No matter how sophisticated the engineering behind wireless headphones, their wire-free performance is inherently bound by the Bluetooth technologies they, and the smartphone (or other audio source) they are used with, support.
Sennheiser recognises this, and with its latest flagship wireless noise-cancelling over-ears, the HDB 630, has sought to improve things. How? By bundling in a clever little accessory that blesses your phone (or other audio source) with the same high-quality Bluetooth codec the headphones themselves support.
