They are powered by a Class AB amplifier contained in the left speaker rated at 45 Watts RMS and 70 Watts peak power. Each speaker features a 5" Kevlar mid-range driver /w advanced voice coils and a 20 mm silk dome tweeters with neodymium magnets. The cabinet is made of 1" thick MDF coated with your choice of glossy white or satin black finish. Rounding out the componentry of this speaker include a high-end torroidal coil and crossover.
The A5's include several input options for hooking up audio sources. There are two 1/8" stereo inputs (one on top, the other in back) for hooking up to your mp3 player, computer, or any other stereo source. Unique features include a USB charger on top for your mp3 player and second AC input for powering other devices including an Airport Express iTunes streamer.
Audioengine A5 powered speakers are much higher quality than typically found in stereo computer speakers or iPod docking stations, and because of this are more expensive coming in at $350. However, since you don't require an amplifier, these speakers can provide a great audiophile experience on a budget.
Consider a cheaper alternative in the M-AUDIO StudioPro 3 ($100) or their little brother, the Audioengine A2 ($199).