The Garden Oasis Sub 8 In-Ground Subwoofer uses high-output, high-excursion, water resistant drivers inside a HDPE enclosure (the same material used for underground water systems), offering excellent rigidity and water resistance. The Garden Oasis Sub 8 was designed to be discrete with only the “mushroom cap” hood visible. This hood evenly distributes the bass, keeps the driver protected from the elements, and provides constant fresh airflow for years of worry-free operation.