Let's get this out of the way: at 38mm (1.5 inches) thick, these Mythos XTR-50 speakers are not the "world's thinnest," no matter what manufacturer Definitive Technology might have you believe -- JVC dropped 31mm satellites onto our secret wishlists just last fall. But unless you live in Japan, the Mythos XTR-50 may be the thinnest speakers you can actually buy. Made completely from aircraft grade aluminum, the enclosure houses six domed drivers and a tweeter, themselves shaped from aluminum, and connected with copper-covered aluminum wire. Why all the aluminum, you ask? The obvious reason is that -- in moderation -- it's lighter and stronger than alternative materials, which contributes to these satellites' luscious curves, but it also means that the entire assembly acts as a giant heatsink. Logical design -- who would have believed it. Too bad the units cost $700 each, and you'll need at least two -- if not five -- to get the full effect.