ThirtyOne MK2 combines a 31-band spectrum analyzer with a graphic equalizer, both designed around the standard one third octave bands. This plugin emulates the behavior and time response of classic analog spectrum analyzers commonly used in live sound mastering chains. Its analog-inspired design delivers a familiar sound shaping experience, offering a reliable tool for frequency monitoring and adjustment within any audio production setup.

The equalizer section is crafted to capture the warmth and character of vintage analog units, enhancing the mastering workflow with a distinctive sonic signature. A standout feature is the Auto EQ, which automatically adjusts gain across EQ bands by analyzing the spectrum analyzer output. This dynamic tuning achieves harmonic balance effortlessly, allowing users to fine-tune the effect using customizable compensation curves. These curves can be saved and loaded, providing consistent results across multiple projects.

ThirtyOne MK2 offers flexible control including bypass and solo modes for each EQ band, multiple analyzer integration times, and options to view mid or side components of the audio spectrum. The plugin supports major formats such as Audio Units, VST2.4, VST3, and AAX on both macOS and Windows platforms, with a scalable, hardware-accelerated interface. Its efficient CPU usage and comprehensive preset management make it a powerful addition to any mastering or mixing environment.