Two Sound United companies located in Owings Mills, Definitive Technology and Polk Audio, producers of audio systems, on Friday unveiled lines of wireless music system products. Both companies’ products will play music in the home over Wi-Fi, streamed from a smartphone, tablet or PC. The systems use the Play-Fi app, compatible with Android and Apple iOS. Definitive Technology says its higher-end systems will deliver audiophile-grade music. Its products are priced from $399 for a compact wireless speaker to $1,299 for a wireless sound bar with a subwoofer. Polk’s products are less expensive, from $179 for a compact wireless speaker to $699 for its sound bar/subwoofer combination.