“Physical Impossibility? Mass Fidelity Packs Huge Stereo Into a Little Box” – Wall Street Journal. The Core is a compact speaker with ‘better than stereo’ sound. Wireless. Multi-room. Portable. Truly liberating. This beautiful little box sounds like two widely separated full size HiFi speakers with smooth highs, crystal clear midrange and bone shaking bass. Bring a universe of wireless sound into every part of your home.