Right up there with taking self pics with your iPad on the “Don’t, Just Don’t” list is trying to fill a room with laptop audio. No sir. If you’re gonna try to rock a party with your computer, you’re gonna need something like the Meridian Explorer ($299). This pocket-sized USB DAC (digital-to-analog converter) aims to improve the sound from your Mac, Windows or Linux-based system. Handmade at Meridian’s Cambridge factory, the Explorer features high-quality filter capacitors, a 6-layer PC board, and an all metal enclosure.