Hifonics BRZ15D4 Brutus Dual Subwoofer, 4-Ohm 600-Watt 15-Inch Brutus subwoofers have earned a reputation in the industry for producing some of the most efficient and loudest subwoofers in their class. The "BRZ" subwoofer series makes no exception featuring three models that are designed to deliver accurate bass reproduction through a wide range of frequencies with impressive power handling capabilities. Hifonics innovative dual spider spacing technology is used in this series to ensure robust sound year after year. This unique design separates the two spiders to maximize excursion outward and inward while maintaining optimal control. The result is an astonishing increase in SPL output and strength. The rubber surround provides long excursion while the heat-dispersing ported nickel-plated back plate and ultra-rigid stamped steel basket ensure durability and reliability. Polypropylene cone and nickel-plated push and insert speaker terminals keep the amps energy focused within the speaker's core. Dual 4-Ohm configurations offer flexibility in 12” and 15” round and 12” square sizes ideal for sealed or ported enclosures. Powerful bass reproduction is rated at 1200 W Maxx and 600 W RMS. Square vs. Round The unique square-shaped subwoofer allows approximately 20% more cone surface area for moving air and generating higher SPL than the same sized round woofer. The square shape is ideal when space becomes a challenge in the confines of a car something Hifonics refers to as "More Bass in Less Space." Square Brutus subwoofers utilize Hifonics unique rubber surround design, which addresses the non-linear cone behavior of a square coned low-frequency bass driver. The special ribs formed into the rubber surround at the corners prevent the surround from bending or folding while the cone travels up and down, adding improved sound quality.