C2G/Cables to Go 40428 3.5mm Stereo Audio Isolation Transformer Stop speaker hum due to the effects of ground loops; an easy connection via standard 3.5mm cables Helps to reduce noise in an audio system caused by an electrical ground loop 3.5mm Stereo Audio input and output Frequency response from 20 Hz to 20 kHz Input: 3.5mm Female, Output: 3.5mm Female Every installation technician has faced it or soon will - the dreaded humming from the speakers, a telltale sign of a ground loop Ground loops are caused by voltage potential differences at the ground point on your equipment Frequency Response: 20 Hz ~ 20 kHz Frequency Response: 20 Hz ~ 20 kHz