I am using either a Sennheiser headset that plugs in using the pink and green plugs to the soundcard or a Raptor HD40 headset which connects via a USB 2.0 port. In either case I get a low frequency hum when I record to Audacity and I get this on a Lenovo X300 laptop running Windows 7 and Audacity 2.0.2, another Alienware 17 laptop running Windows 8.1 and a desk PC running Windows 7 both with the same version of Audacity. The two laptops are in the garage and the desk PC s in the house. The mains power to the garage comes from the house.
I have attached a small sample file of a recording of the hum and if there is anyway to get rid of it I would be grateful to hear how to do it/what’s causing it.
My Corsair headset is a USB connected device and as I said in my post, I get exactly the same outcome when using the Sennheiser headset which connects via the microphone/headphone sockets (the pink and green connectors) so I don’t think it’s relevant, sorry.
Can you run one of the laptops on batteries and try it again? Still on batteries try it out in the street or meadow.
I have a Giant Hummy Monster that lived in the attic. He makes recording in one of the bedrooms impossible because of excessive hum pickup—even on batteries. All equipment works famously outside of that room. It may also have to do with the high tension wires that go over the house (attached).
Traditionally it’s difficult to filter that sound in post production because it involves a number of frequencies. Hum isn’t one thing.
It’s possible you have wiring errors in your house. I’ve had several in mine. You can buy a wall power tester. This is what the US one looks like. It can test for reversed wires and “Hot” where “Neutral” should be.