The KH 420 is a three-way tri-amplified monitor with thermally protected Class AB amplifiers (330 W and two times 140 W). Just like the drivers, its Mathematically Modeled Dispersion™ (MMD™) waveguide is engineered for optimum precision. Sound distributed in a horizontally precise manner ensures flexibility in the listening position; the narrower vertical dispersion reduces the negative effects of nearby reflections, for example from a desk or mixing console. The dispersion of the KH 420 is deliberately designed to be narrower, to guarantee reference sound at longer working distances.