PRV Audio's Alto Series 10W650A-4 is an impressive driver, without a high-end price. This 4 ohm 10" is a great woofer for any high output system such as pro audio or even high SPL automotive systems. With 97 dB efficiency and 325 watt of continuous power handling, this driver is capable of extremely high output. In addition, the 10W650A-4 has a wide frequency response of 75 to 5,500 Hz, making it suitable for use in high-end guitar and bass amps.