
• Spectral Variation: + .25 dB, 20
Hz to 20 KHz
• SNR - Dynamic Range: >100 dB
• THD: .005% at 1 KHz
< 0.01% 20 Hz – 10 KHz
< 0.025% 10 KHz – 20 KHz
• Dynamic Range: >105 dB
POWER INPUT
• 115 VAC: 100 – 130 VAC 50/60 Hz
• 230 VAC: 200 – 240 VAC 50/60 Hz
FUSE
• 115 VAC, 0.1 A, 10 W, 0.160 A SB fuse
• 230 VAC, 0.06A, 10 W, 0.080 A T fuse
DIMENSIONS
• 1-U rack mount; 19 x 1.75 x 6.25 in.
nominal (rack mountable); 48.3 x
4.5 x 15.9 cm nominal
WEIGHT
• 8.0 lbs. (3.6 kg) nominal
OPERATING TEMPERATURE
• Safe operating temperature: -15 to
+50 degrees centigrade ambient
temperature (5 to 122F)
LIT-FBX1200/2400-OP-EN-050817.pmd - rr
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© 2005 Sabine, Inc.
Tests performed using an Audio Precision
System One model 322 or equal.
SECTION THREE — ENGINEERING SPECIFICATIONS
SECTION FOUR — OPERATING INSTRUCTIONS
4.1. Before You Begin
These instructions apply to both the FBX1200 and the FBX2400. The 2400 is a dualmono version of the 1200. Your FBX Feedback Exterminator will improve any sound
reinforcement system. The instructions presume that you are familiar with the fundamentals of sound reinforcement.
4.1.1. Where the FBX fits in your sound system:
The most common patch point is between the output of the mixer and the input of
a power amp. In this position, the FBX can sense and eliminate feedback occurring in any channel of the mixer. An even better solution is on a mixer insert point
for a single channel, or a subgroup (see application diagrams in Section Two —
Applications). This targets the feedback control to the mics that need it.
Note: If you’re using a mixer with unbalanced 1/4" outputs, you must use standard
unbalanced cables and connectors when connecting it to the FBX. Similarly, if
your mixer is wired for balanced 1/4" Tip-Ring-Sleeve (TRS) outputs, you must use
that type of connector. If you don’t, you may experience a loss of gain (up to 6 dB)
when using the FBX. This can occur if either side of the balanced output is grounded
at any point (or when mixing balanced and unbalanced inputs and outputs).
4.1.2. A note about graphic equalizers:
The FBX is designed to replace the graphic equalizer’s function for eliminating
feedback. In many applications, such as churches, auditoriums or small acoustic
ensembles, the mixing board provides all the tonal control that is necessary. The
FBX can replace the graphic EQ altogether in some applications; however, a graphic
equalizer may be beneficial to shape a system's total performance. If you do want
to use an equalizer, place the FBX after the EQ in the signal path. Use the EQ’s
controls to shape the tonal response of the sound system, but DO NOT NOTCH
FOR FEEDBACK.
4.1.3. Understanding FIXED and DYNAMIC filters
Before operating the FBX, you need to understand the two types of FBX filters:
FIXED and DYNAMIC. FIXED FILTERS retain their frequency center-points until
the unit is reset by the user. The system’s gain before feedback is limited primarily
by the number of fixed filters; i.e., increasing the number of fixed filters increases
the system’s gain before feedback. In addition, you can LOCK the fixed filters so
they do not get any deeper. Locked fixed filters are no longer adaptive. The FBX's
DYNAMIC FILTERS control intermittent feedback that comes and goes throughout the program. They are continually reset automatically to different frequencies
as new feedback occurs during the program. For most applications, the optimal
setting is nine FIXED and three DYNAMIC FILTERS. This is the factory default.
4.1.4. Setup & Ready
Your FBX Feedback Exterminator is either in Setup mode or in Ready mode.
Setup Mode: It’s quick and quiet, but use this mode for setup only – do not use
the FBX for your program while in Setup mode. Think of Setup mode as your key
to achieving one of the main benefits of the FBX: getting more gain before feedback. In Setup mode you will be raising the gain of your system so the FBX can
place transparent filters (Fixed Filters) that will allow you to get all the gain you
need for a loud and clear show. In Setup the FBX is very sensitive so do not talk
into the mics during setup, and try to keep room noise to a minimum. If the room
is noisy, then go into Ready mode and raise your gain while the fixed filters are still
unlocked (flashing Ready LED).
Ready Mode: Let the show begin. Your fixed filters are eliminating feedback and
giving you extra gain, and your dynamic filters are ready to jump on any new feedback during the show. In this mode your fixed filters are either locked (red LEDs)
or unlocked (amber LEDs). We recommend locking your fixed filters for the show.
But if you don’t have time for the Setup mode, or if the room is just too noisy during
setup, then you can start off by unlocking the fixed filters. Leaving the fixed filters
unlocked allows them to get deeper if needed, which can be handy if you need to
get more gain before feedback. But once your system stabilizes we recommend
you lock the fixed filters for the duration of the show!
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4.2. How To Operate your FBX1200 / FBX2400
Follow these procedures to get maximum gain before feedback
1
Place equipment & make connections.
a. Set up one FBX channel at a time.
b. Place speakers and microphones in performance positions.
b. DO NOT TALK INTO YOUR SYSTEM while in Setup mode.
c. Set Input and Output levels on FBX back panel (see Section 5.1.1.
for details). Start with all buttons pushed in.
d. If you are using a graphic EQ, adjust only for the desired tonal
qualities, but DO NOT NOTCH FOR FEEDBACK.
e. Adjust the level for each mixer channel, and set the sound system’s
master volume to minimum.
2
Power Tips
a. Patch your FBX1200 or FBX2400 into system and make all connections (refer to pages 2 and 3 for connection options).
c. See Section 5.2. FBX Filter Control for information on:
• Changing the number of Fixed
vs. Dynamic filters
• Selecting and mixing 1/10- &
1/5-octave filters
• Enabling and setting the Dynamic Filter Timer
Push SETUP button until all LEDs stop flashing and the
SETUP light flashes on its own. Setup mode clears all Fixed &
Dynamic filters. Do not use Setup mode during your performance.
3
Slowly raise the gain on the mixer or amp until the FBX
eliminates the first few feedback tones.
DO NOT TALK INTO THE MICS. The FBX will quickly begin to find and
remove feedback. The first Fixed filter set will be heard as a quiet feedback
chirp and shown as an amber LED. As you slowly raise the gain, more
feedback chirps will be heard, and more amber LEDs will light.
a. If you are using stationary microphones:
Front panel filter LEDs
lighting as gain is raised
and Fixed filters are set.
Continue raising the gain until all filter LEDs cycle back and forth in
sequence. This is your indication that the FBX is exiting setup mode.
IMPORTANT: Reduce gain slightly. You are now in READY (performance) mode, with the Fixed filters locked and the blue Ready
light on. Begin the show!
b. If you are using wireless microphones:
c. You may quit Setup mode at any time prior to its automatic exit by simply
pressing the READY button (blue READY LED will flash). Press it again at
any time to lock the Fixed filters (blue READY LED stays on). Whether locked
or unlocked, pressing the READY button before Setup mode automatically
finishes will enable ready-to-operate status, but with fewer fixed FBX filters in
place. Dynamic FBX filters are still available to eliminate new feedback, regardless of how or when SETUP mode is exited. Begin the show!
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If you do not have time to use Setup Mode:
Push the READY button -- the blue LED flashes indicating the fixed filters
are unlocked. Begin your show, and once several fixed filters are set we
recommend you lock them by pushing ready again (blue LED stays lit). You
won't get all the potential benefit of increased gain before feedback, but you
will get automatic feedback control during your performance.
FILTER COLOR KEY
FBX Filters
LEDs
Fixed, Locked
RED
Fixed, Unlocked AMBER
Dynamic
GREEN
Ready LED
Steady BLUE
Flashing BLUE
Either
Fixed & Dynamic Filters
See Section 4.1.3. for details on
the differences between Fixed and
Dynamic FBX filters, and Section
5.2.2. for instructions on changing
the balance of Fixed versus Dynamic filters.
LIT-FBX1200/2400-OP-EN-050817.pmd - rr
© 2005 Sabine, Inc.
You can get more gain in a variety of locations. To do this, lower the system
gain after the first few filters are set, then move the microphone to another
area where it will be used and raise the gain slowly as before. Repeat this
process while you continue raising the gain until all filter LEDs cycle
back and forth in sequence. This is your indication that the FBX is exiting
setup mode.
IMPORTANT: Reduce gain slightly. You are now in READY (performance) mode, with the Fixed filters locked and the blue Ready
light on. Begin the show!
5
SECTION FIVE — HOW TO USE FBX FEATURES
5.1. Input / Output Level Switches
Use the two-position switches on the back panel of your FBX1200 / FBX2400 to compensate for input level or output level
requirements. NOTE: For unity gain (recommended), set the channel's input & output level switches to the same setting.
NOTE: Mixing balanced and unbalanced connections may result in a 6 dB loss of gain.
5.1.1. Setting Levels: Set both Input & Output switches the same for Unity Gain
POSITION
INPUT LEVEL SWITCHES
OUTPUT LEVEL SWITCHES
OUT
Accepts low level input up to +6 dBU
Outputs at low level, for sending signal to low-level devices or some insert
points. See Section 2 for more information on applications.
Accepts high level input up to +24 dBU
Outputs at high level, for most line-level devices. See Section 2 for more
information on applications.
IN
5.2. FBX Filter Control
5.2.1. Selecting Filter Width
If you’re using the FBX for a music application, the standard 1/10-octave constant “Q” filter is most effective. However, in
spoken word applications, such as lectures or teleconferencing, we recommend using the wider 1/5-octave filter for more
robust feedback control. You may enable the 1/5-octave filters by pressing the FIFTH OCTAVE button, and the built-in LED will
light. Only filters set after pressing the button in will be 1/5-octave. Press the button again to set subsequent filters to
standard 1/10-octave filters.
5.2.2. Setting Number of Fixed vs. Dynamic Filters
To change the number of Fixed filters from the factory default of 9 Fixed and 3 Dynamic per channel, push the NUMBER FIXED
button for 4 seconds. The filters LEDs will flash 4 times and then go out. Release the NUMBER FIXED button, and the LEDs
will begin to light in sequence. When the LED corresponding to the desired number of Fixed filters lights, press the NUMBER
FIXED button again.
IMPORTANT TIP: You can mix 1/10- and 1/5-octave filters in the same channel. If you have an especially bad feedback
problem, try making the first few filters 1/5-octave filters.
5.2.3. Resetting FBX Filters
All FBX filters: To reset all FBX filters, follow the directions in Section 4.2.
Dynamic FBX filters only: To reset only Dynamic filters, press RESET DYNAMICS until the current Dynamic filter LEDs flash and then turn off. Release the button.
Dynamic FBX filters: Factory default of 3 Dynamic
filters flashing just before reset.
5.2.4. Dynamic Filter Timer
The Dynamic Filter Timer, when enabled, automatically resets Dynamic filters after a user-selected time has passed (refer
to Timer Settings chart at right).
5.2.4.1. Set the Dynamic Filter Timer
1. Press and hold the RESET DYNAMICS button. The Dynamic
LEDs flash twice and reset. Continue holding the button and the
current Dynamic Filter Timer set- Current Dynamic Timer (disabled) setting being indicated on third flash.
ting will flash twice (filter LEDs 1-5,
see Filter Timer Chart at right).
2. Release the RESET DYNAMICS button and filter LEDs 1-5 will cycle through the possible
timer settings.
3. Press RESET DYNAMICS again at the desired timer setting. LEDs will flash twice
(including filter LEDs indicating the current timer setting). Your Dynamic Filter Timer is
now set. The timer starts individually for each Dynamic filter.
TIMER SETTINGS
Off
1 min.
5 min.
30 min.
60 min.
5.3. Important Operating Considerations
5.31. Power-Off Memory
The FBX stores the positions and depths of the filters in nonvolatile internal memory when the unit is turned off or during a power
failure. The unit will return all filters to their previous frequencies and depths when it is turned back on.
5.3.2. Bypass Mode
The FBX has a true power-off bypass. The signal is unaffected in Bypass mode even if the unit is turned off. Note that if a
combination of balanced and unbalanced inputs and outputs is used, the signal may be disconnected or attenuated in Bypass.
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5.3.3. Setup Mode
NOTE: Setup mode is for pre-performance audio setup only, and will cause distortion in your audio program if left on during
performance. You must follow the setup procedure outlined in the previous section, and do not play program during Setup
mode. Otherwise the FBX will clip and filters may be set improperly. (Clip level is set to the lowest level so the feedback clips
quickly; therefore, your program will also be clipped in setup mode. Be sure a dynamic filter is set, and if one isn’t, press the
READY button before your program begins.) You’ll know the FBX1200 / FBX2400 is in setup mode when the SETUP button
is lit. NOTE: You can manually override Setup mode if necessary.
5.3.4. Mobile vs. Stationary Microphones
One significant advantage offered by the Sabine family of FBX Feedback Exterminator products is their ability to adapt to changing
acoustical relationships involving sound system components in various applications. One major source of potential feedback
problems arises in situations with wireless microphones, when the user of the wireless mic is moving around the performance
area. As a microphone moves in a sound space, with varying degrees of proximity to the speakers and varying acoustic
responses, feedback frequencies may shift. In such a situation, feedback-free mobility may be more important a concern than
maximum system gain.
For this reason we recommend setting FBX filters for mobile microphones by moving to the various possible microphone
locations and setting filters for those locations. As the Setup instructions show, raise the system gain and set the FBX filters in
each predictable location.
In some situations, increasing the number of dynamic filters (versus fixed FBX filters) may allow a second layer of defense
against new feedback from new locations. This technique is recommended if you cannot predict where the performer may
roam. But fixed FBX filters placed in the setup procedure are still your best bet because the feedback filters are already set.
Q. Can I place the unit in the mixer effects loop?
A. Avoid this configuration. You can configure the system this
way only if each effects send of each mixer channel is set
so that all of the signal is routed completely through the
effects loop. You cannot mix dry signal with effects signal
and still control feedback.
Q. The signal input LEDs do not light. The unit will not catch
feedback. Why?
A. The unit is not in the signal path. Check the connections.
Be sure that the program is interrupted when the input is
disconnected from the back of the unit.
Q. Can I mix balanced and unbalanced inputs and outputs?
A. Yes. An unbalanced input and balanced output is compatible. However, a balanced input and unbalanced output will
result in a 6 dB loss of dynamic range. Refer to section
5.3.5. for more details.
Q. Why does one of the FILTER ACTIVITY LEDs blink?
A. The last filter to be automatically updated blinks. During
normal operation, the blinking will move from filter to filter
as they are reset. This gives the user a visual confirmation
that the unit is responding to new feedback and is functioning properly.
Q. Sometimes during the initial setup, the first filter LED will
blink before any feedback has been introduced into the
system. Why?
A. The FBX will set a filter if the system has a hum. Check for
bad grounds. Try resetting the filters and/or the Ground
switch on the rear panel.
mode, hold down the SETUP and RESET DYNAMICS buttons
at the same time. Refer to section 5.2. for more details.
Q. Why does my system sound thin and muffled?
A. Place the FBX in BYPASS MODE. If the system still sounds
thin, your problem is probably improper use of a graphic
EQ. If the problem is really the FBX, re-initialize the system
and make sure the READY button LED is on steadily.
Q. Why does my program sound clipped and distorted?
A. Make sure you are not in Setup mode. Setup mode turns
off automatically after the first dynamic filter is set, or you
can turn it off manually by pressing the READY button. See
Section 4.3.3. for information on Setup mode.
Q. Can I patch two FBX channels together for twice the
filters?
A. Yes; connect the output of one FBX channel to the input of
the other channel. Place the FBX between the output of
the mixer and the input of a power amp, and set up the
channels sequentially. When combining channel A with
channel B on an FBX2400, bypass channel B while setting
up channel A, then lock channel A’s fixed filters (all channel
A’s filters should be fixed) by pressing channel A’s READY
button on the front panel after setup. The blue READY LED
should remain lit.
Q. Why doesn't the FBX1200 & FBX2400 Series filter feedback immediately?
A. Four possible reasons:
1. Lower frequencies may take longer than higher ones.
2. Check input level of signal at the unit and set gain so
the signal level LED's on the unit light up.
Q. Why do I have a loss of 6 dBs at the outputs?
3. It may be patched in an "effects loop", not directly in the
signal path. This WILL NOT WORK.
A. Your outputs are connected to an unbalanced connector,
causing a loss of 6 dB through the box. You can put your
FBX in unbalanced mode, giving the box a boost of 6 dB at
the outputs. To change between balanced and unbalanced
4. You may have used all 12 filters. Dynamic filters will
continue to operate by notching feedback frequencies
as they occur, but ultimately, gain will exceed filter
capacity.
LIT-FBX1200/2400-OP-EN-050817.pmd - rr
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© 2005 Sabine, Inc.
SECTION SIX — TROUBLESHOOTING TIPS
Q. Can I place the FBX in the mixer’s EQ loop?
A. Yes.
SECTION SEVEN — FBX THEORY & PRACTICE
7.1. Introduction to FBX®
WHY FBX? Feedback is certainly the most pervasive challenge to the audio industry.
The potential appearance of sudden, loud, out-of-control feedback is every sound
engineer’s and musician’s nightmare. Unlike more subtle audio quality problems or shortcomings, feedback is embarrassingly obvious — it disturbs the performer, the audience,
and the technician, and can damage equipment and just generally ruin your day.
Feedback is a potential problem in any amplified sound system that places a microphone
or pickup in proximity to a loudspeaker. Poor acoustical conditions or misguided use by
unsophisticated sound system operators only aggravate the situation. To make matters
still worse, a non-Sabine variety of wireless microphone adds yet another level of feedback danger to the picture. Since feedback erupts whenever the distance, location, and
gain relationships between a speaker and a microphone reach a critical combination, a
mic that can move anywhere results in an ever changing potential for feedback. A step in
the wrong direction may change a clear sound to a piercing shriek in less than a second.
This enhanced potential for feedback with a wireless system gets worse if lavalier microphones are used. Such microphones are usually placed farther from the mouth than
handheld or head set microphones, thus requiring more gain. Also, the polar pattern of a
lavalier microphone is frequently omnidirectional. Thus, the likelihood of feedback increases, due to the microphone’s increased off-axis sensitivity to the sound emanating
from the loudspeakers.
The Sabine FBX1200 and FBX2400 systems solve feedback problems by precise attenuation of very narrow bands of feedback-prone frequencies. The process is automatic,
simple to use, adaptable to changing acoustical conditions and relationships, powerful in
its application, and has minimal consequences to the audio fidelity of the signal. We call
this automatic filter an FBX Feedback Exterminator® filter, or FBX filter for short.
-10 dB cut at 500, 630, 1K, 1.25K, 1.6K & 2K Hz
If the graphic EQ really had 1/3 octave
filter widths, the frequency response
curve would vary 6 dB between sliders.
This would ruin the sound.
Graphic EQs usually use one-octavewide overlapping filters that provide
much smoother frequency response
curves. Notice that the overlapping filters add together to cut -16 dB when
the sliders are only pulled down -10 dB.
7.2. The Advantages of FBX Filters
Before the invention of FBX, the most common device for controlling feedback was the
31-band graphic EQ. However, an FBX filter offers three distinct advantages over graphic
filters.
1. First and most obvious is the automatic nature of FBX filters. When feedback occurs,
FBX responds more quickly than even the most experienced engineer. Automatic
FBX placement works even in the presence of audio program material, intelligently
distinguishing feedback from music or speech.
2. A second advantage is that FBX micro-filters are precisely placed anywhere feedback
occurs (with 1 Hz resolution), while graphic EQ filters are limited to 31 fixed center
points. An FBX filter represents a direct hit on feedback! In contrast, a graphic EQ
filter can only approximate the exact frequency of the feedback, and the filter (or
filters) with the closest center frequency must be pulled down. Such filters are deepest at their centers, and such imprecise attenuation takes a big (and unnecessary)
chunk out of your sound (see figure 7a).
3. Increased clarity and gain-before-feedback are further accomplished by the third and
most important advantage of FBX: Sabine’s micro-filters are ten times narrower than
31-band EQ filters. Using FBX micro-filters will return up to 90 percent of the power
removed by EQ filters.
Here’s a good place to make a very important distinction. Graphic EQ filters are typically
called “1/3-octave,” but it’s important to understand that this term refers to the spacing of
the filter centers (1/3-octave apart), and not the width of the filter (usually a full octave).
Graphic filters thus overlap one another, and affect frequencies well above and below the
center point frequency, including frequencies of adjacent bands. This makes graphic equalizers very practical tools for shaping sound “with broad strokes,” such as dialing in overall
system EQ, but results in destructive audio quality overkill when they are used to eliminate feedback. A graphic equalizer would need more than 10,000 narrow-band sliders to
be as precise and powerful as your FBX.
As an example of the power of FBX, figure 7b shows test results measured with a PA set
up consisting of a microphone, mixer, FBX Feedback Exterminator®, power amp and two
speakers. The system’s gain was first 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 response curves
of each device were then plotted and are compared in figure 7b. Note how much more of
the program (the “good audio”) is eliminated using an EQ — whereas only feedback is
eliminated using FBX filters.
8
Fig. 7a.
7.3. Parametric Filters and FBX
Of course, many savvy sound engineers, realizing the limitations
of graphic equalizers in removing problem feedback, prefer to use
a different type of equalizer, called a parametric EQ, for such applications. If you’re one such audio engineer, you’ll be comforted to
know that FBX filters share much in common with parametrics.
Compared to graphic filters, parametrics allow more precise adjustments — specifically, control of filter width, the amount of boost
or cut, and the mid-band frequency of the filter. This greater precision, however, comes at a price, as parametric filters are not nearly
as intuitive or simple to use as graphic equalizers.
Nothing, however, is easier to use than an FBX filter, which enjoys
the precision of a parametric filter, yet deploys instantly and automatically whenever feedback is detected. Effectively, an FBX filter
is a parametric filter set to a tenth-octave width, restricted to cutonly activity, and automatic in its choice of frequency band.
Fig. 7b.
7.3.1. 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 protection
against the dreaded surprise of feedback. Other than the ability to change frequency, a
dynamic filter is equivalent to a fixed filter.
7.3.2. Balancing Fixed & Dynamic Filters
Your FBX1200, and each channel of your FBX2400, offer a total of 12 FBX filters (combined fixed and dynamic), which can be used as needed to exterminate feedback. After
years of experience and experimentation, Sabine has settled upon a default balance of 9
fixed and 3 dynamic filters, set at the factory. This default condition can be changed to
any combination you require.
If you follow setup instructions for setting FBX filters, your FBX1200/FBX2400 will automatically exit SETUP mode (enter READY status) after all fixed filters, and the first dynamic filter, have set. In the default condition, this means you will have set ten filters (nine
fixed and one dynamic), with two dynamic filters still not set and remaining on standby
alert. If you wish to set fewer filters, press the READY button before SETUP automatically exits, after you have set enough filters to safely achieve your desired gain level. In
that case, in the factory default condition, you will reserve three available dynamic filters
for standby.
7.3.3. FBX Filter Width
Sabine’s experience and testing with filters and sound quality alone led us to decide upon
a default FBX filter width of .10 (one-tenth) octave as the optimal notch width, able to
eliminate feedback without affecting music programs. If, with all filters properly set, feedback is still a problem, FBX filters may be set to .20 (one-fifth) octave width. This wider
filter setting will help to better eliminate feedback trouble areas, but may also affect music
programs slightly. Therefore, the wider setting is generally considered to be appropriate
where speech (less demanding than music) is the primary application. You can globally
change FBX filter width by pressing the FIFTH button on the front panel. The width of any
set filter will always be determined by the position of the switch at the time the filter is
created.
© 2005 Sabine, Inc.
7.3.4. Who Benefits from FBX?
Virtually every sound system will be improved with the Sabine feedback control. Singers
and speakers who do not have sound technicians can now increase their monitor or
house system volume so they can hear themselves clearly and with full fidelity, without
worrying if their microphones will suddenly squeal if they move to the wrong place.
Auditoriums and churches of all sizes will enjoy reliable feedback control. Hotels and
conference centers around the world can offer meeting rooms with microphones that
won’t howl during programs. Sabine FBX systems can be installed in theaters, schools,
sports arenas, courtrooms, teleconferencing rooms, intercoms or interactive remote classrooms — anywhere one or multiple microphones are used.
LIT-FBX1200/2400-OP-EN-050817.pmd - rr
9
SECTION EIGHT — CAUTIONS & WARRANTY
Warning! This equipment must be earthed.
Caution! Risk of electric shock. Do not open.
Caution! Shock hazard. Do not remove covers. No user serviceable parts
inside. Refer servicing to qualified service personnel.
Warning! To reduce the risk of fire or electric shock, do not expose this
product to rain or moisture.
Warning!
The FBX1200 & FBX2400 Series is designed to operate from standard
AC power. Please be sure the power in your area is compatible with the
power requirements marked on the rear of the unit. Using the wrong
input voltage may cause permanent damage to the unit and will void
the warranty.
Attention! Cet appareil doit être relié à la terre.
Attention! Risque de choc électrique; ne pas ouvrir.
Attention! Risque de choc; ne pas oter les capots. Aucune pièce accessible à
l'intérieur. S'addresser à un technicien qualifié.
Attention! Pour réduire le risque d'incendie ou de choc électrique, ne pas
laisser l'appareil sous la plouie ou à l'humidité.
The FBX1200 & FBX2400 Series is supplied with one of the following AC
power cords:
Japan
100 VAC
U.S./North America
120 VAC
Continental Europe
230 VAC
United Kingdom
240 VAC
Australia
240 VAC
Achtung! Dieses Gerät muss schutzgeerdet sein.
Achtung! Gefar eines elektrischen Stormschlags. Gehause nicht öffnen.
Achtung! Gefar eines elektrischen Stormschlags. Gehäuse nicht öffnen. Keine
con Benutzer zu bedienenden Teile im Geräteinneren.
Überlassen Sie das Gerät zu Servicezwecken nur geschultem Fachpersonal.
Um Brandgefar oder das Risiko eines elektrischen Schlags auszuschließen,
das Gerät vor Nässe und Feuchtigkeit schützen.
Advertencia! Este equipo debe estar conectado a tierra.
Precaución! Reisgo de descarga eléctrica. No abrir.
Precaución! Riesgo de descarga eléctrica. No desmontar las tapas. Piezas
interiores no reparables por el usuario. Reparable sólo por personal
cualificado.
Advertencia! Para reducir el riesgo de incendio o de descarga eléctrica no
exponga este producto a la lluvia o humedad.
FCC Statement:
This device complies with Part 15 of the FCC Rules. Operation is subject to the
following conditions: (1) This device may not cause harmful interference; and (2)
This device must accept any interference received, including interference that
may cause undesired operation. Warning: Changes or modifications to this unit
not expressly approved by the party responsible for compliance could void the
user's authority to operate the equipment.
NOTE: This equipment has been tested and found to comply with the limits for a
Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can
be determined by turning the equipment off and on, the user is encouraged to try
to correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different
from that to which the receiver is connected.
• Consult the dealer or an experienced radio TV technician for help.
Canadian Compliance Statement
This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the
Canadian Department of Communications.
Le present appareil numerique n'emet pas de bruits radioelectriques depassant
les limites applicables aux appareils numeriques de la class B prescrites dans le
Reglement sur le brouillage radioelectrique edicte par le ministere des Communications du Canada.
Caution!
Replace the fuse with a fuse of exactly the same rating
specified on the rear of the product.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Japanese EMI Compliance Statement
14.
Read all safety and operating instructions before using this product.
All safety and operating instructions should be retained for future
reference.
Obey all cautions in the operating instructions and on the unit.
All operating instructions should be followed.
Use only shielded audio and data cables.
This product should not be used in the presence of moisture or rain,
or near any water, i.e., a bathtub, sink, swimming pool, wet basement, etc.
This product should be located so that its position does not
interfere with proper ventilation. Do not use in direct sunlight. Do not
place flat against a wall or in a built-in enclosure that will impede the
flow of cooling air.
This product should not be placed near a source of heat such as a
stove or radiator.
Connect only to a power supply of the type marked on the unit
adjacent to the power entry module.
Never break off the ground pin on the power supply cord.
Power supply cords should always be handled carefully. Never walk or
place equipment on power supply cords. Periodically check cords for
cuts or signs of stress, especially at the plug and the point where the
cord exits the unit.
The power supply cord should be unplugged when the unit is to be
unused for long periods of time.
Care should be taken so that objects do not fall and liquids are not
spilled into the unit through the ventilation holes or any other
openings.
This unit should be checked by a qualified service technician if:
A. The power supply cord or plug has been damaged.
B. Anything has fallen or been spilled into the unit.
C. The unit does not operate correctly.
D. The unit has been dropped or the enclosure damaged.
15. The user should not attempt to service this equipment. All
service work should be done by a qualified service technician.
OSHA 2201; 1995 revised.
10
CAUTION
EXPOSURE TO EXTREMELY HIGH NOISE LEVELS MAY CAUSE A PERMANENT HEARING LOSS. INDIVIDUALS VARY CONSIDERABLY IN SUSCEPTIBILITY TO NOISE INDUCED HEARING LOSS, BUT NEARLY EVERYONE WILL LOSE SOME HEARING IF
EXPOSED TO SUFFICIENTLY INTENSE NOISE FOR A SUFFICIENT TIME. THE U.S.
GOVERNMENT’S OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA)
HAS SPECIFIED THE NOISE LEVEL EXPOSURES AT RIGHT AS PERMISSIBLE :
ACCORDING TO OSHA, ANY EXPOSURE IN EXCESS OF THE ABOVE PERMISSIBLE
LIMITS COULD RESULT IN HEARING LOSS. EAR PLUGS OR PROTECTORS IN THE
EAR CANALS OR OVER THE EARS MUST BE WORN WHEN OPERATING THIS DEVICE IN ORDER TO PREVENT A PERMANENT HEARING LOSS, IF EXPOSURE IS IN
EXCESS OF THE LIMITS AS SET FORTH ABOVE. TO ENSURE AGAINST POTENTIALLY DANGEROUS EXPOSURE TO HIGH SOUND PRESSURE LEVELS, IT IS RECOMMENDED THAT ALL PERSONS EXPOSED TO EQUIPMENT CAPABLE OF PRODUCING HIGH SOUND PRESSURE LEVELS SUCH AS THIS DEVICE BE PROTECTED
BY HEARING PROTECTORS WHILE THIS UNIT IS IN OPERATION.
DURATION PER DAY, HOURS
8
6
4
3
2
1-1/2
1
1/2
1/4 or less
SOUND LEVEL dBA SLOW
RESPONSE
90
92
95
97
100
102
105
110
115
http://www.osha.gov
1926.52(d)(1)
LIMITED WARRANTY
Ces clauses de garantie ne sont vaiables qu’aux Etats-Unis et au Canada. Dans tous les autres
pays, les clauses de garantie et de maintenance sont fixees par le distributeur national et assuree
par lui selon la legislation en vigueur.
Diese Garantie ist nur in den USA and Kanada gultig. Alle Export-Produkte sind der Garantie und
dem Service des Importeurs des jewelligen Landes untervorfen.
Esta garantia es valida solamente cuando el producto es comprado en E.U. continentales o en
Canada. Todos los productos que sean comprados en el extranjero, estan sujetos a las garantias
y servicio que cada distribuidor autorizado determine y otrezca en los diferentes paises.
ONE-YEAR LIMITED WARRANTY/REMEDY
SABINE, INC. (“SABINE”) warrants this product to be free from defects in material and
workmanship for a period of one (1) year from date of purchase PROVIDED, however, that this
limited warranty is extended only to the original retail purchaser and is subject to the conditions,
exclusions and limitations hereinafter set forth:
CONDITIONS, EXCLUSIONS AND LIMITATIONS OF LIMITED WARRANTIES
These limited warranties shall be void and of no effect if:
a.The first purchase of the product is for the purpose of resale; or
b.The original retail purchase is not made from an AUTHORIZED SABINE DEALER; or
c. The product has been damaged by accident or unreasonable use, neglect, improper service
or maintenance, or other causes not arising out of defects in material or workmanship; or
d.The serial number affixed to the product is altered, defaced or removed; or
e.The power supply grounding pin is removed or otherwise defeated. In the event of a defect in
material and/or workmanship covered by this limited warranty, Sabine will repair the defect in
material or workmanship or replace the product, at Sabine’s option; and provided, however,
that, in any case, all costs of shipping, if necessary, are paid by you, the purchaser.
WARRANTY REGISTRATION CARD SHOULD BE COMPLETED AND RECEIVED BY SABINE
WITHIN FOURTEEN (14) DAYS OF THE DATE OF YOUR PURCHASE.
In order to obtain service under these warranties, you must:
a. Bring the defective item to any Authorized SABINE DEALER and present therewith the
ORIGINAL PROOF OF PURCHASE supplied to you by the AUTHORIZED SABINE DEALER
in connection with your purchase from him of this product. If the DEALER is unable to provide
the necessary warranty service, you will be directed to the nearest other SABINE AUTHORIZED DEALER which can provide such service. OR
b. Ship the defective item, prepaid, to:
SABINE, INC.
13301 HIGHWAY 441
ALACHUA, FL 32615-8544
Includetherewith a complete, detailed description of the problem, together with a legible copy
of the original PROOF OF PURCHASE and a complete return address. Upon Sabine’s receipt
of these items:
a. If the defect is remedial under the limited warranties and the other terms and conditions
expressed have been complied with, Sabine will provide the necessary warranty service to
repair or replace the product and will return it, FREIGHT COLLECT, to you, the purchaser.
b. Sabine’s liability to the purchaser for damages from any cause whatsoever and regardless of
the form of action, including negligence, is limited to the actual damages up to the greater of
$500.00 or an amount equal to the purchase price of the product that caused the damage or
that is the subject of or is directly related to the cause of action. Such purchase price will be
that in effect for the specific product when the cause of action arose. This limitation of liability
will not apply to claims for personal injury or damage to real property or tangible personal
property allegedly caused by Sabine’s negligence. Sabine does not assume liability for
personal injury or property damage arising out of or caused by a non-Sabine alteration or
attachment, nor does Sabine assume any responsibility for damage to interconnected nonSabine equipment that may result from the normal functioning and maintenance of the Sabine
equipment.
UNDER NO CIRCUMSTANCES WILL SABINE BE LIABLE FOR ANY LOST PROFITS, LOST
SAVINGS, ANY INCIDENTAL DAMAGES OR ANY CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PRODUCT, EVEN IF SABINE HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
THESE LIMITED WARRANTIES ARE IN LIEU OF ANY AND ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR USE; PROVIDED, HOWEVER, THAT IF THE
OTHER TERMS AND CONDITIONS NECESSARY TO THE EXISTENCE OF THE EXPRESS
LIMITED WARRANTIES, AS HEREINABOVE STATED, HAVE BEEN COMPLIED WITH,
IMPLIED WARRANTIES ARE NOT DISCLAIMED DURING THE APPLICABLE ONE-YEAR
PERIOD FROM DATE OF PURCHASE OF THIS PRODUCT.
SOME STATES DO NOT ALLOW LIMITATION ON HOW LONG AN IMPLIED WARRANTY
LASTS, OR THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL
DAMAGES, SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU.
THESE LIMITED WARRANTIES GIVE YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO
HAVE OTHER RIGHTS WHICH MAY VARY FROM STATE TO STATE.
THESE LIMITED WARRANTIES ARE THE ONLY EXPRESS WARRANTIES ON THIS PRODUCT, AND NO OTHER STATEMENT, REPRESENTATION, WARRANTY OR AGREEMENT BY
ANY PERSON SHALL BE VALID OR BINDING UPON SABINE.
In the event of any modification or disclaimer of express or implied warranties, or any limitation
of remedies, contained herein conflicts with applicable law, then such modification, disclaimer or
limitation, as the case may be, shall be deemed to be modified to the extent necessary to comply
with such law.
Your remedies for breach of these warranties are limited to those remedies provided herein,
and Sabine gives this limited warranty only with respect to equipment purchased in the United
States of America.
INSTRUCTIONS — WARRANTY REGISTRATION
• Mail the completed WARRANTY REGISTRATION CARD to:
SABINE, INC.
13301 HIGHWAY 441
ALACHUA, FL 32615-8544
• Or, register online at www.Sabine.com
IMPORTANT: Be sure to keep the PROOF OF PURCHASE. In the event warranty service is
required during the warranty period, you will need this document. There will be no identification
card issued by Sabine, Inc.
IMPORTANCE OF WARRANTY REGISTRATION & NOTIFICATION OF ADDRESS CHANGE:
a. Should notification become necessary for any condition that may require correction, the
REGISTRATION CARD will help ensure that you are contacted and properly notified.
b. Notice of address changes — If you move from the address shown on the WARRANTY
REGISTRATION CARD, you should notify Sabine of the change of address so as to facilitate
your receipt of any bulletins or other forms of notification which may become necessary in
connection with any condition that may require dissemination of information or correction.
You may contact Sabine directly by telephoning (386) 418-2000.
Please have the Sabine product name and serial number available when communicating with
Sabine Customer Service.
© 2005 Sabine, Inc.
THIS LIMITED WARRANTY VALID ONLY WHEN PURCHASED AND REGISTERED IN THE
UNITED STATES OR CANADA. ALL EXPORTED PRODUCTS ARE SUBJECT TO WARRANTY AND SERVICES TO BE SPECIFIED AND PROVIDED BY THE AUTHORIZED
DISTRIBUTOR FOR EACH COUNTRY.
LIT-FBX1200/2400-OP-EN-050817.pmd - rr
11
Register your FBX equipment
online at Sabine.com
Sabine, Inc. • 13301 NW US Highway 441 • Alachua, Florida 32615-8544 USA • Phone: (386) 418-2000 • Fax: (386) 418-2001
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