How To Fix Unwanted Speaker Noise

How to Fix Unwanted Noise in Active Speakers

Humming, buzzing, hissing, crackling and interference from active speakers can be frustrating, but unwanted noise does not always mean your speakers are faulty.

In many cases, the noise is being introduced by another part of the setup. Common causes include unsuitable cables, ground loops, high input-gain settings, nearby electrical equipment, USB interference or incorrect connections between balanced and unbalanced equipment.

Before arranging a return or repair, it is worth testing each part of your setup carefully. In this guide, we explain the most common causes of unwanted speaker noise and show you how to identify and fix them.

What Is an Active Speaker?

An active speaker has a built-in amplifier and connects directly to a mains power supply.

This is different from a passive speaker, which requires a separate external amplifier.

Active speakers are commonly used for:

• DJ setups
• Music-production studios
• Home recording
• PA systems
• Live performances
• Keyboards and synthesizers
• Gaming and multimedia setups

Because an active speaker contains its own amplification, it can reveal noise coming from the audio source, cabling, power supply or connected equipment.

Is a Small Amount of Hiss Normal?

A very small amount of background hiss can be normal with active speakers, particularly when the amplifier is turned up and no music is playing.

Every amplifier produces a certain amount of electrical noise. In a quiet room, you may hear a faint hiss when placing your ear close to the speaker’s high-frequency driver.

This does not necessarily indicate a fault.

The important question is whether the noise can be heard from your normal listening position or while music is playing.

If the hiss is clearly audible from several feet away, changes when equipment is connected or becomes louder when you move a cable, further troubleshooting is recommended.

Identify the Type of Noise

Different types of unwanted noise can point towards different causes.

Humming

A low, steady hum is commonly associated with a ground loop, unsuitable audio cable or power-related issue.

Buzzing

A harsher buzzing sound may be caused by electrical interference, a poor connection, USB noise, damaged cabling or a grounding problem.

Hissing

Hissing is normally related to gain settings, the speaker’s amplifier noise floor, poor-quality source equipment or an unbalanced connection.

Crackling

Crackling may indicate a loose cable, damaged connector, dirty control, unsuitable signal level or an issue with the source device.

Whining or Digital Noise

High-pitched whining, electronic chatter or noise that changes as you move a computer mouse is often caused by computer, USB or graphics-card interference.

Radio or Mobile-Phone Interference

Occasional clicking, pulsing or fragments of radio audio may be caused by mobile phones, wireless routers or poorly shielded cables.

Start by Disconnecting Everything

The first step is to establish whether the noise is coming from the speaker itself or from something connected to it.

Turn the speaker off and disconnect every audio cable from the input.

Leave only the mains power cable connected, then turn the speaker back on at a low volume.

If the unwanted noise disappears, the speaker itself is unlikely to be the cause. The noise is probably entering through the source device, audio cable or another connected component.

If the noise remains with nothing connected, move the speaker to a different mains socket and repeat the test.

For a pair of speakers, test each speaker separately. This will help determine whether the issue affects one speaker or the complete setup.

Turn the Speaker Gain Down

One of the most common causes of audible hiss is excessive gain.

Many active speakers have an input level or gain control on the rear panel. Turning this control to maximum can amplify the background noise from the speaker, mixer, controller or audio interface.

A better approach is to establish a sensible gain structure throughout the setup.

Begin with the speaker gain at a moderate position rather than fully clockwise. Then increase the output level from your mixer, DJ controller or audio interface until you reach a suitable listening volume.

This normally produces a cleaner signal than running the source at a very low level and heavily amplifying it at the speaker.

Avoid allowing the source output or speaker input to clip. Clipping can cause harsh distortion and may damage the speaker over time.

Use Balanced Audio Cables

Whenever possible, connect professional audio equipment using balanced cables.

Balanced connections are designed to reject electrical noise and interference picked up along the cable.

Common balanced connections include:

• XLR to XLR
• Balanced TRS jack to XLR
• Balanced TRS jack to balanced TRS jack

Balanced cables are particularly important when using longer cable runs or when audio cables pass near power adapters, extension leads, computers or lighting equipment.

Unbalanced connections such as RCA or 3.5mm mini jack are more susceptible to noise.

An XLR-shaped connector does not automatically make a signal balanced. Both the source output, the cable wiring and the speaker input must support a balanced connection.

Check You Are Using the Correct Cables

Using the wrong type of cable can introduce noise, reduce volume or cause one side of the signal to disappear.

For example, a stereo 3.5mm output should not usually be connected directly to a single balanced speaker input using a basic 3.5mm-to-TRS cable.

A stereo output contains separate left and right channels, while a balanced mono input uses the same connector contacts for a different purpose.

Connecting them incorrectly can cause phase cancellation, low volume or distorted sound.

For two active speakers, the stereo signal should normally be split correctly into separate left and right outputs.

Common examples include:

• 3.5mm stereo mini jack to two mono jack plugs
• 3.5mm stereo mini jack to two RCA plugs
• Two balanced interface outputs to two XLR inputs
• Two DJ-controller master outputs to the left and right speakers

Always check the output type of your source and the input type of your speakers before purchasing cables.

Replace the Audio Cables

A damaged cable is one of the easiest faults to overlook.

Internally broken conductors, loose connectors and poor shielding can cause humming, crackling, signal loss and intermittent noise.

Try replacing each audio cable with a known working cable of the correct type.

Do not simply unplug and reconnect the same cable. A cable can appear normal from the outside while still having an internal fault.

If the noise only appears when the cable is touched, moved or bent, the cable or connector is likely to be damaged.

Swap the Left and Right Cables

If the noise only affects one speaker, swap the left and right audio cables at the source.

If the noise moves to the other speaker, the speaker is probably not the cause. The problem is likely to be the cable, source output or channel feeding that speaker.

If the noise remains on the same speaker after swapping the source connections, swap the cables themselves.

This simple test can quickly separate a speaker issue from a cable or source issue.

Connect Both Speakers to the Same Power Supply

A ground loop can occur when connected equipment is powered from different mains sockets or electrical circuits.

This often produces a steady low-frequency hum.

Try connecting your speakers, mixer, controller, computer and audio interface to the same suitable extension lead or power distribution unit.

This gives the connected equipment a common electrical reference and can reduce ground-loop noise.

Make sure the extension lead is correctly rated for the connected equipment and is not overloaded.

Never Remove the Mains Earth

Do not remove the earth pin, use an unsafe mains adapter or modify a power cable to eliminate humming.

The earth connection is an important safety feature. Removing it can create a serious risk of electric shock.

If the noise is caused by a ground loop, the correct solution is to address the audio connection, power arrangement or source device rather than disabling electrical safety protection.

Test a Different Mains Socket

Electrical noise can sometimes originate from the mains supply.

Move the speaker to another socket and test it with all audio cables disconnected.

Ideally, try a socket in another room or on a different circuit.

If the noise only occurs in one location, another device connected to the same circuit may be introducing interference.

Possible causes include:

• Cheap power adapters
• LED lighting
• Dimmer switches
• Refrigerators
• Air-conditioning systems
• Phone chargers
• Laptop power supplies
• Lighting controllers

Move Audio Cables Away from Power Cables

Audio cables should not be tightly bundled together with mains cables.

Power cables, extension leads and adapters can generate electromagnetic interference that is picked up by an audio cable.

Where possible, keep audio and power cables separated.

If an audio cable has to cross a power cable, crossing at approximately a right angle can reduce the amount of interference compared with running the cables alongside one another.

Disconnect Your Laptop Charger

Laptop power supplies are a common cause of noise in DJ and studio setups.

If your speakers are connected to a laptop through a DJ controller, mixer or audio interface, unplug the laptop charger and run the computer temporarily from its battery.

If the noise disappears, the charger or its connection to the mains is likely to be contributing to the problem.

Try powering the laptop and audio equipment from the same extension lead. You can also test a genuine replacement power supply that is suitable for the laptop.

Do not continue using a damaged or unsafe laptop charger.

Check for USB Interference

Computers can introduce electronic noise through USB connections.

This may sound like a high-pitched whine, static, pulsing or a changing noise when the computer is performing tasks.

Try the following tests:

• Connect the device to a different USB port
• Replace the USB cable
• Remove unnecessary USB devices
• Avoid unpowered USB hubs
• Move the audio device away from the computer
• Disconnect external monitors temporarily
• Test the setup with another computer

On a desktop computer, front and rear USB ports may behave differently because they can be connected to different internal controllers.

A short, properly shielded USB cable is normally preferable to a very long or poor-quality cable.

Test Without the Computer

If possible, connect a different audio source directly to the speakers.

For example, use a phone, standalone DJ system, keyboard or another suitable device with the correct cable.

If the speakers are quiet with the alternative source, the original computer, audio interface or USB connection is probably causing the unwanted noise.

If the same noise appears with several unrelated sources, continue testing the speakers, cables and mains connections.

Check Your Audio Interface or DJ Controller

The speakers can only reproduce the signal they receive.

If the output from a DJ controller, mixer or audio interface is noisy, the speakers will amplify that noise.

Check the device’s master level, channel gains and software settings.

Make sure:

• Input channels are not clipping
• The master output is not clipping
• Unused inputs are turned down
• Microphone gain is not unnecessarily high
• The correct output device is selected
• The latest suitable driver or firmware is installed

Also check whether the noise can be heard through headphones connected directly to the source device.

If the noise is present in the headphones, the issue is being introduced before the signal reaches the speakers.

Check Microphone and Instrument Inputs

Open microphone or instrument inputs can add considerable noise to a system.

Microphone preamps provide a large amount of gain. If a microphone channel is turned up without a microphone connected, it may produce noticeable hiss.

Turn down or mute any inputs that are not being used.

For microphones and instruments, use the correct input type and avoid turning the gain higher than necessary.

A microphone-level signal normally requires much more amplification than a line-level signal, so connecting equipment to the wrong input can create an incorrect and noisy gain structure.

Check the Input Sensitivity Setting

Some active speakers include input-sensitivity options such as:

• Line
• Mic
• Consumer level
• Professional level
• +4dBu
• -10dBV

Select the setting that matches the connected source.

A DJ controller, mixer or audio interface should normally connect to a line-level input rather than a microphone input.

Connecting a line-level source to a microphone input can overload the input and create distortion. Connecting a weak source to an unsuitable line input may require excessive gain, increasing hiss.

Turn Off Nearby Wireless Devices

Mobile phones, Wi-Fi routers and other wireless devices can sometimes interfere with audio equipment.

Move your phone away from the speakers, cables and audio interface.

Temporarily switch off nearby wireless devices to see whether the noise changes.

Older phones and poorly shielded audio cables are particularly likely to produce pulsing or clicking interference.

Move Power Adapters Away from Audio Equipment

Power adapters can generate electrical noise.

Avoid placing laptop chargers, USB power supplies and speaker power adapters directly on top of audio cables, interfaces or mixers.

Keep power supplies physically separated from low-level audio equipment wherever possible.

If the noise changes when an adapter is moved, the adapter or cable shielding may be contributing to the problem.

Check for Lighting Interference

DJ lighting equipment, LED strips and dimmer-controlled lights can introduce interference into an audio system.

Turn the lighting equipment off and listen for any change.

If the noise disappears, power the lighting from a separate suitable circuit where possible and keep lighting-control cables away from audio cables.

Cheap LED power supplies and dimmer packs can be particularly noisy.

For professional events, audio and lighting power should be planned carefully rather than connected randomly across overloaded extension leads.

Check Turntables Are Properly Grounded

Turntables can produce a strong hum if the ground connection is missing or incorrectly connected.

If your turntable has a separate ground wire, connect it to the ground terminal on the mixer or phono preamp.

Also check that the turntable is connected to a phono input unless it has a built-in preamp and is set to line output.

A turntable connected directly to a line input without a suitable phono preamp will normally sound extremely quiet and incorrect.

Some turntables use an internal grounding arrangement and do not require a separate ground wire, so check the manufacturer’s instructions for your model.

Check Your Speaker Volume Controls Match

For a pair of active speakers, set both speakers to the same input level.

If one speaker has considerably more gain than the other, its background noise may be more noticeable.

Matching the controls also makes it easier to judge whether a problem affects one side of the system.

Use the source device to control the general listening level once a suitable speaker-gain position has been established.

Avoid Turning Every Control to Maximum

Maximum settings do not necessarily produce the best sound.

Running the speaker input, mixer master, channel gain and software output at maximum can cause clipping and distortion.

Equally, running the source extremely quietly and compensating with maximum speaker gain can increase audible hiss.

A clean system uses sensible levels at every stage.

The signal should be strong enough to remain above the noise floor without exceeding the maximum level of any device in the chain.

What Is a Ground Loop?

A ground loop occurs when connected audio equipment has more than one path to electrical ground.

Small differences between those ground points can create a current that becomes audible as humming or buzzing.

Ground loops often appear when:

• A laptop is connected to mains power
• Speakers are connected to different wall sockets
• Unbalanced audio cables are used
• A television or display is connected to the computer
• Several pieces of equipment are connected through USB
• Audio equipment is connected across different electrical circuits

Using balanced audio connections and powering interconnected equipment from the same suitable mains distribution point can often reduce the problem.

Should You Use a Ground-Loop Isolator?

An audio ground-loop isolator can sometimes remove humming from an unbalanced connection.

These devices use transformers to break the direct electrical connection between components while allowing the audio signal to pass.

However, inexpensive isolators may reduce bass response, lower the signal level or affect sound quality.

They are normally better treated as a solution for a specific confirmed ground-loop problem rather than the first troubleshooting step.

Where possible, a properly designed balanced connection is usually the preferred solution.

Can a DI Box Help?

A suitable DI box can help when connecting unbalanced equipment to a balanced professional sound system.

It can convert the signal, provide a ground-lift function on the audio connection and allow the use of balanced XLR cables.

DI boxes are commonly used with:

• Laptops
• Keyboards
• DJ controllers with unbalanced outputs
• Instruments
• Consumer audio devices

The ground-lift switch on a DI box affects the audio connection. It is not the same as removing the safety earth from a mains plug.

Why Do Studio Monitors Sometimes Hiss?

Studio monitors are designed to reveal fine details in an audio signal.

This means they can also reveal noise that may be less obvious through consumer speakers.

Common causes of studio-monitor hiss include:

• Rear gain controls set too high
• An inexpensive audio interface
• Unbalanced computer connections
• High microphone-preamp gain
• Noise from a connected laptop or desktop computer
• Listening very close to the high-frequency driver

A faint amount of close-range hiss can be normal. Loud hiss that is clearly audible at the listening position should be investigated.

Why Do PA Speakers Sometimes Hum?

Active PA speakers are often connected to several pieces of equipment in electrically demanding environments.

Humming at a venue may be caused by:

• Long unbalanced cable runs
• Audio and lighting sharing unsuitable power
• Different mains circuits
• Poorly grounded source equipment
• Damaged extension leads
• Microphone inputs with excessive gain
• Incorrect mixer-output connections

Professional PA connections should normally use balanced XLR cables.

If the system is quiet at home but noisy at one particular venue, the venue’s power arrangement or another connected device may be involved.

Why Does the Noise Change with Computer Activity?

If the noise changes when you scroll a webpage, move the mouse, open software or play a computer game, it is likely to be computer-related electrical interference.

Desktop graphics cards, power supplies, USB controllers and motherboard components can all contribute to this type of noise.

Try using balanced outputs from a dedicated audio interface rather than connecting the speakers directly to the computer’s headphone socket.

Also test alternative USB ports, remove unnecessary USB equipment and connect the computer, interface and speakers to the same suitable power distribution unit.

Why Does Only One Speaker Make Noise?

If only one speaker is noisy, test the system in stages.

First, disconnect the audio cable from the affected speaker.

If the noise disappears, swap the left and right source outputs. If the noise moves, the problem is before the speaker.

Next, swap the audio cables. If the noise moves with the cable, replace the cable.

If the same speaker remains noisy with no audio cable connected and when tested from a different mains socket, the speaker may require inspection.

Why Do Both Speakers Make the Same Noise?

If both speakers produce identical noise, it is less likely that both speakers have developed the same fault at the same time.

The cause is more likely to be something shared by both speakers, such as:

• The source device
• The computer
• The audio interface
• The mixer
• The mains supply
• The cable type
• A shared power adapter

Disconnect the source completely and test each speaker individually to narrow down the cause.

A Step-by-Step Troubleshooting Checklist

Work through the following tests in order:

1. Turn the speaker volume down before changing any connections.
2. Disconnect all audio cables from the speakers.
3. Test each speaker individually with only mains power connected.
4. Try another mains socket.
5. Set the speaker gain to a moderate position.
6. Reconnect one source device only.
7. Replace the audio cables with known working cables.
8. Use balanced cables wherever supported.
9. Connect all related equipment to the same suitable power distribution unit.
10. Disconnect the laptop charger and test using battery power.
11. Try another USB cable and USB port.
12. Remove USB hubs, external displays and unnecessary devices.
13. Turn off nearby lighting, phone chargers and wireless equipment.
14. Test another audio source.
15. Swap the left and right outputs and cables.
16. Listen through headphones connected to the source device.

Change only one thing at a time. If several parts of the setup are changed together, it can be difficult to identify what actually fixed the problem.

When Could the Speaker Be Faulty?

The speaker may require inspection if:

• The noise remains with all audio cables disconnected
• The same speaker remains noisy in different mains sockets
• One speaker is significantly noisier than an identical matching speaker
• The speaker crackles when completely stationary
• The noise changes as the speaker warms up
• There is distortion at low listening levels
• The speaker repeatedly cuts out
• There is a burning smell or excessive heat

Stop using the speaker immediately if there is smoke, a burning smell, visible damage or any concern about electrical safety.

Do not open an active speaker, as it contains mains-powered electronic components and may retain dangerous electrical voltages even after being unplugged.

Information to Provide When Requesting Support

If troubleshooting does not solve the issue, provide as much information as possible when contacting the retailer or manufacturer.

Useful details include:

• The speaker model
• Whether one or both speakers are affected
• The type of noise
• Whether the noise remains with no audio cable connected
• The connected source equipment
• The exact cables being used
• The speaker gain position
• Whether the problem occurs in another mains socket
• Whether another audio source has been tested
• A clear video recording of the noise

A video should show the full setup, the connected cables and the position of the volume controls. A close recording of the speaker alone may not reveal where the noise is entering the system.

Frequently Asked Questions

Should active speakers be completely silent?

Not necessarily. A faint hiss may be audible when listening very close to the high-frequency driver. It should not normally be intrusive from the usual listening position.

Why do my speakers hum when I connect my laptop?

The laptop charger, USB connection or an unbalanced cable may be creating a ground loop. Disconnect the charger temporarily, use balanced cables and connect the equipment to the same suitable power supply.

Why is the speaker quiet until I connect an audio cable?

This usually indicates that the noise is entering through the source equipment, audio cable or electrical connection between devices rather than being generated by the speaker.

Will expensive cables remove speaker noise?

A properly made cable of the correct type can solve noise caused by damage, poor shielding or an unsuitable connection. Extremely expensive cables are not required, but the cable must be suitable for the equipment.

Are XLR cables always balanced?

Most professional XLR audio connections are balanced, but the full connection is only balanced if the source output, cable wiring and destination input are all designed for balanced operation.

Can I connect active speakers directly to a laptop?

Yes, but a laptop headphone output is normally unbalanced and may introduce noise. A suitable external audio interface with balanced outputs will usually provide a cleaner professional connection.

Why do my speakers make noise when no music is playing?

The noise may be amplifier hiss, excessive gain, noise from the source device, a ground loop or electrical interference. Disconnect the audio cables to determine whether the noise is coming from the speaker or the connected setup.

Can Bluetooth fix a ground loop?

A wireless Bluetooth connection can break the physical audio connection between devices, which may remove a ground loop. However, Bluetooth may introduce latency and reduced audio quality, making it unsuitable for DJ monitoring and professional performance.

Should I use RCA or XLR cables?

Use balanced XLR or TRS connections where both devices support them. RCA is suitable for shorter consumer-level connections but is more susceptible to interference.

Can I use a microphone cable for active speakers?

A properly wired balanced XLR microphone cable can normally carry a balanced line-level signal between a mixer and active speaker. Make sure it is a genuine audio signal cable and not a speaker cable intended for passive speakers.

Final Advice

Unwanted noise in active speakers is often caused by the complete setup rather than the speakers themselves.

Start by testing each speaker with no audio cables connected. Then reconnect the system one component at a time, using suitable balanced cables and sensible gain settings.

Pay particular attention to laptop chargers, USB connections, unbalanced outputs, power adapters and lighting equipment, as these are frequent sources of humming and interference.

By changing one part of the setup at a time, you can usually identify the source of the unwanted noise and correct it without replacing your speakers.

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