2-Pack Ground Loop Isolator, Hum/Buzz/Noise Eliminator for Home Theatre, Speaker or Subwoofer Connected to Cable, Isolation Transformer for Cable TV Applications & Antenna(5-1218Mhz)HUM NOISE ELIMINATORA must have for Home Theatre Connected to Cable to perfectly get rid of ground loop hum. The isolation transformer can also be used to eliminate a 60hz ground loop hum created when the television was connected to an audio system. It is also recommend if your speakers or subwoofers are buzzing on cable tv. As an added benefit, the ground loop isolator show surge lightning protection up to 6kV. IMPROVE TV ANTENNA SIGNALGround loop