Question:

What causes a speaker to buzz when connected to a TV via AUX cable, but not when an HDMI cable is plugged into the speaker?

I have a speaker that has both AUX and HDMI ports, and a TV that does not support HDMI ARC. I use an AUX cable to connect the speaker to the TV, but the speaker produces a buzzing noise. However, the buzzing stops when I insert an HDMI cable into the speaker, even though the other end of the cable is not connected to anything. What is the reason for this phenomenon?

Answer:

If you have ever experienced a buzzing noise from your speaker when you connect it to your TV via an AUX cable, you might be wondering what causes this annoying sound and how to fix it. The buzzing noise is usually caused by a ground loop, which is an electrical interference that occurs when two devices have different ground potentials. A ground loop can create a low-frequency hum or buzz that is audible through the speaker.

A ground loop can happen when you connect your speaker to your TV via an AUX cable, because the speaker and the TV are both plugged into the same power outlet, but they have different paths to the ground. The difference in the ground potentials creates a small current that flows through the AUX cable and the speaker, resulting in the buzzing noise.

However, when you plug an HDMI cable into the speaker, even though the other end of the cable is not connected to anything, the buzzing noise stops. This is because the HDMI cable acts as a shield that blocks the interference from the ground loop. The HDMI cable has a metal casing that covers the wires inside, and this casing is connected to the ground of the speaker. The casing creates a barrier that prevents the current from flowing through the AUX cable and the speaker, thus eliminating the buzzing noise.

There are a few ways to solve the ground loop problem and get rid of the buzzing noise from your speaker. One way is to use a ground loop isolator, which is a device that breaks the ground loop and filters out the interference. You can connect the ground loop isolator between the AUX cable and the speaker, and it will stop the current from flowing through the speaker. Another way is to use a power conditioner, which is a device that regulates the voltage and cleans the power supply. You can plug both the speaker and the TV into the power conditioner, and it will balance the ground potentials and reduce the interference. A third way is to use a different type of cable, such as an optical cable or a coaxial cable, that does not carry the ground signal and is less prone to interference.

By understanding the cause of the buzzing noise from your speaker and applying one of these solutions, you can enjoy a clear and crisp sound from your speaker without any annoying interference.

— : [What is a ground loop?](https://www.howtogeek.com/299986/what-is-a-ground-loop-and-why-does-it-make-my-stereo-hum/) : [How to fix a ground loop in your audio system](https://www.cnet.com/how-to/how-to-fix-a-ground-loop-in-your-audio-system/) : [Why does plugging in an HDMI cable stop the buzzing from my speakers?](https://electronics.stackexchange.com/questions/220581/why-does-plugging-in-an-hdmi-cable-stop-the-buzzing-from-my-speakers) : [What is a ground loop isolator and how does it work?](https://www.lifewire.com/what-is-a-ground-loop-isolator-3134700) : [What is a power conditioner and why do you need one?](https://www.crutchfield.com/S-7LgQb8wY2gO/learn/learningcenter/home/power_conditioner.html) : [What are the differences between optical, coaxial, and HDMI cables?](https://www.digitaltrends.com/home-theater/optical-digital-coaxial-hdmi-cables/)