地底机械发现音

Deep subterranean discovery pad, 600 ms. A low 110 Hz struck metal tone swelling in slowly, joined by a thin high 1.8 kHz shimmer and a faint granular rock texture, fading out over 300 ms. Feels like descending into a new layer of a cold machine world. Dry, no reverb hall, no orchestral strings, no tribal drums. Louder and more present. Sustain the full stated duration.