Bluetooth is now ubiquitous and the de facto standard for wireless audio transmission. The first official version became available on consumer devices in 1999, and many iterations have come since then, with the latest 5.3 version coming out in July, 2021.
In addition to the different versions, Bluetooth has many available codecs (short for code/decode or compression/decompression depending on whom you cite). Without going on an unnecessarily technical and irrelevant tangent, a codec basically compresses an audio file (by removing superfluous data in a way that a human ear can’t detect) down enough so that it’s small enough to be wirelessly transmitted.
The lifecycle of budget headphones and earbuds has become quite fast, so most current wireless headphones have Bluetooth 5.0+, but there are still some current and popular products that have Bluetooth V4, and if any given product you might have is at least a few years old there’s a decent chance it has Bluetooth v4. Bluetooth v3 and lower has essentially been deprecated at this point, and we’ve never seen it on any of the audio products we’ve looked at or reviewed, so it doesn’t warrant discussion.
We’ve seen claims that the newest version of Bluetooth or some fancy “hi-res” codec will improve sound quality, and maybe you’re thinking of retiring a pair of wireless headphones – but does it? and should you?
Does Bluetooth 5 improve sound quality over Bluetooth 4?
No – Bluetooth 5 doesn’t do anything to improve actual sound quality. Most of its improvements are practical and quality of life related:
- battery efficiency, which means longer charges
- signal distance
- signal stability and reliability, which means less buffering and/or cutting out
- latency, which doesn’t matter when listening to music, only when audio needs to sync with a video, game, etc.
Bluetooth v4 supports up to 1bm/s of bandwidth, which is still plenty for the modern codecs and audio file types that 99.9% of people will use with their wireless headphones and paired devices.
In fact, none of the major audio files or codecs have actually changed with Bluetooth v5, which is to say you’ll be using the same technology as you would with v4 thus v5 obviously has no way of actually sounding better. So, if any of the previously listed improvements appeals to you, then that’s definitely a legitimate reason to upgrade Bluetooth v4 to v5. But no, the quality of your music isn’t going to improve.
Does any specific Bluetooth codec improve sound quality over others?
And what about that fancy codec that claims it can handle “hi-res” audio at higher bandwidth, and thus improve sound quality? Odds are, again, almost certain that you’re not actually using a hi-res (and high file size) lossless audio file on your device. If an audio file is already in a compressed file format that’s supported by both the device and the wireless headphones (it probably is if you’re using any common source like a smartphone or laptop), then the Bluetooth codec will just not do anything to the file and just transfer it as is.
Let’s say, for hypothetical arguments sake, that you’re listening to an ultra hi-res audio file (that’s 30 times larger than the standard AAC or mp3 version) through a premium music streaming service like Amazon HD, transmitting it via Bluetooth to a headphone amp with an onboard dac, which is then connected to a $500+ pair of wired headphones. Then you could, maybe, hear a noticeable loss in sound quality rather than if you just plugged your headphones right into the source, but obviously no one’s doing anything of that sort.
The actual headphones themselves – how well they’re built and how well they fit you and how much you like their given style – is what’s going to noticeably affect sound quality, and thus what you should pay attention to if that’s what you care about.