2. WHAT CAUSES FEEDBACK? | PANIC |
If unexpected feedback starts occurring during a performance, | |
pressing the PANIC button can help. As long as the button is | |
kept pressed (for a maximum of 1 second), your FBQ2496 | |
rapidly searches for feedback frequencies and suppresses | |
them. | |
SPEECH | |
Pressing the SPEECH button increases the sensitivity of | |
feedback suppression; the FBQ2496 recognizes critical | |
frequencies sooner and deploys a filter that cuts in | |
appropriately. | |
Unlike with feedback caused by a distorting guitar, human | |
speech seldom produces signals that can mistakenly be | |
identified as feedback. Therefore, this mode is ideal for | |
situations in which only speech is being transmitted. Therefore, | |
your P.A. system will be substantially louder. | |
Fig. 2.1: How a feedback loop is created | FREEZE |
Once a particularly good FBQ2496 setting is achieved, you | |
A feedback loop is created when a microphone signal is first | can keep this setting by pressing the FREEZE button. All |
Single-Shot and automatic filters are kept at their settings | |
reproduced on an amplifier, and is then picked up again by the | |
until you press FREEZE again. | |
same microphone (with the same phasing). Then, it is amplified | |
FILTER LIFT | |
and reproduced again. This feedback loop may, under certain | |
The so-called “Filter Lifting Time” informs you about how | |
circumstances, keep on occurring and could escalate out of control. | |
long an adjusted automatic filter can remain inactive before | |
With P.A. applications, there are two major types of setups in | |
its values are reset again. You can set this time by first briefly | |
which feedback can occur: | |
pressing the FILTER LIFT button and then turning the wheel. | |
s Front mix (also called F.O.H. = “front of house”) refers to the | |
The following time lengths are available: 0 min, 1 min, | |
mix being created when a signal from a mixing console is | 5 min, 10 min, 30 min, 60 min. |
( | ||||
0 | left | |||
10 | 1 | right | ||
2 | stereo (left and right) | |||
0 | Filters 1 thru 20 can be | |||
11 | ||||
selected individually | ||||
19 | ||||
0 | None, one or several (up to | |||
12 | ||||
20) filters can be selected | ||||
20 | ||||
0 | None, one or several (up to | |||
13 | ||||
20) filters can be selected | ||||
20 | ||||
0 | 20 Hz | logarithmic | ||
14 | allocation of | |||
(Coarse adjustment) | ||||
75 | 20 kHz | frequencies | ||
0 - 15 | ||||
16 - 31 | The previously set coarse | |||
32 - 47 | ||||
mid frequency (Controller 14) | ||||
48 - 63 | ||||
(Fine adjustment) | 46 | can be fine-tuned in 8 steps. | ||
64 - 79 | ||||
All digits of one step deliver | ||||
80 - 95 | ||||
the same frequency value. | ||||
96 - 111 | ||||
112 - 127 | ||||
0 | 1/60 octave | |||
' | 15 | |||
24 | 10 octaves | |||
0 | - 36 dB | |||
# | 16 | |||
81 | + 15 dB | |||
& | 17 | 0 | off | |
1 | on | |||
0 | off | |||
1 | 1 min | |||
% ' | ! % ' | 18 | 2 | 5 min |
3 | 10 min | |||
4 | 30 min | |||
5 | 60 min | |||
19 | 0 | off | ||
1 | on | |||
! | 20 | 0 | off | |
1 | on | |||
! | $ | 21 | 0 | off |
1 | on | |||
% | 22 | 0 | off | |
1 | on |
Audio inputs | |
Connections | XLR and 1/4' TRS stereo connector |
Type | electronically balanced input |
Input impedance | approx. 20 kΩ balanced |
Nominal input level | -10 dBV / +4 dBu (adjustable) |
Max. input signal level | +20 dBu at +4 dBu nominal level, |
+6 dBV at -10 dBV nominal level | |
typically -40 dB | |
Audio outputs | |
Connections | XLR and 1/4' TRS stereo connector |
Type | balanced |
Output impedance | approx. 200 Ω balanced |
Max. output level | +20 dBu at +4 dBu nominal level, |
+6 dBV at -10 dBV nominal level | |
Bypass | |
Type | Relay, hard bypass in case of |
power outage | |
System information | |
Frequency response | <10 Hz to 44 kHz |
Dynamic range | 107 dB |
THD | 0.007 % typically @ +4 dBu, 1 kHz, |
amplification 1 | |
Crosstalk | < -100 dB @ 1 kHz |
MIDI interface | |
Type | 5-pole DIN connectors IN/OUT/THRU |
Digital processing | |
Converter | 24 Bit / 96 kHz |
Sample rate | 96 kHz |
Parametric equalizer (PEQ) | |
Type | max. 20 independent, fully |
parametric filters per channel | |
Frequency range | 20 Hz to 20 kHz |
Bandwidth | 1/60th to 10 octaves |
Possible value range | +15 to -36 dB |
Feedback Destroyer (FBQ) | |
Type | digital signal analysis for feedback |
recognition purposes | |
Filter | max. 20 digital notch filters per channel |
Frequency range | 20 Hz to 20 kHz |
Bandwidth | 1/60th octave |
Possible value range | 0 to -36 dB |
Display | |
Type | 3-digit numeric LED display |
POWER SUPPLY | |
Mains voltage | 100 - 240 V~, 50 - 60 Hz |
Power consumption | approx. 10 W |
Fuse | T 1 A H 250 V |
Mains connector | Standard receptacle |
DIMENSIONS/WEIGHT | |
Dimensions (H x W x D) | approx. 44.5 mm x 482.6 mm x 190.5 mm |
(approx. 1 ¾' x 19' x 7 ½') | |
Weight | approx. 1.9 kg (4.2 lbs) |