Underwater 2: Multi-Effect Filter and Lo-Fi Plugin by Thenatan Audio

The core of Underwater 2 is a modeled filter with smooth resonance. The Slopes menu sets how steeply it cuts, from 12 to 96 dB per octave across eight filter stages. A Low-Cut switch removes everything below 80 Hz, which helps keep the low end clear when the filter is pushed.

The Redux knob adds lo-fi degradation through bit and sample rate reduction, and the Drive knob applies a distortion algorithm with up to 36 dB of gain. Together, these controls cover the main moves for a filtered, underwater-style effect: cutoff, slope, degrade and saturation.

The interface can be resized by dragging the bottom-right corner, and Ctrl+click returns it to 100 percent. A tooltip strip explains whichever control the mouse is over, and the bypass is toggled by hovering over the panel and clicking.

Underwater 2 supports automation, so the filter, Redux and Drive controls can be moved over time in your DAW. The panel animation responds to the controls and to the input signal, so the on-screen feedback tracks what the effect is doing.