You hit record, deliver your best take, play it back, and there it is. That annoying buzz or hum running underneath everything. If you are wondering why you hear a buzz or hum in your recordings, you are not alone. This is one of the most common issues podcasters, musicians, voice actors, and content creators face.
I have spent years recording audio in home studios, treating rooms, and troubleshooting noise issues. Our team has dealt with every type of buzz imaginable, from faint electrical hum to loud, recording-ruining interference. In this guide, I will walk you through exactly what causes these sounds and how to eliminate them for good.
Buzz and hum in recordings is usually caused by ground loops, electromagnetic interference, faulty cables, poor shielding, or dirty power from your electrical system. The noise typically manifests as a 50Hz or 60Hz electrical tone that enters your signal chain through connected equipment and power sources.
That quick answer covers the basics. But actually diagnosing and fixing the problem requires digging into your specific setup. Let me break down every common cause, a step-by-step troubleshooting process, device-specific fixes, and post-production rescue methods so you can get clean recordings.
Table of Contents
What Causes Buzz and Hum in Recordings?
Understanding what causes buzz and hum in recordings starts with knowing how electrical noise enters your audio signal. There are several primary culprits, and most recording issues trace back to one or more of them.
Ground Loops: The Number One Culprit
A ground loop happens when two or more pieces of equipment in your audio chain are connected to different electrical grounds. When those grounds have slightly different voltages, electrical current flows between them through your audio cables. That current creates a low-frequency hum, usually at the same frequency as your mains electricity.
I once spent three days chasing a persistent hum in a podcasting setup. The problem turned out to be a laptop charger plugged into a different outlet than the audio interface. The moment I plugged both devices into the same power strip, the hum vanished.
Ground loops are incredibly common in home studios because we tend to spread equipment across multiple outlets. As one Reddit user in r/WeAreTheMusicMakers put it: “Sounds like a potential ground loop issue. Tends to happen when you’ve got your audio devices hooked up to the same power outlet” or, more accurately, when they are on different circuits entirely.
Cable and Connection Issues
Faulty cables cause more buzzing problems than almost anything else. A loose connection inside a cable, a damaged shield, or a bent connector can all let interference into your signal. The cable does not need to look broken on the outside to be passing noise into your recordings.
Unbalanced cables are particularly vulnerable. Standard RCA and quarter-inch TS (tip-sleeve) cables carry audio on a single wire with a basic shield. Any electromagnetic interference the cable passes near gets picked up and added to your audio. Over long cable runs, this becomes a significant source of buzz.
Balanced cables, like XLR and TRS (tip-ring-sleeve), use a clever trick to reject noise. They carry the audio signal on two wires with reversed polarity. When interference hits both wires equally, the receiving equipment flips one signal back and the noise cancels itself out. This is called common-mode rejection, and it is the reason professional studios run balanced cables everywhere.
A community member on r/podcasting gave this advice: “Try changing the cable. Most likely it’s a faulty cable, but electricity can impart interference on the signal.” This matches what I have seen time and again. Cable swaps solve roughly half of all buzzing complaints.
Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI)
Your recording space is full of electromagnetic fields. Power cables, fluorescent lights, computer monitors, routers, phones, and nearby transformers all emit electromagnetic energy. When your audio cables or microphone pass close to these sources, they act like antennas and pick up the interference.
EMI typically produces a buzzing sound rather than a pure hum. You might hear it as a harsh, raspy noise, sometimes with an audible data or radio component. Cell phones are notorious for this. If you have ever heard the “dit-dit-dit” buzz from a phone near speakers, that is RFI getting into the audio chain.
Fluorescent lights and dimmer switches are another major source. Dimmer switches in particular chop the AC waveform, creating broadband electrical noise that spreads through your electrical system and into your gear.
Faulty or Damaged Equipment
Sometimes the problem is not the cables or the environment. A damaged microphone capsule, a failing preamp in your audio interface, or a worn-out input jack can all generate noise. Internal damage to a microphone, especially condenser mics with delicate electronics, often manifests as buzzing or crackling.
As the microphone manufacturer TONOR notes: “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.”
Equipment age matters too. Older gear with degraded capacitors or loose internal solder joints can develop noise issues that get worse over time. If a piece of equipment has started buzzing suddenly after years of clean performance, internal failure is a likely suspect.
Phantom Power Issues
Phantom power (48V) is required to run condenser microphones. When something goes wrong with phantom power delivery, buzzing is often the first symptom. A StackExchange user described this exact scenario: “I have just connected a studio microphone to the phantom power which is connected to the sound card which is also connected…” and experienced noise issues.
Common phantom power problems include using a low-quality or failing phantom power supply, delivering phantom power through an unbalanced cable, or having phantom power engaged on a channel where it is not needed. Some audio interfaces also produce noise on their phantom power circuit, especially budget models.
If your condenser microphone buzzes the moment phantom power is engaged, try a different power supply or audio interface. The microphone itself may be fine, but the power delivery could be introducing noise.
Dirty Power and Electrical Environment
Dirty power refers to electrical current that carries noise, fluctuations, or interference from the building’s electrical system. Older buildings, circuits shared with heavy appliances, and areas with unstable power grids all contribute to dirty power.
Multiple forum users across Reddit mention “dirty power” as a common culprit. If your recordings buzz no matter what cables or microphones you use, and the buzz changes when you move to a different room or building, dirty power is likely the cause.
Refrigerators, air conditioners, and other motor-driven appliances on the same circuit introduce noise. Even your computer’s power supply can inject hash back into the electrical line if it is not well-filtered.
50Hz vs 60Hz Hum: What the Frequency Tells You
The frequency of the hum in your recording tells you something important. In countries using 50Hz mains power (Europe, Australia, most of Asia, Africa), electrical hum appears at 50Hz and its harmonics (100Hz, 150Hz, 200Hz). In countries using 60Hz mains power (United States, Canada, parts of South America and Japan), the hum appears at 60Hz and harmonics (120Hz, 180Hz, 240Hz).
This matters because it confirms whether your buzz is power-related. If you open your recording in a spectral analyzer or EQ plugin and see a sharp spike at exactly 50Hz or 60Hz, you are dealing with electrical interference from your power system. This is almost always a ground loop or shielding issue.
A Reddit user in r/musicproduction shared their frustration: “I’ve been going crazy all day trying to understand what is causing this situation.” The answer turned out to be a 50Hz spike from a ground loop, clearly visible when they analyzed the frequency content. Knowing the frequency narrows your troubleshooting significantly.
Buzz that does not sit at exactly 50Hz or 60Hz is more likely EMI, RFI, or equipment-related noise rather than a ground loop. This distinction helps you pick the right fix faster.
How to Fix Buzz in Your Recordings
Fixing buzz and hum requires a systematic approach. I recommend starting with the simplest, most common fixes and working your way toward more complex solutions. Here is the troubleshooting process our team uses.
Step 1: Swap Your Cables
Start here because cables are the most common cause and the easiest to test. Grab a known-good cable and replace every cable in your signal chain one at a time. Start with the microphone cable, then the cable from your audio interface to your monitors or speakers.
Listen after each swap. If the buzz disappears when you replace a specific cable, you found the problem. Even if the old cable looks fine externally, internal damage to the shielding or connections can cause noise. I keep a spare known-good XLR cable on my desk specifically for this purpose.
When trying this fix, wiggle the connectors gently while monitoring. If the buzz changes or cuts in and out, you have a loose connection at that point. Clean the contacts with electrical contact cleaner if they look corroded.
Step 2: Switch to Balanced Cables
If you are using unbalanced cables (TS, RCA) for any part of your signal chain, switch to balanced cables (XLR, TRS). This is especially important for cable runs longer than about 15 feet. Unbalanced cables become increasingly susceptible to interference as length increases.
Most professional audio interfaces and microphones support balanced connections natively. If your microphone has an XLR output, use it with an XLR cable into your audio interface. If you are connecting an interface to studio monitors, use TRS cables rather than RCA.
The difference can be dramatic. A buzzing unbalanced connection often goes completely silent when replaced with a properly wired balanced cable. The common-mode rejection built into balanced connections eliminates most induced noise automatically.
Step 3: Isolate Ground Loops
If cables are not the issue, test for ground loops. Plug all of your audio equipment into the same power strip or power conditioner. This ensures they share the same ground reference and eliminates voltage differences between grounds.
If plugging everything into one outlet fixes the hum, you had a ground loop caused by different circuits. If the hum persists, you may need a ground loop isolator. These small devices break the ground connection in the audio path while maintaining signal flow, stopping ground loop current.
For audio interfaces connected to computers via USB or Thunderbolt, the computer itself can create a ground loop through the data cable. Try a USB ground loop isolator, or lift the ground on the audio interface if it has a ground lift switch. Never lift the ground on the AC power side of your equipment, as this creates a safety hazard.
Step 4: Separate Audio and Power Cables
Run your audio cables and power cables along separate paths. When power and audio cables run parallel and close together, the power cable’s electromagnetic field induces hum into the audio cable. This is basic physics, and it causes more buzz problems than people realize.
If cables must cross, cross them at a 90-degree angle. This minimizes the amount of interference transferred. Keep audio cables away from power strips, wall warts (power adapters), and especially the thick power bricks on laptop chargers.
I once fixed a persistent buzz in a home studio simply by moving a microphone cable four inches away from a power strip. The cable had been running directly alongside it under the desk. Four inches of separation eliminated the noise entirely.
Step 5: Use Shielded Cables and Proper Cable Management
Not all cables are created equal. High-quality shielded cables reject interference far better than cheap, poorly shielded alternatives. Look for cables with dense braided shielding rather than thin foil shielding. Braided shields provide better coverage and longer-lasting protection against EMI and RFI.
Coil excess cable neatly rather than bunching it into a ball. Tight bundles of cable can act as antennas, picking up more interference. Use Velcro ties to keep runs organized and separated from power lines.
Avoid running cables across the floor where people step on them, and never pinch cables under furniture or heavy objects. Physical damage to the shielding inside the cable creates weak points where interference enters.
Step 6: Eliminate Nearby Interference Sources
Look around your recording space for devices that generate electromagnetic fields. Fluorescent lights, dimmer switches, computer monitors, routers, televisions, and power transformers are all common culprits. Turn off each one individually while monitoring your recording to see if the buzz changes.
Dimmer switches are especially problematic. If you have a dimmer on any light in your recording space, try turning it fully on or fully off. If the buzz only appears when the dimmer is partially on, the dimmer is your problem. Replace it with a standard switch or move your recording space.
Keep mobile phones away from microphones and audio cables. Even when not in use, phones periodically communicate with cell towers and can induce audible buzzing in nearby audio equipment. Putting a phone in airplane mode during recording eliminates this source.
Step 7: Check Phantom Power Configuration
If you use a condenser microphone, verify that phantom power is being delivered cleanly. Try a different audio interface or phantom power supply to see if the buzz disappears. Some budget interfaces deliver noisy phantom power that introduces buzz into the signal.
Only enable phantom power on channels that need it. Having phantom power engaged on channels connected to dynamic microphones or line-level devices can cause issues. Also make sure phantom power is off before plugging or unplugging microphones to avoid pops and potential damage.
Device-Specific Troubleshooting: Windows 11
On Windows 11, audio buzzing often relates to driver issues or sample rate mismatches. Open Settings, go to System, then Sound, and click your input device. Make sure the sample rate matches what your recording software expects (typically 44100Hz or 48000Hz).
Update your audio interface drivers directly from the manufacturer’s website. Windows generic drivers work, but they sometimes introduce latency and noise. If you are using a USB microphone, try a different USB port, preferably a USB 2.0 port on the back of the computer rather than a front panel or hub port.
Disable audio enhancements in Windows. Go to the Sound control panel, find your recording device, click Properties, and uncheck any enhancement options. Windows audio processing can sometimes introduce artifacts that sound like buzzing or crackling.
Device-Specific Troubleshooting: Mac
On Mac, sample rate mismatches between the audio interface and recording software are a frequent cause of buzzing. Open Audio MIDI Setup from your Utilities folder and verify that the format and sample rate match your DAW settings exactly.
If you are using a USB audio interface and a MacBook with a power adapter, try running the MacBook on battery power. If the buzz stops on battery, your charger is creating a ground loop through the USB connection. A USB ground loop isolator will fix this permanently.
Check for Core Audio conflicts. If multiple audio drivers are installed, they can conflict and produce noise. Remove unused audio drivers from your system and restart.
Device-Specific Troubleshooting: iPhone
If you hear buzzing when recording on an iPhone, the cause is often the charger. Recording while charging your iPhone creates a ground loop through the charging cable. Try recording on battery power to confirm. If the buzz stops, use a ground loop isolator designed for mobile devices.
Lightning and USB-C audio adapters can also pick up interference from the phone’s internal electronics. Keep the adapter and cable away from the phone’s antenna areas. Using a longer cable to position the microphone farther from the phone itself can reduce induced noise.
Close background apps before recording. Apps that use cellular or Wi-Fi radios can cause interference that gets picked up by connected microphones.
Software-Specific Troubleshooting: Audacity
In Audacity, buzz can sometimes come from buffer size settings that are too low. Go to Edit, Preferences, and then Devices. Increase the buffer size to 256 or 512 samples. Small buffer sizes cause audio dropouts and glitches that can sound like buzzing.
Make sure the audio host in Audacity matches your system. On Windows, try WASAPI or ASIO (if available) instead of MME for cleaner audio. On Mac, CoreAudio is the only option but ensure the sample rate matches your interface.
Software-Specific Troubleshooting: FL Studio
FL Studio users on Reddit frequently report 50Hz hum when arming tracks for recording. The most common cause is ASIO driver settings. Open your ASIO settings and increase the buffer length. If the buffer is too small, you get crackling and buzzing from underruns.
Also check that FL Studio is using the correct audio interface driver. Using the Primary Sound Driver instead of your interface’s dedicated ASIO driver will produce noise and latency. Switch to the manufacturer’s ASIO driver for clean audio.
Post-Production Fixes: Removing Buzz After Recording
Sometimes you cannot fix the buzz at the source. Maybe you already recorded a session and noticed the hum afterward. Or the source of the interference is out of your control. In those cases, post-production tools can rescue your audio.
I want to be clear about something: fixing buzz in post-production is always a compromise. It is better to prevent the noise before recording whenever possible. But these tools have gotten remarkably good, and they can save recordings that would otherwise be unusable.
EQ and Equalization
The simplest post-production fix is a narrow EQ cut at the frequency of the hum. If you have a 50Hz hum, place an EQ plugin on the track, create a narrow notch filter at 50Hz, and cut it deeply. Then add additional notches at the harmonics: 100Hz, 150Hz, 200Hz.
For 60Hz hum, do the same at 60Hz, 120Hz, 180Hz, and 240Hz. The harmonic frequencies are where the hum does most of its damage, so cutting them is just as important as cutting the fundamental.
Most DAWs include a parametric EQ that can do this. In Audacity, use the Graphic EQ or Filter Curve tool. In Adobe Audition, use the Parametric Equalizer. In FL Studio, use the Fruity Parametric EQ 2. Set the Q value high (narrow bandwidth) so you only remove the hum frequencies without affecting the surrounding audio.
High-Pass Filter
A high-pass filter removes all frequencies below a chosen cutoff point. Since most voice recordings do not contain useful information below 80Hz, a high-pass filter set to 80Hz removes the fundamental hum frequency without affecting voice quality.
This works well for moderate hum but does not address the harmonics. Use it in combination with EQ notching for best results. Many audio interfaces and preamps have a built-in high-pass filter switch, usually labeled “low cut” or “HPF.” Engaging this before recording prevents hum from ever reaching your DAW.
Noise Gate
A noise gate mutes or reduces audio below a set threshold. When you are not speaking, the gate closes and the hum disappears. When you speak, the gate opens and the hum returns but is masked by your voice.
This does not remove the hum, but it makes it far less noticeable during silent passages. A Reddit user on r/WeAreTheMusicMakers recommended: “A good noise gate will fix a lot of buzzing problems” as an effective band-aid solution while you track down the root cause.
Set the threshold just above the hum level but below your quietest speech. Adjust the attack and release times to sound natural. Too fast and the gate clicks. Too slow and it sounds sluggish.
Dedicated Noise Reduction Tools
Modern noise reduction plugins can analyze a section of pure hum and then remove that exact noise profile from the entire recording. Audacity’s Noise Reduction tool does this for free. Capture a noise profile from a quiet section, then apply noise reduction to the full track.
Adobe Audition’s Noise Reduction process works similarly and offers more control. Third-party plugins like iZotope RX, Waves NS1, and CrumplePop AudioDenoise use advanced algorithms to separate noise from desired audio with impressive results.
Be careful with aggressive noise reduction settings. Too much processing introduces artifacts that sound like underwater bubbling or robotic warbling. Start with gentle settings and increase gradually until the hum is reduced without degrading voice quality.
How to Prevent Buzz and Hum Before It Starts
Prevention is always better than fixing noise after the fact. Here are the practices our team follows to keep recordings clean from the start.
Use balanced cables everywhere possible. XLR for microphones, TRS for line-level connections. This single habit eliminates the majority of buzzing issues before they start. Buy quality cables from reputable brands with good shielding and sturdy connectors.
Plug all audio equipment into the same power strip or conditioner. This prevents ground loops by ensuring a single ground reference. A power conditioner also filters dirty power, reducing electrical noise from the building’s system.
Keep audio cables and power cables physically separated. Route them along different paths under or around your desk. Where they must cross, do so at right angles. This simple practice costs nothing and prevents induced hum.
Turn off fluorescent lights, dimmer switches, and other known interference sources before recording. Put your phone in airplane mode. Close the door to block outside electrical noise.
Invest in a quality audio interface with balanced outputs and clean phantom power. Budget interfaces save money upfront but often introduce noise that costs hours of troubleshooting later.
Common Causes of Buzz and How to Fix Each One
Here is a quick reference guide mapping each common cause to its likely fix:
Ground loop (50/60Hz hum): Plug everything into the same outlet or use a ground loop isolator.
Faulty cable: Swap with a known-good cable and listen for changes.
Unbalanced cable over long run: Switch to balanced XLR or TRS cable.
Phantom power issue: Try a different power supply or audio interface.
Dimmer switch or fluorescent light: Turn off or replace with standard lighting.
Phone or wireless device nearby: Move away or enable airplane mode.
Dirty power from building: Use a power conditioner or try a different room.
USB ground loop from laptop charger: Run on battery or use a USB isolator.
Buffer size too small in DAW: Increase buffer to 256 or 512 samples.
Sample rate mismatch: Match interface, system, and DAW sample rates.
FAQs
Why is there buzzing in my recording?
Buzzing in recordings is most commonly caused by ground loops, faulty or unbalanced cables, electromagnetic interference from nearby electrical devices, or dirty power from your building’s electrical system. Start troubleshooting by swapping cables, then check for ground loops by plugging all equipment into the same outlet.
What causes the mysterious hum?
The mysterious hum in your recordings is typically an electrical ground loop or electromagnetic interference picked up by your audio cables. The hum usually sits at 50Hz (in countries with 50Hz mains power) or 60Hz (in countries with 60Hz mains power) and enters your signal chain through unbalanced cables, shared power circuits, or proximity to electrical devices.
How to get rid of microphone hum?
To get rid of microphone hum, first swap your microphone cable with a known-good one. If that does not help, switch to balanced XLR cables, plug all equipment into the same power strip to eliminate ground loops, and move audio cables away from power cables. If the hum persists, try a ground loop isolator on the affected connection.
How to eliminate humming noise?
Eliminate humming noise by addressing the source: use balanced cables, plug all gear into one outlet, separate audio and power cable paths, and remove nearby interference sources like dimmer switches and phones. For noise already in a recording, use a narrow EQ notch at the hum frequency (50Hz or 60Hz) plus its harmonics, or apply dedicated noise reduction software.
How to get rid of buzz in audio recording?
To get rid of buzz in an audio recording, apply a high-pass filter at 80Hz to remove low-frequency hum, use EQ to notch out 50Hz or 60Hz plus harmonics, apply a noise gate to silence hum during quiet passages, or use dedicated noise reduction tools like Audacity Noise Reduction or iZotope RX to analyze and remove the noise profile from the track.
How to get rid of phono hum?
Phono hum is caused by the same electrical interference as other audio hum. Fix it by ensuring your turntable ground wire is connected to your amplifier’s ground terminal, using shielded cables between the turntable and preamp, moving power cables away from phono cables, and plugging all audio equipment into the same grounded outlet. A phono-specific ground loop isolator can also help.
What causes unwanted hum in audio?
Unwanted hum in audio is caused by ground loops between interconnected equipment, unbalanced cables picking up electromagnetic interference, proximity to power transformers and fluorescent lights, dirty electrical power, faulty cables or connectors, and issues with phantom power delivery to condenser microphones.
Conclusion: Clean Recordings Are Within Reach
If you have been asking yourself why you hear a buzz or hum in your recordings, the answer almost always comes down to one of a handful of causes: ground loops, faulty cables, electrical interference, dirty power, or equipment issues. The good news is that every one of these problems has a proven fix.
Start with the simplest solutions first. Swap your cables, plug everything into the same outlet, and separate your audio and power cable runs. Work through the troubleshooting steps systematically rather than guessing. And when prevention is not possible, post-production tools like EQ notching and noise reduction can rescue compromised recordings.
Clean audio is achievable for anyone willing to diagnose the problem methodically. Take it one step at a time, and you will have professional-quality recordings without that unwanted buzz.