What is Bluetooth latency and how to minimize it

Source: Pocketnow video

CONTENT
CLOSE

We've all been there: you're happy watching a video on your phone using a pair of Bluetooth headphones. Suddenly you realize something is wrong. You notice there's a slight lag between the movement of the speaker's lips and when you actually hear the words through your headphones — there's a kind of lag. The delay you just experienced at this exact moment is called the Bluetooth audio delay.

Although Bluetooth latency, which causes lag and lag, is nothing new – it's been around since the technology was first developed – it has left many people pretty annoyed. In online games, in particular, Bluetooth audio lag can be extremely jarring. In this article, let's explain the root causes of Bluetooth lag, the factors that can affect it, how you can minimize Bluetooth audio lag, and why it may never (completely) go away.

What is the reason for Bluetooth audio lag?

To understand what causes audio lag in Bluetooth headphones, you need to know about latency. Latency, in computing terms, is the time taken for data to move from one point in a network to another (Going through cloudy). In our context, latency is the time it takes for audio data to travel from its source (your smartphone, TV, games console, or PC) to its destination (your headphones, headphones, or speakers).

Despite the many developments in this area, the minimum latency achieved in modern Bluetooth headphones and earphones is still around 34 ms (aptX Low Latency). Although this delay seems very small, it is much higher than the delay that occurs in wired headphones (usually between 5 and 10 ms). For reference, an average Bluetooth earphone, the AirPods, for example, experiences a latency of around 150ms.

This again begs the question: why do Bluetooth headphones have higher latency (and therefore audio lag) than wired headphones? To understand why wireless headphones have much higher latency than wired headphones, you need to understand the chain of events that occur when data (audio in this case) is transferred from a device to Bluetooth headphones.

Since the raw data cannot be transferred wirelessly, the audio data is converted into a format compatible with Bluetooth transmission. It is often compressed, so data transfer takes less time (the smaller the data size, the faster the data is transferred). The data is then transmitted to the Bluetooth headphones, where it must first be converted into an analog audio signal, and only then can it be played. This all takes time, and while we're talking milliseconds here, those extra steps can delay the process and thus increase the lag you experience when using Bluetooth headphones.

Factors That Affect Bluetooth Lag

• Codec: As shown above, an audio file is converted to a format suitable for transmission before being transferred wirelessly. An audio codec is an algorithm that compresses, encodes and decodes digital audio data (Going through Headphones). There are a number of codecs available, each with their own pros and cons. Ideally, you want the codec of your Bluetooth headset to match the codec of your source device. Otherwise, the setup will simply revert to the older Bluetooth audio codec – SBC or Low Complexity Subband Coding, which is prone to audio delays.

• Interference: With so many wireless devices around, unwanted frequency signals can interrupt the connection between your device and Bluetooth headphones. Many devices, including wireless mice, smartwatches, smart home devices, and others, operate on the same frequency as Bluetooth. These devices emit their own signals, which can hinder the flow of data from your device to the wireless headphones.

• Distance between source device and Bluetooth receiver: Wireless connections have their own drawbacks, and one of them is that they only work up to a certain distance. Thanks to recent developments in this field, Bluetooth devices can now work up to a distance of 800 feet. However, walls and other physical blockages can affect data flow and thus cause Bluetooth lag.

• Bluetooth version: Just like the codec, the Bluetooth version also plays an important role. It is important that the Bluetooth version of your two devices (the source and the receiver) match. Otherwise, you will only be able to use the features of the lowest Bluetooth version. For example, if your smartphone has Bluetooth 5.2, but your wireless headphones only support Bluetooth 5.0, you will only be able to use the features of Bluetooth 5.0 (because it is lower of the two).

5 Ways to Minimize Bluetooth Latency

Source: Samsung

1. Stay within range of the Bluetooth device

We have learned that the distance between the source device and the receiver device can affect the performance of Bluetooth. The first step to minimizing Bluetooth lag should be to make sure your two devices are in close proximity to each other and there aren't a lot of physical blockages between them.

2. Disconnect and reconnect your Bluetooth device

Most often the reason for increased Bluetooth latency is a faulty connection. It's possible that your devices weren't properly connected when you paired them. Many Bluetooth devices also experience lag when left connected for a long time. In such cases, just disconnect and reconnect your Bluetooth devices to fix the problem. If disconnecting and reconnecting does not resolve the Bluetooth latency issue, you can also try unpairing your device and then re-pairing it.

3. Use another codec

As we have learned, it is important to match the codec of the source device and the Bluetooth device, otherwise the configuration will revert to the oldest Bluetooth codec available, which is subject to audio lag. While most modern operating systems are smart enough to select the appropriate codec themselves, there are ways to force your device to use a specific codec for a particular device.

Although Apple doesn't let you select a codec manually, you can on Android. On Android smartphones, enable Developer options in the settings, then select the appropriate option under the Bluetooth audio codec setting. To check the type of codec supported by your Bluetooth headphones, check the device's specifications page.

4. Try using Bluetooth 5.0 (and above) devices

Bluetooth 5.0 is nothing new. However, we still haven't upgraded to all devices with Bluetooth 5.0. One of the reasons we recommend using a Bluetooth 5.0 (and higher) device is that the latest Bluetooth introduces a new technique to minimize audio lag called Audio-Video Sync (or A/V Sync). This technology allows your smartphone (or whatever device you're watching the video on) to estimate the amount of latency in your setup and add that delay to the video playing on the screen. This way it doesn't necessarily remove the lag, but it does ensure that the video and audio are aligned. However, it should also be noted that audio-video synchronization is unnecessary for things like games, as these applications are interactive and happen in real time.

5. Deactivate power saving mode

Source: Gadget Hacks

To extract extra battery life from our devices, we often use the battery saver option on our smartphones and other computing devices. However, using these options may increase audio delay as these power saving modes (most often) reduce your device's processing power. To ensure minimum delay, turn off power saving mode on your device before connecting it to a Bluetooth headset.

Why it may never go away

Source: Pocketnow

Bluetooth technology is advancing at a breakneck pace. We've reached a point where most smartphone manufacturers have removed the 3,5mm headphone jack from their devices as they provide a much more comfortable listening solution. Despite all the advancements, it should be noted that latency is an issue that cannot be completely eliminated, at least for now.

The whole process of converting audio data into a signal, transmitting and decoding will still be there, and it will cause some kind of delay. Additionally, most audio accessory makers now like to offer true wireless headphones, which have an added lag to ensure that the left and right headphones are in sync. Currently, there is no way to completely eliminate Bluetooth audio lag, but there are many ways to minimize it (see above).

This is by no means to say that Bluetooth devices are not useful. Although Bluetooth devices may not be replaceable in areas where "0 lag" is needed, technology always makes everyday use much more convenient. Do you think Bluetooth headphones offer better value for money than wired headphones despite a delay? Let us know in the comments section below!