How do I get the best sound from Bluetooth headphones?
One of the most popular uses for Bluetooth is driving wireless headphones. Actually, “popular” might not be the right word: many people have reluctantly had to switch to Bluetooth headphones because their phone no longer has a traditional wired headphone adapter.
Unfortunately, Bluetooth isn’t ideal for enjoying music. The technology was originally designed for phone calls, and the creators were more worried about efficiency than sound quality. Accordingly, they chose an audio standard that required only lightweight encoding to provide comprehensible speech at low bit rates. This is the Sub-Band Codec, or SBC for short, and today it remains the baseline audio format for all Bluetooth devices.
SBC isn’t useless, but it can sound harsh and mushy compared to an uncompressed source. It also suffers from latency as high as a quarter of a second, so it’s not at all suitable for real-time gaming – and it won’t sync up properly with video content unless the host device adds a compensating delay.
The good news, however, is that you’re not necessarily stuck with SBC. Bluetooth allows you to use any audio-streaming codec that’s supported by both the host and device. The bad news is that there’s no standardisation here, so your options depend entirely on the hardware you’re using.
For Apple devices, the alternative is AAC – the same compression format that’s used by songs downloaded from Apple Music. Apple’s iPhones and AirPods use this by default, and although some quality is lost by re-encoding and re-decoding the music as it’s transmitted over the air, the sound is still much better than SBC. However, AAC support on Android is patchy and inconsistent, making AirPods a potentially risky investment for non-Apple users.
Android fans might be better off looking for aptX, a codec that’s similar to SBC but delivers higher audio quality and lower latency. The aptX HD variant is even better, promising “near lossless” sound with bit rates up to 576Kbits/sec. The only problem is that these codecs are proprietary to semiconductor manufacturer Qualcomm, so you can only switch to aptX if both your phone and headphones use Qualcomm Bluetooth chips.
Another alternative is LDAC. Unlike aptX this codec is open source, and supported by all modern Android devices. The downside of LDAC is that, having been originally developed by Sony, it’s mostly only supported by Sony headphones.
If all these different codecs confuse you, better times are on the way. The LE Audio profile, introduced in Bluetooth 5.2, includes a new default codec called LC3. This is a big improvement on SBC: the Bluetooth SIG claims that, in its own tests, listeners found LC3 encoding almost indistinguishable from the source material, even at lower bit rates than SBC. And since it’s a part of the core Bluetooth standard, LC3 should be universally supported by future devices. We’ve yet to see any headphones that use the new standard, but hopefully we won’t have to wait much longer. For now, if you want to see which codecs your Android phone supports, you can do so from the “Developer options” page in the Settings app. This is hidden by default; to make it visible, open the “About phone” page and tap repeatedly on “Build number”. Once you’re into the developer options, you should find an option entitled “Bluetooth audio codec”, which will bring up a menu from which you can browse the available audio formats and pick whichever one you prefer. Be warned, though: if you connect a pair of headphones or a speaker that don’t support your chosen codec, they’ll likely fall back to SBC.