7. WORKING WITH PRESETS.... 15
7.1 7.2 7.3 7.4 7.5 Recalling Presets.... Selecting the filter operating mode... Editing filter parameters.... Storing presets.... Restoring the factory presets.... 16
8. PROBLEMS DO HAVE A CAUSE.... 17 9. MIDI CONTROL.... 17 10.INSTALLATION.... 18
10.1 Audio connections.... 18 10.2 MIDI connections.... 20

11.APPENDIX..... 20

11.1 Frequency chart.... 20 11.2 Preset table..... 21 11.3 MIDI implementation.... 22
12.SPECIFICATIONS..... 23 13.WARRANTY..... 24

1. INTRODUCTION

Thank you very much for expressing your confidence in BEHRINGER products by purchasing the FEEDBACK DESTROYER PRO DSP1124P. With the FEEDBACK DESTROYER PRO you have acquired a highly useful device for the control of sound reinforcement systems, which will enable you to focus your attention on what is essential: your music. The fully featured DSP1124P not only suppresses feedback but also incorporates a wealth of additional functions in one single unit. Its 24 separate filters can be edited in all parameters, and automatically detect and suppress feedback frequencies. With its pro-level internal processing circuitry, the unit can also be used as a high-end equalizer for stage and studio applications. The MIDI interface allows for integrating the DSP1124P into any MIDI system, and the open system architecture enables you to update the system software whenever you want. In short: the DSP1124P will be your reliable workhorse over many years to come.
This manual first describes the terminology used, so that you can fully understand the FEEDBACK DESTROYER PRO and its functions. Please read the manual carefully and keep it for future reference.

1.1 The design concept

The philosophy behind BEHRINGER products guarantees a no-compromise circuit design and employs the best choice of components. A 24-bit DSP is used as the heart of the FEEDBACK DESTROYER PRO, which belongs to the best components available owing to its outstanding specifications and excellent sonic characteristics. What is more, high-quality 24-bit A/D and D/A converters ensure the accurate processing of all signals. Additionally, the FEEDBACK DESTROYER uses high-quality resistors and capacitors with very tight tolerances, high-grade switches, and further selected components. The FEEDBACK DESTROYER PRO employs SMD technology (Surface Mounted Device). These subminiature components known from aerospace technology allow for an extreme packing density and improve the units reliability even further. Additionally, the DSP1124P was manufactured in compliance with an ISO9000 certified management system.

1.2 Before you begin

Your FEEDBACK DESTROYER PRO was carefully packed in the factory and the packaging was designed to protect the unit from rough handling. Nevertheless, we recommend that you carefully examine the packaging and its contents for any signs of physical damage, which may have occurred in transit.
If the unit is damaged, please do not return it to us, but notify your dealer and the shipping company immediately, otherwise claims for damage or replacement may not be granted. Shipping claims must be made by the consignee.
The BEHRINGER FEEDBACK DESTROYER PRO requires one standard 19" unit of rack space. Please allow at least an additional 4" depth for the connectors on the back panel. Be sure that there is enough space around the unit for cooling and please do not place the FEEDBACK DESTROYER PRO on high-temperature devices such as power amplifiers, etc. to avoid overheating.
Before you connect your FEEDBACK DESTROYER PRO to the mains, please make sure that your local voltage matches the voltage required by the unit:
The fuse holder on the female mains connector has 3 triangular markings, with two of these triangles opposing each other. The FEEDBACK DESTROYER PRO is set to the operating voltage printed next to these markers and can be set to another voltage by turning the fuse holder by 180. CAUTION: This instruction does not apply to export models exclusively designed, e.g. for 115-V operation! Please use the enclosed power cord to connect the unit to the mains. The cord complies with all applicable safety standards.
FEEDBACK DESTROYER PRO DSP1124P Please note that all units must be grounded properly. For your own safety, you should never remove any ground connectors from electrical devices or power cords or render them inoperative.
As a standard, the BEHRINGER FEEDBACK DESTROYER PRO is equipped with electronically servo-balanced inputs and outputs. The circuit design features automatic hum and noise reduction for balanced signals and thus allows for trouble-free operation, even at high operating levels. Externally induced mains hum, etc. will be effectively suppressed. The automatic servo-function recognizes the presence of unbalanced connectors and adjusts the nominal level internally to avoid level differences between the input and output signals (6-dB correction). The MIDI interfaces IN, OUT, and THRU are on standardized DIN connectors. Data are transmitted via potential-free opto couplers.
Background: How is feedback produced?
A feedback loop is produced when a microphone signal is reproduced by an amplification system and is subsequently picked up again (with identical phase) by the microphone. If this happens repeatedly, such a feedback loop can become ever more persistent.
Fig. 1.1: How a feedback loop is produced
1.3.1 Background: front of house mix (FOH) There are two main sections in any sound reinforcement system, which are liable to produce feedback: the first section is the so-called front of house mix (FOH), i.e. the public address mix, which is reproduced by one or several amplifiers plus several loudspeakers directed at the audience. 1.3.2 Background: monitor mix The monitor mix, which is often derived from the same console, feeds one or several stage-mount monitor speakers. Unlike FOH systems, stage monitors are used to provide the individual musicians with a monitor signal, because it is often difficult to hear oneself or each other on the stage, which can be due to the high volume levels produced by the FOH systems, or to different volume levels of the stage-mount instruments and amplifiers. It is therefore not unusual to give each musician his or her own monitor speaker, which is why there are usually several monitor speakers placed along the stage. This is the only way to provide each musician with a directed and focused monitor signal. In an ideal situation, each monitor provides a specific mix, comprising e.g. vocals, drums and keyboards, for each individual musician on the stage. Unfortunately, it is anything but easy to find perfect positions for the various stage monitors, because the distance between speaker and microphone must be kept very short, which in turn increases the risk of feedback.

Owing to its 2-channel design, the DSP1124P is the perfect tool for application in two separate monitor paths. However, if you need to protect four monitors against feedback, we recommend that you use a second DSP1124P. If possible, all monitor paths should be set pre-fader, as this leaves the monitor mix unaffected from any changes made to the FOH mix.
Fig. 2.1: Using the DSP1124P in the monitor sends
Using the FEEDBACK DESTROYER PRO in the FOH mix
Since you want to make sure that deliberately produced feedback signals, such as guitar feedback, are not eliminated, you should try inserting the DSP1124P into those channels that are susceptible to feedback. For example, you could process a vocal microphone that is liable to produce feedback by connecting the DSP1124P to the insert points of the respective channel.
Fig. 2.2: Using the DSP1124P for specific mics (connecting the FEEDBACK DESTROYER PRO in either channel or sub-group inserts)
When processing a microphone signal with the DSP1124P and a compressor inserted into the same channel insert point, the FEEDBACK DESTROYER PRO should always be used pre-compressor: in this way, the signal is taken at the insert jack, passes the DSP1124P, then the compressor, and is finally routed back to the insert jack.
Ideally, your mixer has sub-groups with dedicated insert points to connect the DSP1124P! Route all channels that are susceptible to feedback (e.g. all vocal mics) to one sub-group. While the other signals (e.g. line level signals, low-level instrumental mics) pass unaffected, all critical microphone channels are monitored by the DSP1124P. If your mixer has no sub-group inserts, we recommend that you connect the DSP1124P as follows: connect the sub-group output to one input on the DSP1124P, and the corresponding output to a free line input of a mixing console channel or one of the Aux Return inputs on the console. As long as ENGINE L and ENGINE R are not linked, you would even have the second channel of your FEEDBACK DESTROYER PRO free for other applications (e.g. channel inserts). 2. APPLICATIONS 9
2.4 Using the FEEDBACK DESTROYER PRO in a studio environment
With its highly flexible configuration the DSP1124P also delivers good results in a professional studio or home recording environment, as it provides a maximum of 12 fully parametric equalizers per channel in Parametric EQ mode. Thus, you can realize any application ranging from slight processing to the total manipulation of music signals. For example, you can use the DSP1124P as an equalizer for your studio monitors or to enhance the EQs in your mixing console, as these are often only semi-parametric.

3. A FEW QUICK STEPS TO ELIMINATE FEEDBACK
Irrespective of whether you need the DSP1124P to protect the FOH or the monitor mix against feedback, the following procedure is always the same and should be done before the concert, so as to eliminate basic feedback problems right before the show begins: s Check the setting of the OPERATING LEVEL switch on the rear of the unit. For most P.A. systems, this switch should be set to +4 dB. In doubt, please consult the users manual of your mixing console. Always make sure that the audio signal levels are set correctly (see control element ). s Switch on the unit, and use the JOG WHEEL (rotary control) to select preset 1. The preset table (see table 11.3) lists the various DSP1124P presets available. s Using the DSP1124P in the monitor path: Turn up the Aux Send or Mon. controls in the first mic channel, until the microphone starts to produce feedback. If more than one monitor paths is being used, this procedure must be done separately for each path. Repeat for each susceptible mic channel. s Using the DSP1124P on channel/sub-group inserts: Deliberately induce feedback by setting the channel/ sub-group faders to 0 dB and raising the gain controls for the individual microphones in turn. In either case, the FEEDBACK DESTROYER PRO will suppress feedback as soon as it is producedthe corresponding LED will stop flashing and stay lit. The various edit options available are described in chapter 7. But dont let us do the second step before the first:

4. CONTROL ELEMENTS

The BEHRINGER FEEDBACK DESTROYER PRO is equipped with ten parameter keys, one JOG WHEEL (rotary control) and a numeric LED DISPLAY. By means of an 8-segment LED meter, each of the two fully independent channels can be monitored. Each of the 24 filters has one LED assigned to it, which informs about the status of the filter.
Fig. 4.1: Display section of the FEEDBACK DESTROYER PRO
The LED METER is used to monitor the output level. Each channel has eight LEDs assigned to it. When the Clip LED lights up frequently, this warns you of digital distortion. If the DSP1124P is set to Total Bypass mode (see ), the level meter reads the input level. Please always use appropriate level settings, as this is essential for successful feedback elimination. The DSP1124P features 24 filters, i.e. 12 filters per channel. These filters can be monitored conveniently with the STATUS INDICATOR next to the DISPLAY. 12 LEDs inform you about the status of the filters on each channel (left/right). A constantly lit LED signals the following conditions: 4. A FEW QUICK STEPS TO ELIMINATE FEEDBACK

FEEDBACK DESTROYER PRO DSP1124P s A filter has been set, i.e. it is already suppressing feedback; or: s A filter is set to Parametric EQ mode (gain 0 dB). Cyclically flashing LEDs signal that a filter is searching feedback frequencies in Single-Shot or Auto mode (see chapters 5 and 6.3). Inactive filters (OF) and filters in Parametric EQ mode (see 6.2), with a gain setting of 0 dB, are indicated by unlit LEDs.
The LED DISPLAY consists of a clearly visible, two-digit numeric display. After power-up, it reads the number of the last preset used. Additionally, the LED-DISPLAY shows the absolute values of the parameters that are being edited. The INDICATORS to the right of the DISPLAY (Hz, kHz, 1/60 and dB) light up when you edit the associated parameters in Edit mode. For example, when you raise the level of a filter, the dB indicator lights up.
Fig. 4.2: Function keys and JOG WHEEL
With the JOG WHEEL, a continuous rotary control, you can freely edit the selected parameters. Turn the wheel clockwise to increase the values, or counterclockwise to reduce them. With the FILTER SELECT key activated, you can use the JOG WHEEL to select one of the 12 filters per channel. Subsequently, you can edit the filters. The FILTER MODE key gives you access to the four operating modes for the individual filters: Off mode (OF), Parametric EQ (PA), Single-Shot mode (SI) and Auto mode (AU). Please read chapter 6 OPERATING MODES OF THE DSP1124P. Pressing the FILTER MODE and GAIN keys simultaneously allows you to adjust the sensitivity of the feedback suppression trigger circuit. The setting range is from -3 through -9 dB and can be adjusted with the JOG WHEEL. The default value is -6 dB, as this setting usually delivers the best results. Use the ENGINE L key to select the left audio channel. Use the ENGINE R key to select the right audio channel. If you wish to process both channels at the same time (Couple mode), press both ENGINE keys together. In Couple mode both ENGINE LEDs light up. Whenever you edit one of the two audio channels and then switch to Couple mode, the parameters of the active channel will be copied to the other, i.e. if you press ENGINEL before ENGINER, left will be copied to right. through refer to Parametric EQ mode only (see chapters 5 and 7.3).
Press the FREQUENCY key to select the frequency you wish to process. The adjustable frequency range is from 20 Hz through 20 kHz, which are split up by the DSP1124P into the 31 standard ISO values of a graphic equalizer (see chapter 11.1 in the appendix). The FINE key allows you to fine tune the standard ISO frequencies (in 1/60-octave steps), within a tuning range of 1/3 octave (-9/60 to +10/60). BANDWIDTH determines the filter bandwidth (Q factor) of the selected filter. This adjustable filter quality ranges from 1/60 octave to 2 octaves (120/60 octave). 4. CONTROL ELEMENTS 11

The GAIN key sets the desired boost/cut of the selected filter in dB (+16 dB/-48 dB). The IN/OUT key allows for optional bypassing of the parametric filters or all filters. By shortly pressing the IN/OUT key, only the Parametric EQ filters will be deactivated, and the green LED goes out. Hold down the key for about two seconds to deactivate all filters. This Total Bypass mode is indicated by the cyclic flashing of the green LED. Another short IN/OUT key press reactivates all filters. Additionally, the LED flashes when relevant MIDI data are being received. If the control LED of the IN/OUT key flashes, all functions (including all automatic filters used for feedback suppression) are disabled (Total Bypass). In all other modes, at least the Single-Shot and Auto filters are active (Bypass). Please use the Total Bypass function only with caution, because the deactivation of the filters possibly unlocks suppressed feedback. Any modifications made to a preset can be stored with the STORE key, in accordance with the number shown by the DISPLAY. Ten presets are available on the DSP1124P. Press the IN/OUT and STORE keys simultaneously to enter MIDI Setup mode. Use the POWER switch to switch the FEEDBACK DESTROYER PRO on or off.
Fig. 4.3: Rear panel connectors and control elements
Use the OPERATING LEVEL switch to change from home recording level (-10 dBV) to studio level (+4 dBu), and vice versa. The level meters are adapted automatically to the selected nominal level, so that the FEEDBACK DESTROYER PRO will always work in its optimum operating range. These are the balanced INPUTS of the DSP1124P, which are on 1/4" TRS and XLR connectors. The two OUTPUTS of your FEEDBACK DESTROYER PRO are also on balanced 1/4" TRS and XLR connectors. SERIAL NUMBER. Please take the time to fill in and return the warranty card within 14 days after the date of purchase, so as to benefit from our extended warranty. Or use our online registration option available on the World Wide Web at www.behringer.com. The DSP1124P features a complete set of MIDI functions. In addition to the usual MIDI IN and MIDI OUT ports, the MIDI THRU allows you to loop through MIDI data. FUSE HOLDER / VOLTAGE SELECTOR. Please make sure that your local voltage matches the voltage indicated on the unit, before you attempt to connect and operate the unit. Blown fuses may only be replaced by fuses of the same type and rating. Some models allow for inserting the fuse holder in two different positions, in order to switch over from 230-V to 115-V operation, and vice versa. Please note that for 115-V operation outside Europe, you need to use a fuse of a higher rating (see chapter 1.2). Use the enclosed power cord to connect the unit to the mains.

Priming the DSP1124P for P.A. and monitor applications
With the DSP1124P you can improve the protection against feedback even before the show begins, by tuning in your sound reinforcement system. We already dealt with this in chapter 3. But now its not about using a preset, but about how to determine in which modes the filters are used: Set some of the filters to Single-Shot mode (see ). First, lets take a look at the monitor path: Open all microphone channels, turn up the Aux Send controls on all channels you wish to route to the monitor mix, then slowly move up the monitor master faders. For the front mix do as follows: Slowly move up the channel and master faders. In both cases, the first feedback frequencies can be heard after some time. Without the FEEDBACK DESTROYER PRO you could not increase the volume level of your system any further. With the DSP1124P, however, you can considerably enhance the system headroom! Let the Single-Shot filters on the DSP1124P suppress feedback as it occurs. Then cut back the volume to the level required for the show. In this way, you can be sure that there is enough system headroom should it become necessary to raise the volume level during the concert. Experience has shown that musicians want to have the volume of their instrument increased on the monitor as the concert goes on. With the FEEDBACK DESTROYERPRO you can turn up the volume without having to fear feedback problems. When the show begins you should set several filters to Auto mode, in order to suppress feedback produced by moving (vocal) microphones. More information on Auto mode can be found in chapters 5 and 6.3.
6. OPERATING MODES OF THE DSP1124P
The individual filters on the BEHRINGER FEEDBACK DESTROYER PRO can operate in four different modes (see ). An additional mode called Locked mode will be described specifically. Basically, each of the 2 x 12 filters on the DSP1124P can be set to any of the four operating modes. To meet more complex requirements with regard to flexible signal processing, these modes can be combined in a program and stored in a preset.

6.1 Off mode OF

In Off mode, the corresponding filter is deactivated and can be activated by selecting one of the modes described below.

6.2 Manual filters (PA) / parametric equalizer
To raise or lower specific frequencies in level, you can select these frequencies directly by setting the manual filters to Parametric EQ mode. Each filter has the functionality of a fully parametric EQ, i.e. you can set the center frequency (FREQUENCY key ), the bandwidth (BANDWIDTH key ) and the amount of boost/cut (in dB) using the GAIN key.
6.3 Automatic filters (SI and AU)
Automatic filters operate in two modes: Single-Shot (SI) and Auto mode (AU). In order to find a feedback frequency, the FEEDBACK DESTROYER PRO divides the entire frequency band into 1/60 octave steps (20 Hz to 20 kHz) and determines the respective level of these individual bands. The unit then compares this value to the level of the entire signal. The difference between these levels determines whether a filter is set or not. The FEEDBACK DESTROYER PRO gives you the unique possibility of adapting this parameter according to your own needs. You can edit the feedback sensitivity (i.e. the difference value) within a range from -3 to -9 dB, in 1-dB steps: Simultaneously press the FILTER MODE and GAIN keys, then use the JOG WHEEL to select a value. The standard value for this parameter is -6 dB, which provides for an optimum detection of feedback in most applications. Example: During a pure speech transmission, the feedback sensitivity can be lowered to -9 dB. In this way, the algorithm would recognize and suppress feedback even faster. On the other hand, a higher setting, e.g. -3 dB, allows you to leave those signals unaffected which you dont want to suppress (e.g. guitar or keyboard signals). Filters in Single-Shot mode automatically analyze the music signal to detect feedback frequencies. Having detected such a frequency, the filter automatically configures its parameters to suppress feedback as efficiently as possible. As the filter is locked to the detected frequency, this mode is ideally suited to suppress feedback of constant frequency. Possible applications are fixed-position microphones (e.g. on the drums). After the filter has adjusted itself automatically, it enters a special Locked mode (see chapter 6.4), which means that although the frequency remains fixed, the width and depth of the filter are still being adapted to the feedback frequency, i.e. the width is increased as soon as the feedback frequency begins to shift, and the gain is cut if feedback prevails. The gain is not reduced to prevent feedback from recurring. All microphones that are moved during a performance (e.g. vocal mics) very often have varying feedback frequencies. This type of feedback should be suppressed in Auto mode. As in Single-Shot mode, the filter automatically selects an ideal setting for feedback suppression. However, in Auto mode the first AU filter set is unlocked to suppress new feedback. The optimum frequency is selected automatically and the filter is set to narrow-band mode, so as to influence the music signal as little as possible. If your music contains wanted feedback elements (e.g. guitar feedback), it is highly probable that these will be suppressed too in Auto mode, because it is impossible from a physical point of view to distinguish wanted from unwanted feedback. Please read chapter 2.3 to find some information on how to work around this situation.

FEEDBACK DESTROYER PRO DSP1124P To avoid inadvertent changing of filter modes, the filter mode selection takes place after about one second, which is indicated by a dot in the lower right corner of the DISPLAY. Press the FILTER MODE and GAIN keys at the same time, and use the JOG WHEEL to adjust the feedback threshold (= feedback sensitivity) within a range from -3 to -9dB.
7.3 Editing filter parameters
Remember: Your DSP1124P has ten pre-configured user presets, each comprising 12 filters per channel. Each individual filter can be selected in any of the four operating modes! However, the Locked mode cannot be selected directly: when a filter which was selected as Single-Shot detects a feedback frequency, the filter is automatically set and locked, i.e. the filter is locked to the problem frequency and keeps an eye on it. In Single-Shot and Auto modes, the filter parameter cannot be edited but only displayed. Editing can be done in Parametric EQ mode only:
To change filter settings manually, the respective filter must be set to Parametric EQ mode. Press and keep the FILTER MODE key for about one second. Now, you can adapt the frequency after pressing FREQUENCY. Depending on the preset frequency, either the Hz or the kHz indicator to the right of the DISPLAY lights up. For example, when the filter is set to 160 Hz, the numeric DISPLAY will read the value and the Hz indicator lights up. To raise the frequency to 2,700 Hz, turn the JOG WHEEL clockwise until the ISO frequency (2.5 kHz; see Tab. 11.2) next to this value appears in the DISPLAY and the kHz indicator lights up. The FINE key allows you to fine tune the chosen standard ISO frequency within a tuning range of 1/3 octave (in 1/60-octave steps). The mathematical proportion between the displayed value and the absolute frequency, as well as a guide to find the desired frequency quickly, are listed in the appendix (chapter 11.1 frequency chart). The bandwidth of the filter (quality) can be adjusted by selecting the BANDWIDTH key. The adjustable bandwidth ranges from 2 octaves down to 1/60 octave. By pressing the GAIN key, it is possible to set the desired boost or cut of the selected frequency. A + or - signals that the level is being increased or decreased respectively.

Filters in Single-Shot or Auto mode can be transformed into parametric filters with the same frequency, quality and 0 dB gain by pressing the FILTER MODE key for about one second. Only then will it be possible to edit the filter parameters.

7.4 Storing presets

Whenever you edit a preset, the LED in the STORE key starts flashing. Basically, all edits in Parametric EQ mode and the filter deactivation in Off mode can be stored. Filters in Single-Shot or Auto mode adjust and store their parameters automatically. However, these data will get lost when you switch off the unit. To avoid that, please write the edited setting to a preset before you switch the DSP1124P off: Press the STORE key once, so that the DISPLAY starts flashing. If you wish to preserve the original preset, use the JOG WHEEL to select another preset number, which can be overwritten. Then, press STORE again to save your edits to the selected preset. If you wish to overwrite the original preset, simply press the STORE key twice after editing, so as to save all edits to the same preset.
7.5 Restoring the factory presets
Press and keep the FILTER SELECT and STORE keys pressed before you switch on the FEEDBACK DESTROYER PRO. After power-up keep the switches pressed for another second. The preset numbers are counted up and the presets are reset to their original default values.
8. PROBLEMS DO HAVE A CAUSE.
Feedback is one of the major problems encountered in live P.A. applications. In a worst-case scenario every microphone signal passing an amplifier can cause feedback. Still, theres a lot you can do even before the show begins: s Place the microphones at some distance to the FOH and monitor speakers. s Make sure that the levels of the microphone channels are adjusted correctly (see users manual of your console). s Use the microphones according to their polar patterns (e.g. omnidirectional, cardioid, super-cardioid). s Poor room acoustics should be improved. Tiled walls and floors, which are highly reflective, can be covered with curtains or carpet. s Use a graphic equalizer to adapt the overall sound to the room acoustics. s To a certain degree, feedback can also be suppressed manually with a graphic EQ.

9. MIDI CONTROL

Use the MIDI key combination to select the MIDI parameters you wish to adjust. To do so, press and keep the IN/OUT and STORE keys at the same time. All parameters can be edited with the JOG WHEEL and these two keys. The MIDI menu includes six pages, which you can select by pressing the IN/OUT key (forward) and the STORE key (backward) several times. On the first page, you can select the MIDI channel. The DISPLAY reads a small c (= channel). The JOG WHEEL adjusts a channel from 1 through 16. To switch off the MIDI function, simply select 0 (displayed as -). On the second page, you can select MIDI Omni mode, i.e. the unit transmits/receives on all 16 MIDI channels. The DISPLAY reads O (= Omni). Use the JOG WHEEL to activate (1) or deactivate (0) MIDI Omni mode. The third page allows for the configuration of controller commands. On its right-hand side, the DISPLAY reads a capital C (= Controller). The JOG WHEEL selects one of the five controller modes shown below:

10. INSTALLATION

10.1 Audio connections
As a standard, the audio inputs and outputs on the BEHRINGER FEEDBACK DESTROYER PRO are fully balanced. If possible, connect the unit to other devices in a balanced configuration to allow for maximum interference immunity.

10.INSTALLATION

Fig. 10.1: Different plug types
Fig. 10.2: Wiring an insert cable
Please ensure that only qualified persons install and operate the FEEDBACK DESTROYER PRO. During installation and operation the user must have sufficient electrical contact to earth. Electrostatic charges might affect the operation of the unit.

10.2 MIDI connections

The MIDI connectors found on the rear panel are on internationally standardized 5-pin DIN jacks. You need dedicated MIDI cables to connect the FEEDBACK DESTROYER PRO to other MIDI equipment. Normally, complete cables will be purchased for this use, but you can also make your own, using a high-quality two-conductor shielded cables (e.g. microphone cable) and two rugged 180 DIN plugs: pin 2 (center) = shield, pins 4 and 5 (right and left of pin 2) = internal conductors, pins 1 and 3 (the two outer pins) are not used. MIDI cables should have a maximum length not exceeding 15 meters. MIDI IN: Receives MIDI control data. The receive channel is determined in the SETUP menu. MIDI THRU: Provides an unchanged copy of the signal received at the MIDI IN, for example, to daisy-chain several FEEDBACK DESTROYER PROs. MIDI OUT: Transmits MIDI data to a connected computer or other FEEDBACKDESTROYERPROs. Transmitted are program data as well as status information for signal processing.

11. APPENDIX

11.1 Frequency chart
Display ,20 ,25 ,32 ,40 ,50 ,63 ,80 1,00 1,25 1,60 2,0 2,5 3,2 4,0 5,0 6,3 8,0 10,0 12,5 16,Hz Hz Hz Hz Hz Hz Hz Hz Hz Hz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz -9/60 22,8 28,6 36,2 45,72,-8/28,9 36,-6/60 23,5 29,6 37,-4/30,2 38,-2/60 24,5 30,9 39,ISO 31,20000 +2/60 20,5 25,7 32,+4/26,3 33,+6/60 21,34,+8/27,6 34,+10/60 22,5 28,3 35,57 71,18000 Display ,20 ,25 ,32 ,40 ,50 ,63 ,80 1,00 1,25 1,60 2,0 2,5 3,2 4,0 5,0 6,3 8,0 10,0 12,5 16,Hz Hz Hz Hz Hz Hz Hz Hz Hz Hz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz kHz
kHz 1820 kHz 2275 kHz 2858 kHz 3618 kHz 4550 kHz 5715 kHz 7235 kHz 9100 kHz 11375 kHz 14425 kHz 18200
Tab. 11.1: Frequency chart In order to maintain a better survey only every second value is registered in the table. The adjustable values do not exactly fit into a 1/60 octave interval, because also the ISO frequencies do not perfectly fit into a physical 1/3 octave interval. Rather a linear approximation is used to specify the values. Background f1,f2,. ISO frequencies 1 third = 20/60 octave (idealized ISO interval)

Tab. 11.4: MIDI implementation chart

Parameter Name

Display Range
Midi Control Number 18 19
Control Value Range Couple Left 0.11 0.3 0,1,2 0.30 0.19 0.119 0.64 0.6 0.9 0.2

LEDs Right IN on

IN off

IN flashing

Filter Select 1.12 Filter Mode OF, PA, AU, SI Engine Frequency 20 (Hz).20 (kHz) Fine (1/60 Oct) -9.+10 Bandwidth 1.120 Gain -48.+16 Feedback Sensitivity -3.-9 Store 1.10 In/Out
Tab. 11.5: Controller functions with MIDI

12. SPECIFICATIONS

AUDIO INPUTS Connectors Type Impedance Nominal Operating Level Max. Input Level AUDIO OUTPUTS Connectors Type Impedance Max. Output Level SYSTEM SPECIFICATIONS Bandwidth Noise THD Crosstalk MIDI INTERFACE Type DIGITAL PROCESSING Converters Sampling Rate DISPLAY Type POWER SUPPLY Mains Voltages
XLR and 1/4" TRS RF filtered, servo-balanced input 60 kOhms balanced, 30 kOhms unbalanced -10 dBV to +4dBu (switchable) +16 dBu at +4 dB nominal level, +2 dBV at -10 dBV nominal level XLR and 1/4" TRS Electronically servo-balanced output stage 60 Ohms balanced, 30 Ohms unbalanced +16 dBu at +4 dB nominal level, +2 dBV at -10 dBV nominal level 20Hz to 20kHz, -3dB > 94dB, unweighted, 20Hz to 20kHz 0.0075 % typ. @ +4dBu, 1kHz, Gain 1 < -76dB 5-Pin-DIN-Socket IN / OUT / THRU 24-bit Sigma-Delta, 64/128-times Oversampling 46,875kHz 2 -digit numeric LED-Display USA/Canada 120 V ~, 60Hz U.K./Australia 240 V ~, 50Hz Europe 230 V ~, 50Hz General Export Model 100 - 120 V ~, 200 - 240 V ~, 50 - 60Hz approx. 15 Watts max. 100 - 120 V ~: T 200 mA H 200 - 240 V ~: T 100 mA H Standard IEC receptacle approx. 1 3/4" (44.5 mm) x 19" (482.6 mm) x 7 1/2" (190.5 mm) approx. 2 kg approx. 3 kg
Power Consumption Fuse Mains Connection PHYSICAL Dimensions (H x W x D) Net Weight Shipping Weight
BEHRINGER is constantly striving to maintain the highest professional standards. As a result of these efforts, modifications may be made from time to time to existing products without prior notice. Specifications and appearance may differ from those listed or illustrated.

12.SPECIFICATIONS

13. WARRANTY
1 WARRANTY CARD/ONLINE REGISTRATION To be protected by the extended warranty, the buyer must complete and return the enclosed warranty card within 14 days of the date of purchase to BEHRINGER Spezielle Studiotechnik GmbH, in accordance with the conditions stipulated in 3. Failure to return the card in due time (date as per postmark) will void any extended warranty claims. Based on the conditions herein, the buyer may also choose to use the online registration option via the Internet (www.behringer.com or www.behringer.de). 2 WARRANTY 1. BEHRINGER (BEHRINGER Spezielle Studiotechnik GmbH including all BEHRINGER subsidiaries listed on the enclosed page, except BEHRINGER Japan) warrants the mechanical and electronic components of this product to be free of defects in material and workmanship for a period of one (1) year from the original date of purchase, in accordance with the warranty regulations described below. If the product shows any defects within the specified warranty period that are not due to normal wear and tear and/or improper handling by the user, BEHRINGER shall, at its sole discretion, either repair or replace the product. 2. If the warranty claim proves to be justified, the product will be returned to the user freight prepaid. 3. Warranty claims other than those indicated above are expressly excluded. 3 RETURN AUTHORIZATION NUMBER 1. To obtain warranty service, the buyer (or his authorized dealer) must call BEHRINGER (see enclosed list) during normal business hours BEFORE returning the product. All inquiries must be accompanied by a description of the problem. BEHRINGER will then issue a return authorization number. 2. Subsequently, the product must be returned in its original shipping carton, together with the return authorization number to the address indicated by BEHRINGER. 3. Shipments without freight prepaid will not be accepted. 4 WARRANTY REGULATIONS 1. Warranty services will be furnished only if the product is accompanied by a copy of the original retail dealers invoice. Any product deemed eligible for repair or replacement by BEHRINGER under the terms of this warranty will be repaired or replaced within 30 days of receipt of the product at BEHRINGER. 2. If the product needs to be modified or adapted in order to comply with applicable technical or safety standards on a national or local level, in any country which is not the country for which the product was originally developed and manufactured, this modification/adaptation shall not be considered a defect in materials or workmanship. The warranty does not cover any such modification/adaptation, irrespective of whether it was carried out properly or not. Under the terms of this warranty, BEHRINGER shall not be held responsible for any cost resulting from such a modification/adaptation. 3. Free inspections and maintenance/repair work are expressly excluded from this warranty, in particular, if caused by improper handling of the product by the user. This also applies to defects caused by normal wear and tear, in particular, of faders, potentiometers, keys/buttons and similar parts. 4. Damages/defects caused by the following conditions are not covered by this warranty: s misuse, neglect or failure to operate the unit in compliance with the instructions given in BEHRINGER user or service manuals. s connection or operation of the unit in any way that does not comply with the technical or safety regulations applicable in the country where the product is used. s damages/defects caused by force majeure or any other condition that is beyond the control of BEHRINGER. 5. Any repair or opening of the unit carried out by unauthorized personnel (user included) will void the warranty. 6. If an inspection of the product by BEHRINGER shows that the defect in question is not covered by the warranty, the inspection costs are payable by the customer. 7. Products which do not meet the terms of this warranty will be repaired exclusively at the buyers expense. BEHRINGER will inform the buyer of any such circumstance. If the buyer fails to submit a written repair order within 6 weeks after notification, BEHRINGER will return the unit C.O.D. with a separate invoice for freight and packing. Such costs will also be invoiced separately when the buyer has sent in a written repair order. 5 WARRANTY TRANSFERABILITY This warranty is extended exclusively to the original buyer (customer of retail dealer) and is not transferable to anyone who may subsequently purchase this product. No other person (retail dealer, etc.) shall be entitled to give any warranty promise on behalf of BEHRINGER. 6 CLAIM FOR DAMAGES Failure of BEHRINGER to provide proper warranty service shall not entitle the buyer to claim (consequential) damages. In no event shall the liability of BEHRINGER exceed the invoiced value of the product. 7 OTHER WARRANTY RIGHTS AND NATIONAL LAW 1. This warranty does not exclude or limit the buyers statutory rights provided by national law, in particular, any such rights against the seller that arise from a legally effective purchase contract. 2. The warranty regulations mentioned herein are applicable unless they constitute an infringement of national warranty law.

DSP1124P

Technical Specifications

Version 1.0 June 2001

FEEDBACK DESTROYER PRO

www.behringer.com

ENGLISH

FEEDBACK DESTROYER PRO DSP1124P
24-Bit Dual Engine Digital Feedback Destroyer/Parametric EQ Model DSP1124P
I Ultra-high performance 2-channel digital Feedback Destroyer/parametric EQ powered by a 24-bit high-speed DSP I 24-bit A/D and D/A converters with 64/128 times oversampling for ultra-high headroom and resolution I Automatically and intelligently searches out and destroys up to 12 frequencies per channel I 24 fully programmable parametric filters that can be set manually or via MIDI
I Set-and-forget default setting enables immediate and super-easy Feedback Destroyer performance
I Single-Shot mode automatically searches and destroys feedback and locks the filter until you reset it manually I Auto mode continuously monitors the mix, resetting programmed filters automatically
I Manual mode allows for setting up to 2 x 12 fully parametric filters including frequency, bandwidth and gain I Single-Shot, Auto and Manual modes are assignable for each filter
I Free FEEDBACK DESTROYER design software allows for total remote control via PC (download at www.behringer.com) I Two digital processing engines give you independent or coupled functions on left and right channels
I Servo-balanced inputs and outputs on gold plated XLR and 1/4" TRS connectors for high signal integrity I Internal 24-bit processing with professional 46 kHz sampling rate
I Full MIDI capability and user preset memories to store programs for instant recall
I Accurate eight-segment LED level meters simplify level setting for optimum performance I Future-proof software-upgradeable architecture
I High-quality components and exceptionally rugged construction ensure long life and durability I Internal power supply design for professional application I Manufactured under ISO9000 certified management system 2

,52 "2

SPECIFICATIONS
AUDIO INPUTS Connectors Type Impedance Nominal Operating Level Max. Input Level AUDIO OUTPUTS Connectors Type Impedance Max. Output Level SYSTEM SPECIFICATIONS Bandwidth Noise THD Crosstalk MIDI INTERFACE Type DIGITAL PROCESSING Converters Sampling Rate DISPLAY Type POWER SUPPLY Mains Voltages
XLR and 1/4" TRS RF filtered, servo-balanced input 60 kOhms balanced, 30 kOhms unbalanced -10 dBV to +4dBu (switchable) +16 dBu at +4 dB nominal level, +2 dBV at -10 dBV nominal level
XLR and 1/4" TRS Electronically servo-balanced output stage 60 Ohms balanced, 30 Ohms unbalanced +16 dBu at +4 dB nominal level, +2 dBV at -10 dBV nominal level
20 Hz to 20 kHz, -3 dB > 94 dB, unweighted, 20 Hz to 20 kHz 0.0075 % typ. @ +4 dBu, 1 kHz, Gain 1 < -76 dB
5-Pin-DIN-Socket IN / OUT / THRU
24-bit Sigma-Delta, 64/128-times Oversampling 46,875 kHz
2 -digit numeric LED-Display
Power Consumption Fuse Mains Connection PHYSICAL Dimensions (H x W x D) Net Weight Shipping Weight
USA/Canada 120 V ~, 60 Hz U.K./Australia 240 V ~, 50 Hz Europe 230 V ~, 50 Hz General Export Model 100 - 120 V ~, 200 - 240 V ~, 50 - 60 Hz approx. 15 Watts max. 100 - 120 V ~: T 200 mA H 200 - 240 V ~: T 100 mA H Standard IEC receptacle
approx. 1 3/4" (44.5 mm) x 19" (482.6 mm) x 7 1/2" (190.5 mm) approx. 2 kg approx. 3 kg
BEHRINGER is constantly striving to maintain the highest professional standards. As a result of these efforts, modifications may be made from time to time to existing products without prior notice. Specifications and appearance may differ from those listed or illustrated.
The information contained in this manual is subject to change without notice. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording of any kind, for any purpose, without the express written permission of BEHRINGER Spezielle Studiotechnik GmbH. BEHRINGER and FEEDBACK DESTROYER are registered trademarks. ALL RIGHTS RESERVED. 2001 BEHRINGER Spezielle Studiotechnik GmbH. BEHRINGER Spezielle Studiotechnik GmbH, Hanns-Martin-Schleyer-Str. 36-38, 47877 Willich-Mnchheide II, Germany Tel. +49 (0) / 92 06-0, Fax +49 (0) / 92 06-30