Image via Koostik
If you're looking for an iPhone speaker dock that is energy efficient, you'll be hard pressed to find something that uses less than the Koostik. It uses zero. Made entirely of solid wood, it amplifies the sound coming from the iPhone's built-in speaker, giving you louder music without needing to plug anything in.
Koostik states that there's some types of music that works better than others.
KOOSTIK is not intended as a replacement to electronic amplifiers in all situations. If you're into Heavy Metal at high volume or heavy sub base sounds, KOOSTIK may not be your cup of tea. But if you like intimate vocals and instrumentals in relaxed settings, KOOSTIK will blow you away (gently of course).
It certainly uses fewer materials and a simpler manufacturing process than the Phonofone we saw back in 2007.
While it comes in a few different types of wood -- walnut, cherry and birdseye maple -- there's no mention as to whether or not these are FSC woods sustainably sourced.