|Graphical Equalizer is located under Spectrum window, and consists of a set of bars with sliders, each of them controlling relative volume of corresponding frequency range.
Similar to Equalizers in audio systems, TS-AudioToMIDI Graphic Equalizer controls amplitude of audio signal at each standard note frequency. Recognition algorithm works according to the following order: transforming from waveform to spectrum, multiplying by corresponding Equalizer values, analyzing spectral peaks and detecting notes. Thus Equalizer allows filtering out undesired peaks.
Unlike Filter tool that utterly throws out notes indicated, Equalizer allows controlling note rejection/acceptance smoothly depending on amplitude.
This is what Equalizer will most typically look like. The "hump" corresponds to frequency range of the melody.
Spectrum Analyzer and Keyboard