Pioneer S MM251 computer speakers : Pioneer Electronics continues to expand its line of USB powered computer speakers with the introduction of the Pioneer S MM251. The Pioneer computer speakers offer a built-in audio DAC and a cool bass-reflex enclosure designed to enhance lower bass frequencies. The Pioneer S MM251 computer speakers are designed to connect quickly to virtually any laptop computer, delivering significantly increased audio output and better sound quality. The Pioneer S MM251 computer speakers are extremely compact and easy to transport, making it ideal for travel. The Pioneer computer speakers S MM251 are available in black as well as a silver version designed to complement the color of the Apple MacBook computers.