Yamaha"s compact NS-AW150 bookshelf speakers provide an affordable way to enjoy your music or television programming on a deck or under a porch. You can bring them in during the cold months and set them up indoors, too: their high build quality and good sound lend them equally well to two-channel indoor listening. The speakers, which are sold as a pair, each use a 6.5-inch high-compliance, polypropylene, mica-filled woofer and 0.5-inch PEI dome tweeter. The drivers are optimized for high rigidity but low mass, giving them reasonably high sensitivity (80 dB with 2.83V at 1 meter), another way of saying modest amplifiers won"t have much trouble driving them. Their acoustic-suspension cabinets are sealed to prevent undue resonance or tubby, tuneless bass, which often results from low-cost ported designs.