The P.Audio SW-181S is a high output passive subwoofer designed for use outdoor with full weather protection. Its enclosure is made with rotomolded polyethylene that is water proof and UV resistant. There are 10 M10 suspension points that provide kit flexible mounting options. The grille is made from CNC punched steel and is coated with a two-layer zinc-rich powder coating.

The woofer features a steel frame and a large-format voice coil. The cone material has been treated with a waterproof coating on its front and surfaces to protect against moisture intrusion and humidity. The woofer has a ferrite magnet with FEA design that provides high levels of magnetic flux. The grillw assembly is amde with three layers - a structural steel front with a dual-layer, zinc-ric powder coat; a layer of hydrophobic cloth that breaks down rainwater and forces it towards the bottom and a layer of reticulated foam that traps any moisture and allows it to evaporate.

The SW-181S is appropriate for fixed installations or for event production when weather resistance is required. It has an IP rating of IP44, allowing it to be used permanently in outdoor environments.