What is aptX? Cutting through the clutter of Qualcomm’s Bluetooth codecs - Beritaja

You mightiness not cognize it, but erstwhile you spell retired and bargain a group of Bluetooth headphones, earbuds, aliases a Bluetooth speaker, you’re besides inadvertently choosing The Bluetooth codec that those devices will usage erstwhile you link them to your phone, computer, aliases different device. This codec compresses audio signals for businesslike transmission and past decompresses them for playback.

But not each codecs are created equal. Since Bluetooth has constricted bandwidth, The prime of codec Can beryllium crucial. That’s wherever Qualcomm and its industry-leading “aptX” codecs travel in. With 5 different versions of The technology, each offers different levels of capacity qualities that Can heighten sound, trim latency, and more.

Confused? We get it — it Can beryllium a lot. Fortunately, you’ve travel to The correct place. We’re present to thief you understand much astir aptX (pronounced “ap-tex”) truthful you Can make a better-informed determination erstwhile buying audio products.

What is aptX?

First, a speedy primer connected why we person Bluetooth codecs in The first place. Because The wireless tube that Bluetooth creates betwixt devices is beautiful constrictive erstwhile compared to different tech for illustration Wi-Fi, it can’t ever accommodate digital euphony in its original format. So codecs are employed to compression audio until it’s mini capable to fresh down that pipe.

Ever since 2003, erstwhile The expertise to watercourse stereo sound complete Bluetooth was launched, sub-band coding (SBC) has been The default codec utilized to do that job. If you ain a Bluetooth audio device, whether it’s a phone, a speaker, aliases a group of wireless headphones, it supports SBC. Having a default codec is awesome — it’s what ensures that each Bluetooth audio devices will activity together.

The problem is that contempt The truth that SBC is Can of delivering very bully sound quality, galore manufacturers hobbled its information complaint in The early days of Bluetooth audio arsenic a measurement of ensuring that dropouts wouldn’t happen. After all, you mightiness beryllium consenting to put up pinch less-than-perfect sound. But audio that cuts retired each The time? Forget astir it. That earned SBC a spot of a bad rap. It besides didn’t thief that SBC suffered from important latency.

At this point, The aptX codec had already been in usage in a assortment of settings, for illustration filmmaking and broadcast, erstwhile The institution that owned it realized it had The imaginable to activity arsenic an replacement to SBC. AptX’s cardinal benefits complete SBC are higher-quality audio and little latency — in different words, you could expect amended sound, and if that sound was attached to video, you could expect amended synchronization betwixt what you saw and what you heard. The aptX suite of technologies yet was purchased by Qualcomm in 2015.

Apple’s AirPods Max do not support aptX codecs Simon Cohen

The compatibility problem

The problem pinch each replacement codecs (including aptX, AAC, LDAC, etc.) is that they require support connected some The root (a phone, computer, aliases different devices) and The descend (speaker, headphones, earbuds) in bid to work.

If your telephone Can do aptX, but your headphones can’t, The Bluetooth relationship will revert to SBC, aliases perchance AAC, if AAC is supported connected some devices. In The Android world, this is seldom a problem. AptX has been included in Android almost since The get-go. As agelong arsenic your audio merchandise useful pinch aptX, that’s what The 2 gadgets will use.

But to this day, Apple, 1 of The biggest smartphone makers in The world, refuses to see immoderate non-SBC codec isolated from AAC connected its iOS and iPadOS devices.

Are aptX’s benefits real?

Initially, galore merchandise reviewers were impressed by aptX, and felt that it delivered improved audio value complete non-aptX-equipped gear. You whitethorn still spot immoderate reviewers, including folks who constitute for , complain erstwhile wireless headphones aliases earbuds deficiency aptX.

This is partially because aptX uses a different shape of lossy compression than SBC aliases AAC — The SBC replacement favored by Apple —  and immoderate group for illustration The measurement it sounds. But it’s besides thing of a holdover from The days erstwhile Bluetooth bandwidth was smaller and SBC was often forced to tally astatine little spot rates, whereas aptX ever runs astatine a fixed 352 kilobits per second (Kbps).

AptX’s nondestructive shape of compression was particularly beneficial in those early days erstwhile astir group were listening to integer euphony in MP3 format. SBC and AAC usage psychoacoustic models of compression, which Can make already heavy compressed files for illustration MP3 sound worse, whereas aptX does a amended occupation of preserving The specifications in these files.

These aforesaid benefits Can still beryllium appreciated today, depending connected The source.  If you’re streaming Spotify utilizing a free account, The champion imaginable audio mounting only delivers 160 Kbps, which intends a batch of compression has already been applied.  And since Spotify streams in The Ogg Vorbis format, which can’t beryllium utilized complete Bluetooth, your telephone has to decode and past re-encode that watercourse into SBC, AAC, aliases (if your instrumentality supports it) aptX.

On The different hand, if you’re starting pinch lossless, CD-quality sound, you whitethorn not perceive overmuch of a quality betwixt codecs astatine all.

Over time, aptX has evolved from a azygous codec to an full family of codecs, each pinch its ain strengths, weaknesses, and compatibility requirements. Latency is simply a peculiarly thorny situation for Bluetooth audio because location are truthful galore links in The concatenation betwixt The clip erstwhile a sound is generated by a instrumentality for illustration a telephone and erstwhile it is yet turned into a sound you Can perceive connected your wireless headphones.

AptX Low Latency

Depending connected your devices and their supported codecs, latency Can scope arsenic precocious arsenic 320 milliseconds. For euphony listening, this doesn’t matter astatine all, but for movies, YouTube, and especially gaming, it’s excessively long. AptX Low Latency (aptX LL) reduces latency dramatically, down to astir 38 milliseconds, which makes it imaginable to respond quickly in fast-paced games. AptX LL is constricted to lossy, 16-bit audio, truthful it won’t beryllium anyone’s first prime for captious euphony listening, but it makes wireless headphones a genuine replacement to wired headphones erstwhile a accelerated relationship is needed.

There is simply a catch, however. Like each different codecs, to get The use of aptX LL, it needs to beryllium supported connected some ends of The wireless audio connection. Finding headphones and earbuds that person aptX LL is comparatively easy. But location are nary smartphones aliases tablets that connection aptX LL.

It each comes down to really phones usage their antennas. If we only ever streamed section files from our phones, aptX LL would astir apt activity conscionable fine. But since The days of copying MP3 files from our computers to our phones are fundamentally over, it intends antennas request to contend pinch Bluetooth and Wi-Fi simultaneously, making reliable implementation of aptX LL very hard, aliases impossible; it’s efficaciously gone from The mobile world.

So moreover though aptX LL headphones are readily available, The only measurement to return advantage of their low-latency capacity is to usage a dedicated aptX LL transceiver, usually in The shape of a USB dongle that Can plug into a machine aliases crippled console.

AptX HD

SBC, AAC, and aptX are The most-supported Bluetooth codecs around, but each 3 are typically constricted to lossy compression astatine 16-bit/44.1kHz, pinch spot rates that seldom spell supra 352 kbps. Under astir conditions, this delivers a adjacent approximation of CD-quality audio, assuming you’re starting pinch a high-quality root for your audio.

Still, it was felt that greater value could beryllium achieved if The supported spot depth, sample frequency, and spot rates could beryllium improved, truthful aptX HD was born. With support for audio astatine up to 24-bit/48kHz, and pinch a boosted, fixed information complaint of 576 Kbps, it still uses lossy compression, but it’s Can of preserving much detail, peculiarly erstwhile you’re streaming euphony that starts disconnected arsenic lossless, 24-bit audio connected your device. Some group moreover see aptX HD to beryllium a hi-res audio codec.

AptX HD’s encoding improves connected aptX’s signal-to-noise ratio (SNR), arsenic good arsenic full harmonic distortion (THD+N), which are 2 different areas that impact really accurately sound is reproduced. AptX HD is besides backward compatible pinch classical aptX-capable headphones and earbuds — it Can revert backmost to classical aptX erstwhile these products are detected, without resorting to SBC.

But location are 2 downsides to aptX HD. The first is that it uses a fixed information rate. If your telephone and headphones can’t support a 576 Kbps connection, The reliability of The audio Can suffer.

The 2nd is that, owed to that higher information complaint requirement, it can’t beryllium utilized connected “true” wireless earbuds (where The earbuds aren’t connected by a cable) because The earbuds request immoderate of that bandwidth to pass pinch each other. Despite that, immoderate companies person tried to make it activity — 1 notable illustration is The Bowers & Wilkins PI7. Some reviewers person enjoyed The result, but erstwhile tried them, we recovered The Bluetooth relationship to beryllium highly unstable astatine thing but The shortest distances.

You’ll still spot plentifulness of wireless headphones that connection aptX HD — moreover models that debuted in 2022 — but The exertion has been supplanted by Qualcomm’s newer aptX variant, aptX Adaptive.

aptX Adaptive

The Sonos Ace headphones support aptX Adaptive Simon Cohen

Bluetooth wireless connections are notorious for their up-and-down nature. If you unrecorded in The countryside and clasp your telephone in your hand, little than a ft from your headphones, pinch your Wi-Fi and cellular functions turned off, you’re astir apt getting a really bully relationship astatine adjacent to The maximum information complaint that Bluetooth Can support because you’ve heavy reduced imaginable sources of interference.

But for astir of us, this is The exception, not The rule. Changing distances betwixt devices and interference from a immense assortment of different power frequencies Can dramatically impact The value of Bluetooth links, making immoderate codec that operates astatine a group information complaint (like aptX and aptX HD) susceptible to mediocre performance.

A scalable codec that Can set its information complaint in real-time Can thief lick The interference problem. If you’ve ever watched Netflix and noticed really The image value sometimes goes from crisp to a spot pixelated, past backmost to crisp again, you’re seeing Netflix’s scaling astatine activity arsenic it responds to changes in your net relationship speed.

AptX Adaptive supersedes aptX and aptX HD (yet is still backward compatible pinch both) and has The expertise to ramp its information complaint from 110 Kbps to 620 Kbps arsenic nexus conditions change.

By default, aptX Adaptive uses The aforesaid 24-bit/48kHz solution of aptX HD, but it Can besides spell higher, up to 24/96, giving it The aforesaid maximum solution arsenic Sony’s LDAC codec. It’s besides a much businesslike codec, according to The company, which says it Can execute The aforesaid value arsenic aptX HD astatine conscionable 420 Kbps, arsenic compared to HD’s fixed 576 Kbps. But existent to its name, it’s not conscionable a 24-bit codec. Adaptive Can besides run in 16-bit/44.1kHz mode erstwhile required.

The codec’s adaptive quality goes beyond spot depths and sample frequencies. It Can besides respond to The benignant of audio activity you’re engaged in. When it detects that you’re gaming, it Can automatically move to a low-latency mode, which, nether optimal conditions, Can lucifer The capacity of aptX LL. If it detects that you’re connected a call, it Can set its settings truthful that you and your caller are some getting high-quality audio (aptX Voice).

If this sounds for illustration a best-case scenario, it is, but arsenic is often The case, location are respective caveats.

Unlike aptX and aptX HD, which Can beryllium enabled utilizing package connected The root broadside of The equation (which apt explains why they’re included pinch The Android operating strategy sloppy of which telephone you buy), aptX Adaptive requires The usage of Qualcomm’s chips connected some The root and descend devices.

You Can nary longer bargain an Android telephone and presume it supports aptX Adaptive. Google’s Pixel phones are a bully example. Even The newest Pixel 8 series doesn’t have aptX Adaptive built-in.

Qualcomm has besides fixed manufacturers tremendous discretion complete which aptX Adaptive features they Can enable. For example, The expertise to do hi-res audio astatine 24/96 was added to aptX Adaptive in 2020, and The shaper must move it on. The aforesaid point goes for low-latency and high-quality sound calls. Some companies will determine not to do that. Unfortunately, The only measurement to cognize if your devices will present a circumstantial characteristic is if they are listed in The specifications for some products.

For instance, some The Sennheiser Momentum True Wireless 3 earbuds and The Master & Dynamic MW75 headphones support aptX Adaptive, but The MW75 is presently constricted to 24/48, while The Sennheisers will spell up to 24/96 — but again, only if The root instrumentality besides supports it.

On The immense mostly of phones, you cannot spot The information complaint your 2 devices are using, making it difficult to cognize if you’re getting The champion imaginable audio value aliases really changing your distances aliases locations is affecting that link.

AptX Lossless

So far, each of these Qualcomm codecs usage lossy compression, which removes immoderate of The original accusation in an audio file. In an perfect world, codecs would run losslessly — compressing The record size without affecting audible bits.

As The sanction suggests, aptX Lossless promises a bit-for-bit cleanable transportation of CD value astatine 16-bit/44.1kHz — a benignant of Holy Grail for wireless sound — thing that has traditionally been intolerable because of The inherent limitations of Bluetooth bandwidth.

Qualcomm claims to person flooded this limitation by combining aptX Adaptive’s expertise to run astatine 16-bit/44.1kHz and Qualcomm’s Bluetooth High-Speed link, which Can present The 1 Mbps spot complaint needed to do lossless audio.

The institution says it has seen aptX Lossless activity moreover astatine distances of 15 feet aliases much in congested wireless environments. But since nexus value Can beryllium difficult to predict, aptX Lossless will standard according to real-time conditions, going each The measurement down to 140 Kbps if needed. That won’t beryllium anyplace adjacent to bit-perfect lossless audio, but you won’t get disconnected.

At The apical of The information complaint scale, users Can determine if they want The codec to present 16/44.1 lossless audio aliases aptX Adaptive’s 24/96 lossy audio.

Getting aptX Lossless to activity correctly requires galore technologies to run in lockstep pinch 1 another, truthful Qualcomm only makes aptX Lossless disposable connected devices that person passed its Snapdragon Sound certification program.

How do you cognize if you’re getting aptX’s velocity benefits?

You would deliberation that The costly brace of headphones and/or your telephone would travel pinch each The devices you request to way and corroborate whether you’re getting each The benefits of this precocious tech. Alas, it is not so. As we constituent retired in item in our fantabulous explainer connected wireless audio’s missing speedometer problem, users person to trust connected The telephone aliases headphone makers including an app aliases immoderate different intends of showing you The sound value you’re really getting.

Some streaming euphony apps, for illustration Amazon Music, do show immoderate of this information, and location are outer devices specified arsenic DACs that bespeak things for illustration The codec you’re using, but for The astir part, nailing down The capacity of your full audio-quality way is unluckily not easy.

Snapdragon Sound

Qualcomm

AptX Adaptive ushered in a caller level of codec capabilities, but arsenic we elaborate above, galore of those capabilities are astatine The discretion of manufacturers. That creates a problem: How do you cognize what you’re really getting erstwhile you bargain a merchandise that advertises itself arsenic supporting aptX Adaptive?

To thief reside this, Qualcomm created Snapdragon Sound. Contrary to what it sounds like, Snapdragon Sound isn’t a caller exertion aliases codec. Instead, it’s a certification, 1 that guarantees that The pursuing aptX Adaptive features will activity erstwhile 2 Snapdragon Sound devices are utilized together:

• 24-bit/48kHz
• 24-bit/96kHz
• Low-latency mode erstwhile gaming
• AptX Voice (super wide set voice) erstwhile connected a call
• Qualcomm Bluetooth High Speed link

Technically speaking, there’s nary concealed condiment here. Any shaper that uses Qualcomm’s S3 aliases S5 chips Can present each of these features if they choose. But you’ll only spot The Snapdragon Sound explanation connected a merchandise if it supports them each and if The instrumentality shaper has submitted their merchandise to Qualcomm to acquisition its verification tests.

The intent down The Snapdragon Sound programme is to fto buyers respire a sigh of relief, knowing that arsenic agelong arsenic they spot The explanation connected their wireless audio devices and their phones, everything will “just work.” However, The database of features that Qualcomm includes in its Snapdragon Sound explanation will not stay static, moreover though The marque will look The same.

For instance, you’ll announcement that The database of features supra does not see aptX Lossless. That’s because The first meaning of Snapdragon Sound was developed earlier Qualcomm was fresh to merchandise aptX Lossless. As of 2022, lossless is included in Snapdragon Sound, and that’s wherever The worth of a azygous explanation starts to falter.

If your Snapdragon Sound wireless earbuds were 1 of The earliest models, for illustration The Oddict Twig Pro, they astir apt don’t support aptX Lossless, and can’t beryllium updated to support it, moreover if you’re utilizing them pinch a Snapdragon Sound telephone that does support lossless.

It doesn’t extremity there. Snapdragon Sound’s features will apt alteration each year. Among its newest devices is head-tracked spatial audio, which is slow arriving connected newer supported devices. Bluetooth LE Audio compatibility, little latency for gaming, and support for in-game back-channel sound are besides newer additions. Snapdragon Sound is besides expanding aptX Lossless’ sampling rates from 44.1 to 48kHz.

Buyers will request to do their homework erstwhile again. Snapdragon Sound certification from Qualcomm indicates that features and capacity person been tested and certified. However, it whitethorn not reliably bespeak which circumstantial features you Can use.

Editor: Naga



Read other contents from Beritaja.com at