The industry standard in automatic feedback control: the FBX-2020Plus Dual Feedback Exterminator®, with 24 FBX filters (12 per channel), 20-bit digital resolution, andSabine's patented ClipGuard Adaptive Clip Level Control, which allows the FBX-2020 to accept input signals up to 27dBV without clipping, increasing the effective dynamic range to 105 dB. The FBX-2020Plus replaces the FBX-1802.

• 20-bit digital resolution
• 24 FBX filters (12 per channel)
• ClipGuard Adaptive Clip Level Control maintains optimum clip level, increases dynamic range to 105 dB, and eliminates digital clipping!
• Turbo Setup Mode — grabs feedback faster and at lower volume during setup
• Internal power supply
• More gain before feedback (6 to 9dB typical)
• Increased clarity and intelligibility
• Fast setup — less than a minute per channel
• Not just a setup tool — eliminates feedback during program, too
• Switchable filter widths: 1/10 or 1/5 octave, Constant-Q
• Filter tracking: tracks feedback when it drifts

Like all of Sabineís patented FBX Feedback Exterminators, the FBX-2020Plus does what no other audio product can do: It automatically detects and eliminates feedback without damaging your sound. The FBX precisely places an extremely narrow filter directly on the ringing feedback frequency, and the filter is placed only as deep as is necessary to eliminate the feedback. The result is more gain before feedback while preserving your clear, rich sound.

If you use your 31-band EQ just to shape your sound and let your FBX control feedback, you should expect up to 9 dB more gain and a dramatic improvement in the sound quality. Why? When you pull down a graphic EQ slider to chase feedback, you also pull out a big chunk of your sound. FBX constant-Q filters are 10 times narrower than graphic EQ filters, and FBX filters are placed exactly on the ringing feedback, with 1 Hz resolution, all in less than a second (typical) ó an impossible task for a graphic EQ. Narrow filters and precise placement mean more gain and more clarity. It's just that simple.

The FBX-2020Plus is a truly adaptive audio product. ClipGuard is always there to maintain the optimum dynamic range, and the FBX algorithm clearly distinguishes music and speech from feedback. This makes the FBX more than just a set-up tool — it controls feedback for the duration of the performance or the entire life of the installation, all without needing any further adjustment.

The inside story on FBX filters
FBX filters come in two flavors: Fixed and Dynamic. Both filters are placed the same way: Feedback is detected and the filter is placed just deep enough to eliminate it. The difference comes after the filter is placed. Fixed filters remain on the initially detected feedback tone — they do not move. These filters provide the initial maximum gain before feedback and are set automatically during setup. Dynamic filters can release and move to new feedback frequencies and are for adaptive feedback control during the performance. Factory default is 9 fixed and 3 dynamic, but this is easily changed using front panel controls.

Click here for everything you need to know about feedback and feedback control.