The QSC HPR151i is a compact 15-inch active subwoofer designed to deliver powerful, precise bass for medium-sized sound systems. It combines a high-performance amplifier with a rugged construction to provide deep, clear low frequencies, while being durable enough for regular use in concerts or DJ setups. Key Features: Built-in 700-watt (Class H) amplifier for high sound output. Very low frequency response down to 43 Hz (at –10 dB) for deep, impactful bass. Maximum peak sound pressure level of 133 dB, delivering powerful low-end performance. Durable birch plywood enclosure with a 16-gauge steel grille for strength and protection.