The Klipsch KD-400 Powered Bookshelf Speakers are compact two-way monitors with a two-channel amplifier input on the rear of one speaker. The other speaker is passive & feeds off the amp of its partner speaker. Thus while these speakers function within active speaker systems they are powered rather than fully active. Connect through Bluetooth analogue & digital optical inputs as well as a subwoofer output for quick & easy setup. Your music will be delivered by Klipschs unique Dhorm tweeters which combine the advantages of both horn & dome designs for the best of high-frequency sound quality & power efficiency. These Dhorm tweeters also feature a unique cooling system for enhanced power handling & dynamic range. Proudly designed & engineered at Klipschs worldwide headquarters in Indianapolis these speakers demonstrate the brands commitment to excellence & energy efficiency. Order the KD-400 from AV.com & youll also receive a FREE Fisual Connection Cable Pack specifically tailored to streamline powered speaker setup.