With a 2–4 Band EQ, a maximum of four filters may be active simultaneously, with each of the five Peak bands (Low Shelf/Peak, Low Mid Peak, Mid Peak, High Mid Peak and High Shelf/Peak) counting as one filter. Each of the Band-pass and Notch filters (High Pass, Low Notch, Low Pass and High Notch) counts as
two filters.
When any combination of these filter types uses the four-filter maximum on the 2–4 Band EQ, the remaining bands become unavailable. This is indicated by the Band Enable buttons turning light gray. When filters become available again, the Band Enable button on inactive bands turns dark gray.