Full brown noise at 4 with no EQ, no pulse, and a two-second fade, pure rumble
Preview plays right here. The generator adds a sleep timer, full controls, and WAV export.
Deep Brown is the sound of a waterfall heard from inside a cave, or a very large aircraft taxiing far away: almost entirely low end, with a soft, rolling rumble and hardly any hiss. It is the darkest single-color preset and the closest to a physical, felt sound.
The color is set to the full brown value of 4, which rolls off at roughly 6 dB per octave and is generated as a random walk, each sample being the last plus a small random step. Grey EQ is off, so the natural bass weight is left intact. There is no pulse and the fade-in is two seconds.
It is popular for sleep, for masking low-frequency noise and for people who find any hiss uncomfortable. Heavy Blanket is the same color with grey EQ and a longer fade, and Soft Air is the next step brighter at 3.4. It also serves as the bottom layer in Layered Depths, which blends a blue hiss over the top.