Audioengine designs and manufactures our own tweeters, woofers, and other critical components. In other words, these are not “box built” speakers with off-the-shelf parts but custom-designed to our specifications. What we do not fabricate directly in our factory we have made to our designs (parts such as transformers, magnets, and wiring harnesses, for example). The cabinets, drivers, bass port designs, amplifiers, and crossovers are all painstakingly tuned together for each Audioengine model. This, in turn, makes for a much more efficient system that requires much less power than passive speakers and a separate integrated amplifier or similar A/V components.