The New Wave of (Electricity-Free) Speakers
With sleek styling, acoustic "passive amps" are taking wireless music to the extreme.
Mini Koo by Koostik
Sound: Combined with the upward-facing speaker, the resonance of the wood gives music a subtle lift.
Style: Colorado craftsman Jim Simon tested 50 prototypes before settling on this rustic design, which comes in rich walnut or warm cherry wood. $70; koostik.com