TheTechLounge posted a review on the Audioengine W1 Wireless Audio Adapter

Audioengine's stellar A5 bookshelf speakers knocked me flat with perfect sound. The fact that this company would trust invisible air tubes over good ol' copper to not screw up their performance is a compelling sign that their new Audioengine W1 is dyed-in-the-wool wireless solution, but I'm hella skeptical. While I certainly don't believe that Monster's onto something with their oxygen-free copper and gold lies, I'm not positive that I won't be able to tell the difference between wires and nothingness.

Audioengine W1 Wireless Audio Adapter Review