Extron electronic DMP 64 manual Feedback Suppressor FBS

Feedback Suppressor (FBS)

The Feedback Suppressor is used in live situations when there is an indication of feedback during live operation. Dynamic filters automatically detect feedback on a live microphone channel, and engage a set of up to 5 fixed and 15 dynamic filters to counteract frequency peaks at the detected feedback frequency. Up to 15 separate filters can be employed at any time. The 15 filters act in a FIFO (first in, first out) rotation. If all 15 filters are employed when an additional feedback frequency is detected, it overwrites the first detected feedback frequency and so on.

To avoid a new feedback frequency overwriting a previously detected one, up to five of the dynamic feedback frequencies can be placed into fixed filters. Once written into the fixed filters, the feedback frequency can only be overwritten by the user manually writing a new frequency to the filter.

The FBS dialog box has three tabs; Settings, Dynamic Filters and Fixed Filters. Global settings and view options are controlled from the Settings tab. Dynamic to fixed filter allocations are handled from the Dynamic filters tab. Filter parameters can be modified from the Fixed Filters tab.

The FBS Dialog box provides the following global buttons:

•Clear All — Clears all dynamic filter settings.

•Lock — Locks the dynamic filters to the current settings, preventing automatic updates. This temporary mode is useful while testing the system, or during the time when dynamic filters are being converted to fixed filters. When the FBS display window is closed, lock mode is automatically disengaged.

•Bypass FBS — Turns off feedback detection when engaged (button is red). Only the dynamic filters are bypassed. Fixed filters remain active.

•Set Defaults — Click once to return the FBS to default settings.

Figure 32. Feedback Suppressor

DMP 64 • Software Control 41