Adjusting The Low Range Resonance Of The Master Equalizer [Lowq]; Adjusting The Low-Middle Range Resonance Of The Master Equalizer [Lowmidq]; Adjusting The Middle Range Resonance Of The Master Equalizer [Midq]; Adjusting The High-Middle Range Resonance Of The Master Equalizer [Highmidq] - Yamaha P-250 Owner's Manual