Not many things can be as annoying as a loud or not so loud but steady buzzing noise on a flat frequency, coming out of your speakers. More than a few things can cause this, and most of them are fixable in one way or another. If your speakers are causing you a headache, check the list below to identify your buzzing source and the possible solutions.
Too much power
This may sound weird but, if you are hearing a buzz and you are not playing anything, check your master volume level. If it is turned all the way up, and the buzzing stops after you turn down a volume a bit, that means your speakers are getting more power than they can handle. Play with the volume to figure out the point where the buzzing starts and stay below it if you want to keep your speakers functioning.
If you are hearing a constant 60 Hz buzzing from your speakers, you are probably suffering from the issue caused by unbalanced cables. You will hear this buzzing sound even if you don’t play any sound through your speakers and it will get worse if you place some electrical device near them or the cables.
What causes this to happen?
There are two wires inside your unbalanced sound cables. One is used to carry the signal from the amplifier, and one is for the ground. The cable acts as an antenna and picks up a lot of electromagnetic noise along the way. The ground is supposed to shield your signal from the noise but sometimes it’s not adequate for the job due to the bad quality or high level of noise and interferences. So, at the speaker’s end, you get both signal and noise. And this noise causes your buzzing.
If this is the case, you need to change the cables and get ones labeled “balanced”. They have three wires inside of the cable. Two of them are for the signal and a third one is for the ground. Two signal wires are transferring the signal in reverse polarity to each other. When the signal gets to the speaker, it reverses its polarity so that the signal in both wires has the same. However, since the noise picked up by both wires has reversed polarity, it cancels itself and you get a noise-free signal.
Alternatively, you can use a device called Di-Box to make your unbalanced cables behave like the balanced ones.
As a general rule, act preventively, and try not to run power and signal cables next to each other or crossing each other whenever possible. In many cases, all will be fine but in some, you will get a buzz from the speakers. Modern cables are isolated pretty well but it is better to be safe than sorry.
Ground loop problems
A ground loop is the most common issue causing buzzing and humming from your speakers. If you hear a 120 Hz hum from your speakers it is probably caused by a ground loop. A ground loop is being created when there are some devices plugged into the different AC outlets on the same line, then connected by an electrical connection. This loop acts as an antenna and picks up all kinds of electromagnetic interference. Anything that breaks this loop will stop the humming. All you have to do is figure out what works best for you.
You can solve this issue in many ways, depending on the situation.
Plug all the interconnected devices into the same extension cord.
In most cases, your ground loop will be caused by the cable TV antenna cable. If that is the case, all you need is a cable TV isolation transformer you can easily find in the store or online and it will cut the loop.
If you are unable to do No 1, and it is not No 2, use the AC “cheater plug” that separates the ground pin from the socket contacts and connects all of the devices, one by one, using a cheater plug. When the buzzing stops, you found the source of the problem. Then you can plug that device back using some ground line isolator device. That will prevent it from creating a ground loop in the future.
If it’s not an issue of unbalanced wires and it is not a ground loop, the source of your troubles could be in the speaker itself.
Speakers are generally made out of 3 major components + supporting electronics. Those major components are a central cap that acts as a dust cover, a diaphragm, and a sealant ring. The latter two are sensitive and damaging them can cause the air to create vibrations even when there is no signal. The diaphragm is a speaker component that vibrates and pushes the air, thus creating sound. It is usually made of some light material such as paper, nylon, or thin plastic. If it gets damaged, it can create a buzz. The same goes for the rubber ring holding a diaphragm in place. If one or more of those critical components get damaged, the only way to fix the problem is by replacing them in service.
The three most common issues can make your speakers buzz.
Too much power – if the buzzing stops when you turn down the master volume, that means your speakers are getting more power than they can handle. Keep your volume below the buzzing level and you should be fine.
Unbalanced wires, commonly identified by the 60 Hz low hum.
If this is the case, replace your speaker cables with the ones labeled “balanced” or connect them through DI-Box.
Ground loop identified by the 120 Hz buzz
If the cause of your problems is a ground loop, all you need to do is break it. You can do this in several ways. You can rearrange your devices so they get all plugged into 1 extension cord, or you can use some kind of isolator/filter such as a ground line isolator.
If your speaker’s diaphragm or ring gets damaged or torn, the only way to fix the problem is to take them to service and replace the damaged part(s) or the speaker.