科幻护盾撞击循环

Seamless looping sci-fi shield impact ambience, one second that loops perfectly. A dense turbulent low-mid rumble around 120 to 400 Hz with irregular metallic pings scattering through it, like debris hammering an energy barrier. Heavier and more distorted than a UI sound. No reverb tail, no musical pitch, no melody, no fade in or out at the loop point.