Metal has recently become the go-to material for premium earphones, and like V-Moda’s $100 Vibe Duo and Maximo’s $70 iP-HS2, Super.fi 4vi’s earpieces are made entirely from metal—here, machined aluminum that’s been dual-finished with a matte body and a polished barrel. Just like V-Moda, Ultimate Ears has positioned its non-detachable cables on an ear-friendly 45-degree angle rather than sticking them straight out or down,…