The Radius 4 MK2 is an advanced audio mixer that features a 4/3 band isolator, Variable Q high pass filter per channel, headphone add mix function, two headphone jack points, and an auxiliary return knob. Its redesigned internal circuitry provides excellent sound fidelity. Offering versatile sound formatting, it features switchable isolation for sound shaping, a VariableQ filter for low-frequency roll-off and options for headphone input.