The feedback system discussion has been an ongoing debate for more than 20 years and as a long term practitioner of various devices to quell destructive looping (Feedback), I have experienced mixed success. Without question the best was the “SMAART JR.” that was available with my QU16: unfortunately the license expense was not acceptable for A&H to continue deploying this very simple, effective protocol. This is what I know;
1) Filtering out obtrusive portions of the sonic field is in of itself a destructive process. Any way you cut it there is a direct relationship between the number of filters set and the amount of sonic field that is erased!
2) The SMAART protocol is based on establishing a max of 4 customized PEQ filters. Beyond this application, external re-arrangements of stage monitoring and speaker stacks will need to be made.
3) One of the prime culprits is un-attended (open) mics and to that end various automated features to kill open mics are available with an SQ5.
There is a pragmatical reality of dealing with the ultra important initial placement of wedges, speaker stacks and mics. An in depth investment of time studying the various elements involved in room acoustical awareness and related sonic source placement factors is the best answer, not massive filtering!
Hugh