TSi400: Equipped with three 5.25-inch diameter bi-laminate organic fiber cone woofers / Equipped with 1-inch silk/polymer composite Dynamic Balance dome tweeter * TSi400: Frequency response: 34-25KHz / Recommended Amplification: 20-200 watts/channel * PSW10: Single 10-inch subwoofer in black with built-in high-current amplifier for big bass * Polk PSW10: 10- inch Dynamic Balance® woofer delivers both the deep pounding bass demanded by action movies and the speed and finesse required to bring music to life.