As wi-fi headphones and, particularly, wi-fi earbuds have grown in reputation, so has the tech jargon that goes together with these gadgets. Wi-fi charging, Bluetooth multipoint, put on sensors, ANC and transparency, IPX rankings, spatial audio … it’s sufficient to make your head spin.
Whereas most of those phrases relate to options which might be fairly straightforward to grasp, there’s one time period that’s assured to confuse: Bluetooth codecs.
What are they? And why must you spend any time fascinated by them? We’ll break it down with a plain-language explainer in order that the following time you learn a headphone evaluation that criticizes the dearth of aptX, AAC, or LDAC assist, you’ll know what the reviewer is speaking about. However extra importantly, you’ll know why it’d (or may not) matter to you.
Let’s get into it.
What’s a Bluetooth codec?
Bluetooth, as a wi-fi expertise, has historically been pretty restricted by way of bandwidth. Every new model of Bluetooth (we’re as much as model 5.3 as of 2022) provides a bit extra bandwidth than its predecessor, but it surely’s nonetheless nowhere close to as capacious as, say, Wi-Fi. (Neither is it meant to be.)
As a result of some sorts of digital audio might be too large to be streamed in real-time over that restricted bandwidth, it must be re-packaged to suit. If Bluetooth didn’t try this, while you hit play in Spotify it might take 10 seconds or longer earlier than you heard something in your wi-fi headphones. Bluetooth codecs are the important thing to that repackaging and streaming course of.
The phrase codec, by the way in which, is a portmanteau for encoding and decoding, which is geek-speak for packaging and unpackaging.
Why is there a couple of kind of Bluetooth codec?
As with all issues technological, enhancements get revamped time as we get higher at creating software program and {hardware}. When wi-fi stereo headphones first appeared, there was just one Bluetooth codec: SBC, or sub-band codec. And to at the present time, in case your telephone, pc, headphones, or earbuds solely helps one codec, it’s SBC.
SBC is dependable and at all times will get the job accomplished, but it surely wasn’t constructed for high-quality or low-latency purposes. Within the early 2000s, when stereo audio was added to Bluetooth, the highly-compressed MP3 file format nonetheless reigned supreme. Right now’s music streaming companies hadn’t arrived, and virtually no person was speaking about the necessity to assist lossless music in 24-bit/96kHz. Cellular gaming nonetheless was a few years from turning into mainstream.
However as these eventualities began to creep nearer to heart stage, it grew to become obvious that we would have liked new codecs that would take us past SBC’s limitations. We now have no less than 10 Bluetooth codecs that exceed SBC not directly. Some supply decrease latency (the time it takes from when your gadget makes a sound to when your headphones allow you to hear that sound), some supply larger high quality audio, some are constructed to be extra power environment friendly, and a few attempt to perform a little little bit of the whole lot. And as of 2022, the listing of beyond-SBC Bluetooth codecs is astonishingly lengthy:
- AAC
- aptX
- aptX Low Latency (LL)
- aptX HD
- aptX Adaptive
- aptX Lossless
- LDAC
- LHDC/LLAC
- LC3
- MQair
- Samsung Scalable Codec (SSC)/Seamless Hello-Fi Codec
Do I have to care about Bluetooth codecs?
In case your head is now swimming, take a deep breath, as a result of we’ve acquired excellent news: Until you could have a really particular want, such as you’re a aggressive gamer who wants ultra-fast response occasions, otherwise you’re an audiophile looking for the absolute best sound high quality, you may in all probability cease studying.
Although some wi-fi options can’t be absolutely appreciated except you employ a number of of the precise codecs listed above, the underside line is that every one Bluetooth gadgets assist SBC. So don’t fear — even when you don’t know the distinction between these codecs, your chosen audio merchandise will nonetheless work completely nicely collectively.
How do Bluetooth codecs work?
Because the phrase codec implies, when you encode data, you want to have the ability to decode it on the opposite finish, and codec compatibility is vital. For a codec to work, it must be supported on each the sending and receiving ends. In case your earbuds assist aptX, as an illustration, however your telephone doesn’t, you gained’t be capable of use the aptX codec.
When two Bluetooth gadgets join, they relay which codecs they assist. Typically, they are going to default to the best high quality mutually supported codec. So if two gadgets assist aptX, they’ll use that as an alternative of SBC.
But when they’ll’t discover any widespread floor — e.g. one helps AAC however not aptX, and the opposite helps aptX however not AAC — they are going to fall again on good ol’ SBC.
That is the place I’ve some dangerous information for Apple followers. Your iPhone, iPad, Apple Watch, and to a lesser diploma your Macs, solely assist two codecs: SBC and AAC — neither of which helps hi-res, 24-bit audio, or low-latency operation.
Android house owners have extra choices, however beware: Android is a extremely fragmented world during which some handsets assist nearly all the most typical codecs, whereas others solely assist some. Google’s Pixel telephones are instance. They assist AAC, LDAC, and each aptX and aptX HD, however they don’t assist Qualcomm’s aptX Adaptive or aptX Lossless codecs.
What’s the distinction between Bluetooth codecs?
As we talked about above, ever since SBC, codecs have been trying to enhance sound high quality, latency, and power effectivity, or they carry out a balancing act that prioritizes one or two on the expense of the third.
You possibly can enhance latency and power effectivity by lowering the quantity of computational processing accomplished by a codec, however this typically results in drops in sound high quality. Conversely, when you attempt to ship higher-quality sound by utilizing extra bandwidth or performing refined computational audio processing, you run the danger of accelerating latency and degrading battery life.
Each of those eventualities are completely acceptable tradeoffs in the event that they ship the factor that you simply worth probably the most. That’s why now we have so many codecs.
Let’s check out the precise advantages provided by every Bluetooth codec.
Sub-band Codec (SBC)
Professionals:
- Supported by all Bluetooth gadgets
- First rate audio high quality for informal listening
Cons:
- Previous commonplace that hasn’t been optimized for newer gadgets
- Can undergo from longer latency
- Doesn’t assist hi-res or lossless audio
Superior Audio Coding (AAC)
Professionals:
- Default high-quality codec for all Apple gadgets
- Excellent audio high quality
Cons:
- Extra demanding of battery life due to better computational complexity
- Can undergo from poorer efficiency and longer latency, particularly on Android gadgets
- Doesn’t assist hi-res or lossless audio
Low Complexity Communication Codec (LC3)
Professionals:
- Designed to be extra power-efficient than different codecs
- Helps bit-depths as much as 32-bit
- Decrease latency than SBC and AAC
- Works with each listening to aids and wi-fi audio merchandise
Cons:
- Doesn’t assist hi-res or lossless audio
Qualcomm aptX household codecs (aptX, aptX HD, aptX LL, aptX Adaptive, and aptX Lossless)
Professionals:
- Decrease latency, much less computationally demanding than AAC, particularly aptX LL
- Extra power environment friendly than SBC
- Able to hi-res lossy audio as much as 24-bit, 96kHz (aptX HD, aptX Adaptive) or 16-bit, 44.1kHz CD-quality lossless audio (aptX Lossless)
- Probably the most broadly supported hi-res codecs on wi-fi headphones and earbuds (aptX HD, aptX Adaptive)
- Can modify on the fly to wi-fi and audio situations to keep up most high quality (aptX Adaptive)
- The primary (and at present solely) lossless Bluetooth codec (aptX Lossless)
Cons:
- Not supported on Apple gadgets
- Not at all times included by default on Android gadgets (aptX Adaptive/Lossless)
- May be complicated as a result of variety of totally different variations
LDAC
Professionals:
- Licensed for hi-res, lossy audio as much as 24-bit, 96kHz
- Included throughout the Android working system since model 8.0
- Supported by all of Sony’s flagship wi-fi headphones, earbuds, soundbars, and quite a lot of different audio gadgets
Cons:
- Not supported on Apple gadgets
- May be very power-hungry
- Generally excessive latency makes it a poor alternative for gaming/watching TV or motion pictures
- Headphone/earbud assist is much less widespread than aptX codecs
- Finest audio high quality requires quick distances between gadgets, with little or no interference from different wi-fi indicators
Low Latency Excessive-Definition Audio Codec (LHDC/LLAC)
Professionals:
- Licensed for hi-res, lossy audio as much as 24-bit, 96kHz
- Latency similar to aptX LL (LLAC)
- Accessible as a license-free possibility throughout the Android working system since model 10.0
Cons:
- Not supported on Apple gadgets
- Exhausting to search out on Android gadgets
- Low assist amongst main headphone makers
MQair
Professionals:
- Can theoretically assist an enormous array of audio qualities as bandwidth is obtainable as a result of it may well scale its bit price from lower than 220 Kbps as much as 20 Mbps
- Licensed for wi-fi hi-res audio
- It’s the one codec that may move alongside the MQA format wirelessly in order that it may be decoded by a set of headphones or earbuds
Cons:
- Not at present provided by any gadget producer
Samsung Scalable Codec (SSC) / Seamless Hello-Fi Codec
Professionals:
- Help for hi-res, lossy audio as much as 24-bit, 96kHz
- Can modify on the fly to wi-fi and audio situations to keep up most high quality (aptX Adaptive)
Cons:
- Solely obtainable while you use a appropriate Samsung telephone and Samsung earbuds
Bluetooth codec shopping for recommendation
So, when it comes proper all the way down to it, does any of this matter when selecting a brand new set of wi-fi earbuds or headphones, or probably a telephone? Sure and no.
Shopping for for sound high quality
One million variables go into wi-fi headphones. Issues like audio supply and driver dimension. Or design and supplies. The standard and energy of amplification. Using digital sign processing, high quality of digital-to-analog conversion, and the Bluetooth codec getting used. All of it components into sound high quality. However even then, the codec can be among the many least essential elements.
In different phrases, a hi-res codec like aptX Adaptive or LDAC can’t make a lower-quality set of cans sound higher, similar to placing high-octane gas in a minivan gained’t flip it right into a sports activities automotive.
So when you’re shopping for a finances set of earbuds or headphones — and also you’re not into gaming — codecs in all probability should not one thing you want to fear about. (And even suppose about, for that matter.)
I’ve listened to a number of sub-$100 earbuds that sound nice, regardless that they solely assist the base-level SBC codec.
However when you’re seeking to make an enormous funding in wi-fi earbuds or headphones to be able to get top-quality sound, codecs can and do make a distinction. After I’ve auditioned high-end headphones like Bowers & Wilkins Px7 S2, Grasp & Dynamic MW75, or the crazy-expensive Mark Levinson No.5909, after which alternated between an iPhone with AAC and an Android gadget with LDAC or AptX Adaptive, the distinction was instantly noticeable.
When utilizing these hi-res codecs, element, dynamic vary, and soundstage accuracy have been all improved. Would you discover the distinction when you have been listening to a low-bit price Spotify stream whereas commuting on a busy bus or practice? Not an opportunity. However if in case you have entry to hi-res, lossless content material through a streaming service or your personal private assortment of music, and you will discover a quiet place to relax, it’s the bees’ knees.
Shopping for for gaming efficiency
Avid gamers — significantly those that play rapid-action first-person shooters or different genres the place response velocity is crucial — have to be looking out for merchandise that provide low-latency codecs. Latency is measured in milliseconds and is greatest described because the time between an on-screen flash that you simply see, and the corresponding bang that you simply hear. The decrease that point, the quicker you’ll be capable of react to what’s taking place in your recreation.
The best possible option to cut back latency for gaming is to purchase a set of gaming headphones or earbuds that include their very own devoted wi-fi transmitter. This sidesteps the query of Bluetooth altogether, delivering latency as little as 20 milliseconds — we’re speaking 20-thousandths of a second.
However for a extra versatile answer, you may search for a set of wi-fi headphones that assist aptX LL. With delays measuring between 30-40 milliseconds, that is about as near a devoted wi-fi setup as you may get. However there’s a catch.
Although aptX LL is a Bluetooth codec, it’s not obtainable on telephones. It requires its personal devoted antenna as an alternative of the antennas in telephones which might be typically shared between Bluetooth and Wi-Fi connections. To get aptX LL, you’ll not solely want a set of headphones that assist it, just like the Sennheiser HD 450BT, but additionally a devoted aptX LL USB dongle which you can plug into your pc or recreation console.
For cellular gaming, decrease latency occasions are nonetheless potential — they merely gained’t get fairly as little as aptX LL. Search for headphones and earbuds that provide a gaming mode or a low-latency mode. Generally this implies the earbuds flip off any further sound processing they could be utilizing (which might in any other case improve latency), but it surely might additionally imply the earbuds are utilizing Qualcomm’s aptX Adaptive’s skill to mechanically modify to the content material you’re listening to. AptX Adaptive’s low-latency mode can cut back occasions to underneath 100 milliseconds — not as quick as aptX LL, however deal quicker than each SBC and AAC, which may run wherever between 150-300 milliseconds.
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