AFS224 (discontinued)

Advanced Feedback Suppression® Processor

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The AFS 224 Advanced Feedback Suppression processor was designed to provide state-of-the art feedback elimination processing, while maintaining a simple and intuitive control interface. From the powerful DSP module to the no-nonsense user interface, the AFS 224 provides all the processing and control necessary for both installation and live use. The AFS 224 is an absolute must for any live sound application.

Ten and twelve filter feedback elimination processors have become the de facto standard, but the engineering staff at dbx have never been quite content residing in the neighborhood of the status quo. So, to raise the bar once again, they went out and developed a dedicated feedback suppression processor that offers up to 24 filters per channel with filter Qs up to 1/80 of an octave. To achieve these staggering numbers dbx utilized their patent-pending AFS technology that had previously only been available in the upper echelon line of products and made it available in this stand-alone processor, which takes all of the guesswork out of feedback removal. In addition to the plethora of feedback suppression filters available, the AFS 224 also offers selectable modes, live filter lift, and types of filtration, which are all readily available via the intuitive user interface front panel.

Recommended for: Portable, Tour.


  • dbx's Patent-pending (Advanced Feedback Suppression) AFS™ technology
  • 24 Programmable Filters per Channel
  • Stereo or Dual Independent Channel Processing
  • Live and Fixed Filter Modes
  • Selectable Filter Lift Times
  • Application-specific filter types include: Speech and Music Low, Med and High
  • Input channel Metering
  • 24 LED per Channel Filter Metering
  • XLR and TRS Inputs and Outputs


  Version Language Size Uploaded
file type icon AFS224 CAD drawing front
en updated: Sep 2023
  en  185 KB Sep 2023
file type icon AFS224 CAD drawing rear
en updated: Sep 2023
  en  186 KB Sep 2023
file type icon AFS224 Cut Sheet-English
en updated: Sep 2023
  en  92.2 KB Sep 2023
file type icon AFS_Whitepaper.pdf
en updated: Sep 2023
  en  186 KB Sep 2023
file type icon AFS224 Owner's Manual-English
en updated: Sep 2023
  en  2.14 MB Sep 2023
file type icon AFS224 Quickstart Guide-English
en updated: Sep 2023
  en  1.41 MB Sep 2023

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Input 2 total
Input Connectors Female XLR ad 1/4" TRS
Input Type Electronically bal/unbal RF filtered
Input Impedance Bal 40k ohm, unbal 20k ohm
Max Input +20dBu
CMRR >40dB, typically >55dB @ 1kHz
Output 2 total
Output Connectors Male XLR and 1/4" TRS
Output Type Electronically bal/unbal, RF filtered
Output Impedance Balanced >120 ohm, unbalanced >60 ohm
Max Output +20dBu
A/D Converter dbx Type IV conversion system
A/D Dynamic Range >114dB, A-weighted, >112dB unweighted
Type IV Dynamic Range >119dB, A-weighted, 22kHz; BW: >117dB, unweighted, 22kHz BW
Sample Rate 48kHz
D/A Dynamic Range 112dB, A-weighted, 110dB unweighed
Dynamic Range >110dB, A-weighted, >107dB unweighted
THD+Noise 0.002% typical at +4dBu, 1kHz, 0dB input gain
Frequency Response 20Hz - 20kHz, +/-0.5dB
Interchannel Crosstalk >80dB typical
Operating Voltage 100VAC 50/60Hz; 120VAC 60Hz; 230VAC 50/60Hz
Power Consumption 9 W
Safety Agency Certifications UL 6500, IEC 60065, EN 55013, E 60065




Which dbx processor should I use to eliminate feedback problems in my system?

This depends on where the feedback problems occur and if you need additional processing. 

For monitors or Front of House, the most cost effective processor would be the dbxAFS 224 which provides 24 filters per channel. This is a stand alone two channel feedback suppressor that has no additional processes such as EQ, compression/limiting, crossovers etc.

For a combination of EQ and feedback suppression, the dbx IEQ15 or IEQ31 may suite the application best.

For smaller FOH systems that require additional processing, the DriveRack PA2 is a great choice.

For a combination of monitors and FOH (Front of House), and where additional processing is necessary, a single loud speaker management system such as the DriveRack 4800/4820, or 260 may be the best option.

AFS224 (discontinued)

Advanced Feedback Suppression® Processor