What is aptX? Understand the importance of the codec for your Bluetooth headset

aptX is a codec present in many smartphone models and wireless devices such as Bluetooth speakers and headsets. In its traditional version, it is capable of playing audio files of up to 384 Kb/s (Kilobits per second), 48 kHz frequency, and 16-bit resolution. However, in recent years, Qualcomm has released new versions that decrease latency (such as aptX LL) and support higher quality sound files (such as aptX HD).

However, to take advantage of them, both the source and the headset or speaker must be compatible with the version. Below you can learn more about aptX technology and how it can improve the sound quality of your Bluetooth device.

What is a codec and what is aptX used for?

aptX is a codec developed for Bluetooth technology. In short, codecs are software programs that use algorithms to create and play digital audio files. Different codecs use different mathematical formulas to make the files have the best sound quality while taking up as little space as possible. Extensions such as MP3, AAC, and FLAC, for example, are all created from codecs.

When it comes to Bluetooth, there is an additional issue. This is because wireless technology was not originally intended to transmit large files, let alone play music in real-time. The first Bluetooth devices in history were simple headsets used to make phone calls.

Sennheiser HD 350T

This only changed with the implementation of Advanced Audio Distribution Profile technology, also called A2DP, which reserves a larger portion of the bandwidth just for transporting audio files. With this was created the standard codec SBC, which is available on every Bluetooth device.

However, SBC is not exactly the best possible codec. Developed in 2003, it was designed to consume as little battery power as possible – which directly impacts the sound quality. Therefore, other companies have developed their Bluetooth codecs to better utilize the available bandwidth space. Besides Qualcomm’s aptX, other commonly used codecs are AAC, LDAC, and LHDC.

READ:  Is Onkyo HT-S5910 any good? See the price and technical sheet on the home theater

What are the features of aptX?

aptX, named after audio processing technology, is older than Bluetooth itself, having been developed in the 1980s at Queen’s University Belfast in Northern Ireland. The original codec was even used in the audio digitization of Hollywood productions such as “Jurassic Park” and “Saving Private Ryan”.

Only in 2009 did aptX become a codec for Bluetooth connections. The first version, which is the same one used today, is capable of playing files with up to 384 Kb/s, 48 kHz frequency, and 16-bit resolution. In technical terms, it is a little better than SBC, which plays files up to 345 Kb/s. However, according to Qualcomm, aptX is more efficient and can compress files more effectively, compromising less sound quality.

aptX

In addition, the codec has a low latency of up to 60 ms (milliseconds), because it decodes the audio in real-time – that is, while it is still playing. In 2012, Qualcomm released an even faster version, reaching a range of 30 ms, called aptX LL (low latency).

What are the versions of aptX?

After being released in 2009, aptX has gained four other versions. LL is designed to offer the lowest possible latency, which makes it ideal for those who need synchronization between picture and sound, like in games or movies. This version plays files up to 352 Kb/s, 48 kHz frequency, and 16 bits.

In 2016, the aptX HD version was released. With this, the codec became capable of playing files with up to 570 Kb/s, 48 kHz frequency, and 24-bit resolution. Although it does not play lossless audio, the upgrade significantly improved the sound quality.

READ:  LG Tone Free T90, T60, Fit TF7, and Fit TF8: self-cleaning case and great sound promise
aptX

In 2018, the company released aptX Adaptive. It is a mixture of the other two previous codecs: in a normal environment, it is capable of playing files up to 420 Kb/s, 96 kHz frequency, and 24 bits. But if necessary, it lowers the bitrate to 276 Kb/s to reduce latency.

Finally, in 2021, Qualcomm announced the aptX Lossless codec, which will be the first to play CD-quality audio via Bluetooth. According to the company, it will be possible to transmit files with up to 1.4 Mb/s (megabit per second) with a frequency of 44.1 kHz and 16 bits. So far, no products have been released with this technology.

Who are aptX’s competitors?

As we mentioned earlier, SBC is the codec that is present in all Bluetooth audio products – from speakers to smartphones. It is designed to be the lowest common denominator between electronics: for example, if a TV uses one proprietary codec and the headset uses another, they can still connect through SBC.

Despite being technically inferior to its competitors, SBC is not that bad. With a playback capacity of up to 345 Kb/s, it is possible to listen losslessly to the entire Spotify catalog in maximum quality, which plays files of up to 320 Kb/s, in theory.

AAC is the codec exclusively for Apple devices such as iPhones and iPads. It is capable of playing files with up to 320 Kb/s, a frequency of 44.1 kHz, and 24 bits. Although the bit rate is lower than SBC, it has a more advanced compression and decompression system – so the sound has less loss compared to the standard codec. On the other hand, it also consumes more battery power.

READ:  Apple AirPods (3rd generation): Features, Reviews, and Price

Sony also has its codec, LDAC. It can play back files of up to 990 Kb/s, 96 kHz, and 32 bits. And finally, there is LHDC, developed by Savitech, which can play audio at up to 900 Kb/s, 96 kHz, and 24 bits.

Which products are aptX compatible?

Edifier X3

If you have a smartphone with a Qualcomm chip, it is almost certain that it has the aptX codec installed. If not, the aptX website has a very extensive list of phones that are compatible with the technology. However, the aptX HD and Adaptive versions are usually only present in more expensive models.

As for the headsets, there are also a variety of options on the market. One of them is the Edifier X3, which can be found starting at $33.35 on Amazon, and has a battery life of six hours.

The aptX HD codec is only available in premium devices, such as the Sony WH-1000XM3, which starts at $313.91 on Amazon. The Bluetooth headset stands out for its sound quality and features such as active noise cancellation.

Xiaomi Flipbuds Pro

Among those with aptX Adaptive, the highlight is the Xiaomi FlipBuds Pro headset, which also features Snapdragon Sound technology – a suite of Qualcomm technologies that deliver cleaner sounds and less latency.

This post may contain affiliate links, which means that I may receive a commission if you make a purchase using these links. As an Amazon Associate, I earn from qualifying purchases.

Advertisment

Want to stay up to date with the latest news?

We would love to hear from you! Please fill in your details and we will stay in touch. It's that simple!