Sure you can complement your PMP with a full-size cans, but the Ultimate Ears 18 Pro Custom Monitors ($1350) packs great listening experience in a tiny package. Inside each ear are custom six-speaker system, which delivers detail and clarity to the bass, mids, and highs, while optimally reproducing the total pro audio frequency range from powerful visceral low end to defined high notes. The 8 Pro Custom Monitors also include four-way crossovers, triple-sound channels, -26 dB of isolation and passive noise cancellation, cable built for durability and reduced distortion, a customized aluminum carrying case, and more.