Image sourced from Reddit

Buzzing or humming noises in condenser microphones are mainly the result of ground loop problems. This issue is easily resolvable, but you need to be patient in the troubleshooting process so you can get the job done smoothly.

The buzzing and humming sound comes from electrical interference or grounding issues. These issues produce unwanted noise that leads to an irritating sound that disturbs the audio signal and creates an overall bad sound. It deteriorates the audio quality, and the recordings do not sound like professional recordings. The listeners have a bad experience.

So, if you want to sound professional in your audio recordings, broadcasts, and live performances, then sound these sound issues.

This blog post will provide a detailed guide on identifying and diagnosing the ground loop issue. The practical solutions provided will help you resolve these problems and improve the audio recording quality. So stay tuned until the very end!

Understanding Ground Loops 

The ground loop is an issue that arises when multiple connected grounding points result in different ground potentials. These different ground potentials create a loop for stray currents to flow, leading to an audible hum or noise in the audio signal.

The ground loop issue creates unwanted electrical currents, which interfere with the audio signal and affect the clarity and quality of the audio recordings.

These issues are crucial to examine because the background hum and buzz damage the overall sound quality and cause listeners to have a bad experience. Proper understanding helps in the appropriate diagnosis of the buzzing and humming noise issue.

This issue makes the audio sound dull and unprofessional, especially for professionals who are performing live or recording. So, addressing the issue at the start and removing all the root causes of the issue is essential to maintaining a clear and high-quality sound production.

How Ground Loops Cause Noise 

Mechanism of Noise Generation

The noise generation due to a ground loop issue is done for two reasons. One is electromagnetic interference and the second is single path interference.

Electromagnetic interference (EMI) from ground loops occurs when unwanted currents create magnetic fields that disrupt the audio signal. This interference creates a persistent hum or buzz in the audio output, which is picked up by sensitive microphone components.

The other one is single-path interference. In single-path interference, the interference from ground loops affects the audio signal path by introducing extraneous noise into the signal. This can distort or muddy the audio, reducing clarity and impacting the overall quality of the recording or playback.

Types of Noise

The main type of noise that is produced is 60Hz Hum (or 50Hz).it is due to the fact that the power grid is 60hz or 50 Hz. This low-frequency hum is a result of alternating current (AC) interference and appears as a steady, low-pitched background noise in recordings.

There can be different types of other additional sounds to the hum; ground loops can also cause hissing, static, or crackling sounds. These noises result from more erratic or broadband interference picked up by the audio equipment.

Why It is Essential to Deal with Ground Loop Issue 

Here are some points that pinpoint the issue, stating why it is required to solve the issue.

Reduced Signal Clarity

One of the prime reasons why one should deal with the ground loop issue is that it creates unwanted noise that distorts the audio signal clarity. The clarity of the audio signal is required in order to generate better audio of high quality in post-production. So, to ensure your sound is free from noise, you are advised to cure the ground loop issue as quickly as possible.

Altered Audio Balance

Another reason for dealing with the ground issues is that the interference can throw off the balance of your audio mix. For example, unwanted noise can distort the clarity if you’re mixing vocals and instruments, making it hard to distinguish between different audio elements.

Inconsistent Volume Levels

It is essential to deal with ground loop issues because the fluctuating noise levels due to ground loops can make your audio levels uneven, causing distortion. This inconsistency can lead to parts of your recording being too loud or too soft, so the audio will sound like it has no flow and would sound odd.

Loss of Audio Precision

The detail in the audio is diminished due to the ground loop noise. The clarity of the sound and details of the recording are lost when there is an issue with ground loops. This would seem like a real issue in conditions where you need high precision, like you want the mic to pick the delicate brush of a cymbal.

Looks Unprofessional

Noise problems can make your recordings sound unprofessional. Whether it’s a podcast, music track, or any other audio project, background hum, and buzz can make it seem like your setup isn't up to par.

Complicated Post-Production

The ground loop issue complicates post-production. Removing ground loop noise during editing becomes a hassle. It often requires additional time and tools to clean up the audio, which can be frustrating and time-consuming. Audio producers who are busy and don't have time would be more disturbed by this issue. 

Listener Distraction

With a persistent hum and buzz, the listener's overall experience is disturbed. They are distracted, pulling their attention away from the content. Instead of enjoying the audio, they might focus on the annoying background noise.

Symptoms of Ground Loop Issues

Here, we have some symptoms of ground loop issues.

Persistent Hum or Buzzing Noise

The ground loop issue is characterized by a low-frequency continuous hum or buzzing sound in the audio. The hum or buzzing sound mostly has a frequency of 60 Hz, but it depends on the power frequency. So, if you are experiencing a persistent hum or buzz sound, then it is a clear indication that you have a ground loop issue in your setup.

Intermittent or Fluctuating Noise

Another sign that you might have a ground loop issue is intermittent or fluctuating noise. This noise may change in intensity, appearing and disappearing spontaneously.

This usually comes when there's a quiet moment in your audio. This fluctuating noise indicates a ground loop issue that must be resolved promptly.

Inconsistent Volume Levels

The inconsistency in the volume levels that do not match the levels set on the source may indicate the presence of a ground loop issue. When you have set the audio setting to a desired volume, then if it is changing and is inconsistent, there might be chances that the issue is due to the grounding loop problem.    

Hissing or Static Noise

High-frequency noise superimposed on the original audio signal indicates the presence of the ground loop issue. When grounding is not done properly and the loop allows the passage of stray current, high-frequency noise can be produced, deteriorating the whole audio signal.

Electrical Interference

The electrical interference in the nearby electronic devices, like the flickering lights or other interference, also indicates a grounding problem.

You can use this indication as a sign and check out your electrical interference setup.

Noise Changes with Equipment Movement

Another sign is the noise changes with the changing of the equipment positioning. You might experience this issue as you change the position of your equipment and your noise levels change. This is a sign that there is an issue with the grounding or that your cable's shielding is improper. Either way, you will get a sign that the issue needs to be solved.    

Noise When No Signal is Present

Noise without any signal presence is also a sign that there is a grounding issue. In this case, there is no audio signal in the system, but even in its absence, a persistent hum or buzz noise is present. This indicates that the grounding is not done properly, which leads to this buzzing noise.

Increased Noise with Equipment Power

Another sign is the increased noise level when equipment is turned on. In this case, you would experience a fluctuating increase in the noise level when you turn on the power of equipment; this indicates that the stray current flows through the loop, and buzz noise is produced.

Hum with Multiple Devices Connected

Another sign is that the buzz sound will increase heaven when you add more audio devices to the same system. In the presence of multiple  devices, the buzz sound becomes more and more pronounced and thus indicates a grounding loop issue

Noise Affected by Cable Types

The buzz noise will also be affected by the cables. When you use different quality cables and experience a change in the noise level overall, this indicates that you have a grounding loop issue or your cables are not shielding properly, leading to their distortion of sound.

Diagnosing Ground Loop Issues 

Here, we have a step-by-step ground loop diagnosing guide.  

Preliminary Troubleshooting

Swap Out Microphones

The first step is swapping the microphones. When you experience a buzz or hum sound and you find out it is due to a ground loop issue, the first step is to change the microphone, causing an issue with an already known and tested microphone.

When you put the known and tested microphone in the place of this microphone causing an issue, make sure to use the same input and keep all the conditions the same. Now, see whether the issue persists or not. If it does, it means that the microphone was okay, and the problem lies in the grounding or there are other issues. If the problem had been in the microphone, the known microphone would have worked accurately. 

So, if the issue persists, then carry on to the next step.    

Test Different Cables

Now, in this step, use different cables. Take a working microphone and cables without any issue of hum or buzz, and remove the working microphone from that working cable. Now add the microphone that is causing issues with the cable setup working properly. Now, see whether your problem is still present or not. If the problem is still present, then the issue is with the cables, as we have already checked out that our mic is okay.

Test Different Inputs

Now, test the same cable and the microphone, which has been causing issues with the completely different inputs that are working properly.  See whether your microphone gives you this buzz or hum noise. If the buzz noise is not present, then the issue was with the problematic inputs before and not with the microphone and the cable.

If the issue is still present, then move on to the next step.

Check Microphone Switch

Check the microphone switch to see if the microphone is properly functioning. To do this, turn the switch on and off 3 to 4 times and leave it in the on position. This will let you know if there is an issue with the on-and-off switch that is causing the buzz noise. If the issue resolves, then it's okay; if not, move to the next step of adjusting the gain on the amplifier.

Adjust Gain Settings

If all those steps don't work, then the issue might be that your amplifier gain is high. In most inexpensive microphones, when the gain setting of your amplifier or the mixer is set on high, an increased level of buzzard noise comes. And that is unavoidable. So, to rescue this hum to a minimal level, it is advised to rescue your gain setting to a low level so the buzz is reduced

Here is a youtube video for you to solve the buzz or hum noise issue

Confirming Whether You Have a Ground Loop Issue

In order to confirm that the issue that you are facing is actually a ground loop issue, here are some steps to follow.

Confirm Scope of Noise

In order to confirm the scope of the noise you have to check all the microphone and ensure that all of them produce a hum or a buzz noise.This can be checked by following preliminary troubleshooting first step.

If you confirm that all of your microphone has this hum or buzz sound then move on to the next step.

Test with Different Cables

Now check the microphones with the different cables that are all working. Now check whether all the microphones on a different known working microphone cable are working or not.If the buzz noise is still present then move to the next step.

Confirm that it is Ground loop Issue

Now that you have come to the third step now it is confirmed that you have a ground loop issue and that needs to be resolved. 

Understand Dynamic Microphone Sensitivity

Image sourced form Reddit

The understanding of the dynamic microphone sensitivity is crucial.Some dynamic mics contain an internal hum bucking coil these bucking coils help in reducing the hum pick-up.This way  the hum is reduced to a greater extent but not eliminated. Example of such mics are Shure SM7B etc.

Whereas some mics models offer enhanced shielding around the voice coil to further minimize hum.Example of such models is Shure Beta 58.

But as we go further down the line into the cheap microphones list like the under 150$ ones like the shure beta 58 and the Fat Toad I-58 they lack the feature internal hum bucking coil that reduces the hum.

Overall all dynamic mics are susceptible to picking up some level of hum. To address the core issue, it's essential to focus on resolving the ground loop problem by ensuring proper grounding of your equipment and identifying the source of the noise interference.

Solutions for Ground Loop Issues

Use of Ground Loop Isolators

Image sourced from Reddit

Using ground loop isolators is an easy way to eliminate ground loop issues. These devices are designed to break the electrical connection between components while allowing the audio signal to pass through.

In-ground loop issues include the presence of a loop for stray currents to pass, but with the use of the ground loop isolators, the loop is interrupted, which leads to eliminating the unwanted noise caused by these loops.

Commonly used isolators include the ART DTI and the Behringer HD400, which are known for their effectiveness in reducing hum and buzz. When choosing an isolator, ensure it matches your audio setup’s requirements and has good reliability reviews.

Ensuring Proper Equipment Grounding

Image sourced from Reddit

Proper grounding of your audio equipment is crucial in preventing ground loop issues. The use of ground loop isolators is a good approach, but prevention is better than cure. 

Therefore, ensuring that all your devices are grounded correctly and using a single grounding point to avoid creating multiple ground paths is essential in reducing buzz and making your setup have optimal equipment grounding.

It is recommended that power outlets be checked and that quality power strips with built-in surge protection and grounding be used. Grounding issues often stem from faulty or inconsistent connections, so ensure that all cables and connectors are in good condition and securely connected.

Here is a youtube video link that would help you in the overall process of the buzz or hum noise issue fixation.   

What Others Are Saying.

Direct Quote	Source
“If there’s a buzzing noise it is usually a loose connection or a faulty cable. If you’ve tried replacing the cable, but are still experiencing an unusual noise, it could be a faulty microphone that has been damaged internally. Look up the manufacturer’s warranty and see if you can get a replacement or get it fixed.”	Click for Article
“All microphones have hissing and buzzing noises, but sometimes we might not even notice it until we turn on the microphone.”	Click here for Article
“In my experience, the most common cause is a loose set screw that’s supposed to be grounding the body of the mic, of a cable, etc. and/or XLR cables that stupidly leave the metal case floating when you hook two of them together….”	Click Here for Article
“The only thing worse than a buzzing mosquito is a buzzing microphone. The humming, hissing, and buzzing sound isn’t just annoying, it can ruin your recording.”	Click Here for Article
“There could be many reasons why your microphone is producing unwanted noise. It could be room background noise, an electrical problem or a problem with your cables. Try checking all your cables are firmly in place or swapping them with another cable to see if the problem still continues.”	Click here for Article
“Personally, I don’t think separate phantom power supplies make a lot of sense for computer recording these days. External sound cards of some quality will readily supply phantom power and you don’t have to meddle with batteries or ground-loop-susceptible additional power supplies.”	Click Here for Article
“Generally speaking there are three types of microphones, dynamic, condenser, and ribbon; all of which have something called a diaphragm. Diaphragms are like eardrums, they move back and forth when pushed by changes in air pressure (also known as sound).”	Click Here for Article
“if it’s a condenser mic you will have no sound with phantom off. if it buzzes when phantom is on you may have a bad mic cable.”	Click Here for Article
“The likely source of the problem is a hum field in your studio caused by the AC power lines.”	Click here for Article

Conclusion

Overall, the noise issue in the  microphone audio signal is typically caused by interference, and resolving it involves identifying the specific source of that interference and adjusting your setup accordingly. 

In many cases, this noise is a result of other equipment plugged into the same electrical circuit, which can include not only audio devices but also appliances like microwaves or even refrigerators.

To pinpoint the exact cause, you need to systematically eliminate potential sources of interference. Start by unplugging other equipment from the circuit and see if the noise persists. This process of elimination will help you isolate the problematic device or connection. 

If adjusting your setup doesn’t resolve the issue, a ground loop eliminator can be an effective solution to remove hum and hissing noise by breaking the unwanted electrical connection causing the interference.