Hey there- there could be a few different variables here so it would likely be best to get a #1095200902262034452. That said, here are a few things to try for troubleshooting reasons: - you said it makes the sound with nothing in the port, but what if there is an xlr or instrument cable in the port with a mic or instrument attached? sometimes outside electronic interference enters ports easier if there isn't a mic or instrument in it. - have you tried turning other devices in your room/space off?