In many circumstances, the 160Hz high pass filter will be all you need to get clear speech through your loudspeakers. However, the three band parametric equalisation gives you more control.
If you unsure about microphone equalisation try these next steps. Click on button 2 on the graph, then on the "enable band" box, then click the fourth filter type along - a high shelf.
You can now use button 2 again, this time moving it up or down and along the graph. You will hear the clarity of speech being re-produced change as you vary this filter. You will find a point where it sounds clear and natural, but without being harsh.