User manual BEHRINGER DSP1124P

[. . . ] DSP1124P Users Manual Version 1. 0 February 2001 FEEDBACK DESTROYER PRO ® www. behringer. com ENGLISH FEEDBACK DESTROYER PRO DSP1124P SAFETY INSTRUCTIONS CAUTION: To reduce the risk of electrical shock, do not remove the cover (or back). No user serviceable parts inside; refer servicing to qualified personnel. WARNING: To reduce the risk of fire or electrical shock, do not expose this appliance to rain or moisture. This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosure - voltage that may be sufficient to constitute a risk of shock. This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the accompanying literature. [. . . ] As can be seen from table 11. 3, each of the ten presets on your DSP1124P comprises 24 separate filters, which can, however, be set to different operating modes: In our example, the first nine filters of the selected preset are set to Single-Shot mode (SI, see chapter 6. 3). This mode is designed to detect feedback frequencies at fixed resonance values, and to suppress them consistently. So, these filters cannot be unlocked (status LO (locked)). Their bandwidth and gain reduction can be adapted if required, however, the frequency setting remains the same. In our example, the DSP1124P is used to prevent nine fixed frequencies from making trouble. The three remaining filters (all set to Auto mode AU, see chapter 6. 3) are used to detect and suppress new feedback frequencies, which can be produced, e. g. when the singer moves around the stage with the vocal mic in his/her hand. Since the DSP1124P can by no means know whether or not the risk of feedback has been eliminated (e. g. when the singer moves to another position), the first AU filter of the unit locks to the detected frequency, while the remaining two AU filters are used to suppress any new trouble frequencies that may occur. Only when all AU filters have been used, will the first AU filter used (here: 10) be unlocked, so as to be able to detect new feedback frequencies. Basically, all active filters (both in AU or SI mode) are represented by flashing LEDs in the STATUS INDICATOR . When feedback has been detected and is being suppressed, the associated filter LED lights up constantly. Filters set to Parametric EQ mode (see chapter 6. 2) also have constantly lit LEDs. + 5. 1 Please read the detailed description of all operating modes (chapter 6)! 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. [. . . ] This also applies to defects caused by normal wear and tear, in particular, of faders, potentiometers, keys/buttons and similar parts. 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. [. . . ]