Julyfox Virtual Dolby 3d Surround Sound Processor USB and RCA Input 3.5mm Earphone and Pre-out Output Hifi Music Sound Effector Home Car Audio Processor Dolby surround sound, with through switch and adjustment of the depth of surround sound , the treble and bass adjustment 2 way signal input: the USB input and RCA input, automatic switching, USB is preferred America virtual Dolby surround sound technology, can carry on the 3D stereo enhancement processing and 3D virtual surround sound processing Common stereo CD, VCD signal and the mono signal could provide impressive 3D stereo surround sound after processed by our product Support ASIO software