(Last Updated On: July 30, 2020)

Learn why audio seems out of sync when you’re watching and listening with a pair of Bluetooth headphones (and how to fix it).

Bluetooth wireless headphones
Photo by Obi Onyeador (From: Unsplash)

You’re watching a music video on YouTube using your favorite pair of Bluetooth headphones.

As you watched the drummer bang on the cymbals, however, you realized something’s amiss:

Why is the sound out of sync with the movements in the video?

You inspect it closer, slowing down the video speed a bit to confirm the sound delay.

And you were right.

The singer’s lip movements, guitar strumming, and all other sound effects in the music video are a bit off-sync. Minutes later, a quick Google search tells you that what you’ve experienced is caused by Bluetooth audio lag.

In this article, we’ll discuss what causes this and show you various steps on how to fix sound delay on Bluetooth headphones.

Why Do My Bluetooth Headphones Have a Delay?

To get a better grasp of what causes Bluetooth audio delay and how to fix it, you first need to know about audio latency. Next is to understand how sound is transmitted wirelessly via Bluetooth and the various audio codecs used to relay audio data.

Audio latency is defined as the time it takes for audio data to travel from its source (computer, smartphone, mp3 player) to your headphones or speakers. These are the ms it takes to process digital data and convert it to an audio signal that can be streamed through a wired or wireless connection to your headphones.

In a regular wired connection, the typical audio latency is 5-10 ms. In a wireless connection, Bluetooth latency can go anywhere from an ideal 34 ms (aptX LL) up to 100-300 ms for true wireless earbuds and headphones.

In a Bluetooth audio chain, you have a transmitter and a receiver. The transmitter sends the audio signal to the receiver. This audio signal uses a certain bandwidth to “travel” from source to destination. The bigger the audio signal’s file size (higher quality equates to larger audio files), the more bandwidth it needs to get to the receiver.

Think of bandwidth as the size of the road while the audio file size is the amount of traffic. If the traffic exceeds what the road size can accommodate, traffic jams will happen, reducing movement to a slow crawl (more time required to complete the transmission).

If there isn’t enough bandwidth to support a particularly large audio file transmission (e.g. you’re listening to a lossless audio file), then the transfer won’t go as fast and smooth, and this will reflect as audio stutter and lag.

Note that while wired connections are better in terms of audio latency, using Bluetooth headphones doesn’t necessarily mean you’ll hear noticeable sound delay all the time. As you’ll learn in a bit, there are several factors that come into play which determines if you’ll have near-imperceptible audio latency or experience some noticeable delay.

Factors that Affect the Quality of Bluetooth Audio

There are 4 important elements that will affect your listening experience when using Bluetooth headphones:

  1. Bluetooth Codec
  2. Interference
  3. Distance between source and receiver
  4. Bluetooth version

Bluetooth Codec

A Bluetooth codec is an algorithm that compresses, encodes, and decodes digital audio data. During the compression stage, it reduces the file size of the audio data (so it wouldn’t eat up too much bandwidth) and encodes it in a certain format for transmission. Then, it decodes that compressed data so it can be converted into an audio signal that we can hear.

There are several Bluetooth audio codecs available and each one has its own unique formula for compressing and transmitting audio data.

The most important thing to remember is that some codecs are better than others when it comes to streaming music over Bluetooth, and those are the ones that you ideally want to have your source and Bluetooth headphones to support to help ensure a smoother listening experience.

Interference

Interference refers to unwanted frequency signals that hijack and disrupt the clean signal between your source and Bluetooth headphones. Your wireless mouse, WiFi connection, television, and other similar types of appliances and gadgets that emit some form of radio frequency could negatively impact the flow of signal to your Bluetooth headphones.

Distance between source and receiver

There’s a maximum amount of distance you can get away from the audio source before you start losing connection and experience choppiness in what you’re listening to. Walls and other similar forms of physical blockage also worsen signal transmission.

Bluetooth version

Like Bluetooth audio codecs, not all versions of Bluetooth are created equal. There have been significant improvements with the technology incorporated in Bluetooth throughout the years. The latest standard, Bluetooth 5.0, can process audio data faster than previous versions which lead to shorter latency times and better sound quality.

How Do I Fix the Sound Delay on My Bluetooth Headphones?

Let’s be clear about one thing:

Audio delay will always be present in a wireless connection. But there are ways to minimize it so it won’t be too noticeable

As we’ve explained earlier, the whole process of encoding, transmitting, and decoding audio data wirelessly will always take up more time versus on a wired connection.

But while there’s no actual way (at least right now) to completely eliminate Bluetooth audio delay, there are several things you can do to make it less noticeable.

Picking the right audio codec

Let’s start with the codec. For all platforms (PC, Mac, Android, and iOS), using the ideal codec for Bluetooth streaming and having a pair of Bluetooth headphones that support it is crucial.

Try to look for Bluetooth headphones that support the following codecs: aptX, aptX HD, aptX LL, LDAC (Sony only), LC3, and Samsung Scalable Codec (Samsung only). These are superior to the old and universal codec, SBC, which was introduced in 2003.

Match the source and headphones Bluetooth audio profile

Next is matching the source and the headphones’ Bluetooth audio profile. If both your source and receiver are using the latest Bluetooth 5.0, the connection will be utilizing Bluetooth 5.0 standards.

If either the source or the receiver is Bluetooth 4.1 while the other is Bluetooth 5.0, the default connection will fallback to Bluetooth 4.1. Try to get the latest Bluetooth 5.0 support for both the source and receiving device to take advantage of its improved bandwidth and features.

In most cases, doing both of these above tips should reduce sound delay in Bluetooth headphones to an almost unnoticeable amount.

But if you already did both and still notice the audio out of sync, then perhaps a little bit of troubleshooting on your devices is required. The following are various steps you can follow to fix common Bluetooth issues on Windows, Mac, Android, and iOS.

How to Fix Bluetooth Audio Issues in Windows

If you’re using a Windows computer, there are several ways you can optimize your Bluetooth connection.

Option 1: Reconnect your Bluetooth Device

Sometimes the most effective solution is the most obvious one. Reset your Bluetooth headphones and speakers then try reconnecting them again to your computer after a few seconds. With luck, it would reset the laggy connection and improve audio sync.

Option 2: Download and Install the Latest Bluetooth Driver

Windows installs the appropriate driver to run your Bluetooth headphones the first time you try to connect it. It won’t, however, update to the latest drivers unless you manually do so. In some cases, audio lag in Bluetooth headphones may be caused by outdated software drivers. Here are the steps for updating your Bluetooth headphones’ drivers to the latest version:

  1. Right-click on the Start button (Windows logo), then select “Device Manager” from the list.
  2. Click the arrow pointing to the right beside “Bluetooth”.
  3. You’ll see a list of all Bluetooth devices that currently work with your computer.
  4. Look for the name of your Bluetooth headphones then right-click on it.
  5. Select “Update Driver” then follow the proceeding steps.
How to Update Your Bluetooth Headphone Device Drivers in Windows 10
How to Update Your Bluetooth Headphone Device Drivers in Windows 10

Option 3: Via Windows Audio Playback Troubleshooter

Windows 10 features a built-in troubleshooting feature for providing fixes to common problems you’ll encounter on your computer. To use this feature to try and fix a laggy Bluetooth connection, follow these steps:

  1. Right-click on the Speaker icon in the lower-right corner of your taskbar. Select “Troubleshoot Sound Problems”
  2. A pop-up window will appear with a selection of your audio devices. Choose your Bluetooth headphones then click “Next”.
  3. Follow the on-screen prompts for troubleshooting the device.

Option 4: Reboot the Windows Audio Service

The last option is to restart the Windows Audio Service which is a background task that runs all the time to manage all audio playback and output on your computer. To restart it, follow these steps:

  1. Hold down the Windows key (on your keyboard) then press R to launch the “Run” dialog box
  2. Type services.msc then hit Enter.
  3. Scroll down to the bottom of the window that will appear and look for “Windows Audio”.
  4. Right-click on it then select “Properties”.
  5. On the “General” tab, select “Automatic” for the Start-Up type.
  6. Click the “Recovery” tab.
  7. On the drop-down selection for First Failure and Second Failure, select “Restart the Service”. Click OK.
    How to Reset Windows Audio Properties
    How to Reset Windows Audio Properties
  8. Do the same steps for Windows Audio Endpoint Builder.
  9. Restart your PC then reconnect your Bluetooth headphones.

How to Fix Bluetooth Audio Issues in Mac

The following are tips for making sure the Bluetooth connection in your Apple computer is in tip-top condition.

Option 1: Delete Old Bluetooth Files

System errors caused by corrupted files is a possible reason why your Bluetooth connection acts up. Removing them all from your computer could improve your Bluetooth headphones’ wireless connection.

  1. Launch Finder. On the Menu bar, click on “Go” and select “Go to Folder”
  2. Type /Library/Preferences on the window that will pop up then click Go.
  3. A new window will appear. Look for the file, “com.apple.Bluetooth.plist” then right-click it to select the option, “Move to Trash”.
  4. Repeat step 1 but this time, type ~/Library/Preferences/ByHost for step 2. Hit Go.
  5. On the new Finder window, look for the file, com.apple.Bluetooth.xxxxxxxx then right-click it to select the option, “Move to Trash”. Note that the “xxxxxxxx” part stands for a combination of numbers and letters which varies from one computer to another.
  6. Restart your computer and try reconnecting your Bluetooth headphones again.

Option 2: Mac Bluetooth Module Reset

  1. On your keyboard, press and hold the Shift and Option keys at the same time.
  2. Your Menu Bar will appear, revealing the Bluetooth menu.
  3. Select “Debug”, then “Remove all devices”. This will disconnect all Bluetooth devices from your computer.
  4. Repeat all steps but this time select, “Debug” then “Reset Bluetooth Module”.
  5. Try reconnecting your Bluetooth headphones again along with your other wireless devices.

How to Fix Bluetooth Audio Delay in Android and iOS?

For both of these mobile operating systems, your best bet is to make sure you’re using the Bluetooth audio codec that works best for each OS (and having a pair of headphones that support that codec).

For iOS, you’ll have the best wireless listening experience if your headphones support the AAC codec as it’s Apple’s codec of choice. For Android, aptX LL and aptX HD are your best options.

Developer Mode Settings for Android Bluetooth Audio
Developer Mode Settings for Android Bluetooth Audio

Some codecs are manufacturer-specific, such as LDAC for Sony and Samsung’s Scalable Codec. If you’re using these smartphones, check your Android settings if it’s enabled and make sure to get a pair of Bluetooth headphones that support them.

And as mentioned above, using the Bluetooth 5.0 for both your source and receiver should improve audio latency significantly, so try to use devices that feature this latest standard. There are 3rd-party devices available in the market right now that attach to computers (Windows and Mac) and smartphones that will let you transmit audio using Bluetooth 5.0.

Conclusion

Will future advancements in BT technology completely eliminate sound delay? Only time will tell. But you don’t have to wait for that, really. Using the information and tips you learned here, you should experience significantly less sound delay when watching a video and listening using your Bluetooth headphones.

What do you think of the guide overall? Did it help solve some of your Bluetooth lag problems? Let us know in the comments section below.