Set the pad to -10 or -20 dB to avoid distortion when miking loud sources such as drums or guitar cabinets. Activate the high-pass filter at 40, 80, or 160 Hz for attenuation of low-frequency problems including rumble and proximity effect. The OC18's housing is constructed of zinc-aluminum alloy for strength and durability. The OC18 Studio Set includes a vibration-reducing shockmount, a traditional mic clip, a windscreen for mitigating noise from breaths and blasts of air, and a protective carry case. Being 48 VDC phantom powered, the OC18 does not require batteries or an external power supply.