Sennheiser has introduced a new all-back version of its Ambeo Smart Headset that will be sold exclusively in Apple Stores for $300. Unveiled last month at CES and designed expressly for iOS devices, the company’s new Ambeo headset connects via the Lightning port and features microphones on the outside of each earpice to provide 3D sound when recording audio or video, effectively creating what the company calls an “immersive life-like 3D…