It’s amazing sometimes what one simple design tweak can do for a product. Case in point: Bowers & Wilkins’ elegant new C5 earphones.

As anyone with oddly-shaped auditory canals knows, most in-ear monitors rely on a dubious mix of proper tip/sleeve selection and getting the right seal. This can be harder than it seems, especially given that most earphones only come with three or four sleeve options. Even then, many are still prone to shift around or even pop out if you decide to do anything active with them.

The C5s all but eliminate this annoyance with a fancy little thing called…a loop. Y...