Bluetooth Connectivity Score and Tests

Headphones

Bluetooth versions vary between headphones and come with a suite of features that improve the data rate of transmission, improve the battery life, or add additional codecs to reduce lag and latency. All Bluetooth standard versions support downward compatibility, which means that a smartphone running Bluetooth 5.0 will still work with headphones that are Bluetooth 4.2 and vice versa.

To test the Bluetooth version, we consult the headphones' documentation to confirm the Bluetooth version, whether through product manuals, specification sheets, or simply checking the box. If we can't confirm the Bluetooth version with the information provided with the headphones, we consult the vendor page of the retailer we purchased the headphones from to see if there is additional information online. If we still can't determine the official Bluetooth version, we report 'Unspecified'.

Multi-device pairing lets you connect your Bluetooth headphones to multiple devices with full, simultaneous functionality on each source. Bluetooth headphones with multi-device pairing can connect to a Bluetooth-enabled laptop and smartphone at the same time and play media as well as take calls/use the microphone on both devices simultaneously. Some headphones support partial multi-device pairing, which means they can play and control audio on one Bluetooth device and use the microphone to make phone calls on another.

Many gaming headphones also support multi-device pairing. However, they tend to support Bluetooth on one device and a wireless connection via a dongle on console. We indicate this kind of connection by stating, 'Bluetooth + Console/Non-BT Wireless'.

To test multi-device pairing, we attempt to pair and connect the headphones to two separate Bluetooth devices (currently two Android phones). We then test both media playback and microphone control channels on each device to ensure all channels work simultaneously on both devices. For headphones with a wireless dongle, we'll additionally connect them to a console via their dongle and use Bluetooth to connect them to our Android phone. We repeat the same media playback and microphone control check on each device.

If you have an Android device like a Google Pixel or Samsung Galaxy S phone, then you can benefit from quick pairing, which is designed to make pairing your headphones to your device easier. That also means that you don't need to open your Bluetooth settings and manually select these headphones. There are a few kinds of quick pairing, such as NFC (Near Field Communication) pairing, Google Fast Pair, and Bluetooth Swift Pair. For this test, the headphones either 'Yes', support quick pairing on Android, or 'No'. The text will tell you what's supported.

To test for this, we check the manufacturer's documentation and confirm quick pairing implementations with our Android device.

Quick pair lets you easily pair your headphones with your iPhone or iOS device. Headphones with an H1/H2 or W1/W2 chip, like the Apple AirPods Pro (2nd generation) Truly Wireless, are designed to easily pair with your iOS device. Like Quick Pair (Android), there are only two outcomes for this test: 'Yes' or 'No'.

To check for quick pairing, we check the manufacturer's documentation and confirm quick pairing with our iOS device.

This is the headphones' range when in direct line of sight with the Bluetooth source. This is important if you're listening to audio or watching a video and don't want to sit very close to your audio device, such as a PC or the TV in your living room.

We test for this by connecting the headphones to the same Bluetooth-enabled phone in a large open area, like a parking garage. We then evaluate the distance with a measuring wheel until the wireless connection is too weak to reliably transmit audio without any drops or issues in quality. This distance is also measured three times and then averaged to obtain the line of sight range.

Base latency refers to the default sub-band coding (SBC) that most wireless headphones use when connecting via Bluetooth. This typically occurs if the headphones do not have any additional codecs like aptX or AAC. The headphones will also default to SBC if you're trying to use a codec not supported by both Bluetooth devices.

Typical SBC latency ranges between 150 to 250 ms.

AptX is a proprietary codec by Qualcomm (previously CSR) that improves audio quality and bit rate efficiency. This means headphones with aptX sound a bit better and less compressed when playing audio wirelessly. They also have a bit less latency than SBC.

Typical aptX latency ranges between 50 to 150 ms.

AptX Adaptive is a codec that automatically adjusts its bitrate between 279 to 420kbps based on what you're playing. It's backward compatible with aptX and aptX HD in stereo headsets.

While you'll experience high audio quality via this codec, it also tends to have 200 to 300 ms of latency. This isn't really a problem if you're just streaming audio, though.

As previously mentioned, AptX Adaptive is a codec that automatically adjusts itself to the bitrate between 279 to 420kbps based on what you're playing. When you're watching videos or doing something that requires less audio lag, the codec will switch into low latency mode.

This codec tends to have 50 to 100 ms of latency, so while its latency isn't virtually eliminated like most analog connections, it's still low enough that you'll be able to enjoy your content without significant lip sync issues.

LDAC is a proprietary codec created by Sony. It uses lossless and lossy compression for streaming high-resolution audio. While you'll find this most commonly in Sony headphones, there have been other adopters of this codec, like Anker, Audeze, and Shure. Usually, to play LDAC from your smartphone or other device, you'll need to see if the feature can be enabled in your device's settings.

This codec has a variable bitrate with three settings: 330kbps, 660kbps, and 990kbps (with an advertised maximum bit depth and frequency of 24-bit/98kHz for high-quality audio). However, reaching max bitrate depends on the stability of your connection, as the codec can control the bitrate based on the network connection. You're likely to start at 660kbps rather than the highest setting, though.

There are a couple of downsides to this codec. For instance, it's not supported on Apple devices. In addition, using LDAC can reduce your battery life. It tends to have high latency, too—between 200 to 300 ms—but this won't really impact you if you're only streaming audio.

This track is the combined output of the reference audio track and the tested headphones' track. It allows you to hear the latency for yourself.

This lets you know what codec we used for our recorded latency file. We select the codec that users are most likely to use.

AAC (Advanced Audio Coding) is the successor to MP3 and is the default codec for iOS devices, though other devices support it as well. It's expected that its latency should be as low as SBC. However, we can't test AAC latency due to the complexity of testing it on our setup. You can read more about it in our R&D article.

We check for AAC support by pairing the headphones to a Mac computer and checking within the console app.