MainEQ is a modern equalizer designed to offer precise sound shaping with a comprehensive set of features. It includes ten parametric filters such as resonant low-shelf, high-shelf, and multiple peaking filters, along with high-pass and low-pass options. The graphical interface provides intuitive control, allowing users to manage dynamic filtering with upward and downward actions, and a unique tilt filter for tonal balancing.

This equalizer supports advanced functionalities like Mid/Side filtering, enabling each filter to be balanced between mid and side signals for detailed stereo control. Filters can be grouped as 'Polys' for synchronized movement or alternate adjustments using control keys. The Global Action control scales all filter gains simultaneously, offering a parallel EQ effect without phase distortion, enhancing overall mix clarity and flexibility.

MainEQ also features powerful inter-band and inter-track dynamic control, allowing one frequency band or track to influence another, such as sidechaining bass guitar EQ to a bass drum. Its log-scale spectrum analyzer helps monitor input, output, and other tracks, while spectral matching tools enable frequency carving and flattening across tracks for better mix space. Additional conveniences include preset sharing through plain text, auto-gain matching, invert functions for complementary settings, and quick templates with undo/redo support.