American Music Rentals Production Service is a great option for sound system rentals in the Seattle area. They have a nice selection of packages that include microphones, speakers, amps, mixers; everything needed for most events, including weddings, parties, conferences, and concerts. They also have technicians (sound guys) for hire that can help setup and run the equipment. Delivery is also available. Prices may seem high but they are reasonable and competitive with the other options in town (not many worth mentioning).