As GCumbee said, The GEQ is stereo, so both sides will share the same settings. Personally I prefer ringing out with the PEQ first (sweepable frequency and narrow Q means you can zero in on the exact frequency that is feeding back rather than hoping the ringing freq is of the 28 on the GEQ, and you don’t cut out a whole 1/3 of an octave when you do. This means you’re not cutting out a whole lot of the sound: 1/9th of an octave vs 1/3.) If more eq is required, then resort to the GEQ, or save the GEQ for “personal taste.” Also, if you start with the lower bands that can help with the higher bands, eg if you’ve got ringing at 400Hz and 800Hz, cutting the 400Hz first will often help with the ringing at 800Hz.