Full brown noise with grey EQ, comb and resonant filters, in a slow sixteen-second cycle
Preview plays right here. The generator adds a sleep timer, full controls, and WAV export.
Cave Ambience is the deep, echoing hush of a large underground chamber: a low rumble with a hollow, resonant color, swelling and fading so slowly it feels like the rock itself breathing. Water drips and wind are implied by the filtering rather than spelled out.
The color is full brown at 4 with grey EQ on. A comb filter with a 25 millisecond delay and 60 percent feedback adds resonances spaced about 40 Hz apart, and resonant filters at 100, 150 and 200 Hz with a Q of 12 add a low chamber tone. The envelope rises over 4 seconds, holds for 6 at 50 percent and releases over 5, a sixteen-second cycle, with a sine pulse at 0.05 Hz swelling every twenty seconds.
It suits sleep, meditation and anyone who wants the darkest textured preset. Seaside Cave in the nature category is the unfiltered, wetter cousin at 3.8, and Spaceship Hull is the same filter recipe tuned brighter and more metallic. Of the three it is the darkest and slowest, and the most likely to disappear into the background over a long night.