Buzzing and humming in the audio system is usually caused by a ground loop. There could be exceptions, like a broken circuit or a damaged microphone capsule. But a ground loop explains most of the buzzing cases.

Having the ground is always the starting point when setting up an audio system. It is essential for safety reasons and for noise elimination whenever you plug in sound equipment. But ground loop means the opposite.

Basically, what happens is that two devices are fighting to decide which one is the ground. Specifically, two AC devices have their input and output connected. Such as a powered amp is being used as a mixer output, and these two devices are powered by different wall outlets.

Then the horrible high-pitched noise is most likely to follow up, regardless of whether you move the equipment. In this case, if you are trying to get rid of static with a noise reduction process in software, you are going to get a washout signal. So the post-production just does not help at all. If you can not fix the ground loop, the buzzing will just be there.

On top of all troubleshooting, you had better plug everything into the same power strip or wall outlet. One note here, though almost all the sockets in your house should be properly grounded, you can still check if the buzzing comes from the socket by investing in an outlet tester. Or simply plug all the gears into another socket.

If there are limited sockets or the buzzing still can be heard, we are going to show the party piece - a ground loop isolator. It will break the ground connection between the I/O of two devices that are powered by separate wall outlets. It works as a DI box in a more professional setup where balanced and unbalanced audio will need to be considered.

But what we are talking about isconsumer-level audio, which means the input and output are both unbalanced, so a simple ground loop isolator will do the job. It grounds out electricity and allows your audio signal to be crisp and clean. It is also easy to add the isolator to the whole setup, take the audio system of a computer and speaker as an example, just put it between those two AC-powered devices.

So far, the humming in most cases should have been solved. If not yet, other troubleshooting you may also want to try out and see if it is a product issue. Use better quality audio cables. They are expensive, but they work. Placing audio equipment far from high-current power supplies and cables.