AptX Bluetooth: What It Is In Phones, Smartphones And Headphones. What is Apt X headphone support What you need to appreciate aptX HD

The aptX HD protocol is designed to provide Hi-Res audio transmission over Bluetooth. Here's everything you need to know about it and how to use it.

Over the long journey, we have learned one wisdom: many people are willing to sacrifice sound quality for the sake of convenience. Take wireless headphones, for example. They can rarely compete with good wired ones, but they are much more convenient with them.

However, some time ago the pendulum swung towards the growth of quality. The most striking examples of this trend can be considered the revival of vinyl (this is where convenience is not at all talking about), as well as the growing popularity of Hi-Res audio. So, is there a way to combine usability and sound quality?

Qualcomm's developers are confident about this. Earlier this year, they introduced the aptX HD codec, which allows you to wirelessly stream music in 24-bit Hi-Res audio. Thus, Bluetooth enabled devices (such as portable speakers) can theoretically sound much better.

What's so great about aptX HD? How do I get it and what devices support it? We'll find out now.

What is aptX Bluetooth?

To understand what aptX HD is, you first need to remember the "classic" aptX. It is an audio coding algorithm created in the 80s and widely used by film makers and radio stations. Today, aptX is closely associated with Bluetooth, which is found in many computers, smartphones, AV receivers, and other consumer electronic devices.

The main advantage of aptX is its ability to transmit a full-band music signal in close to CD quality (16 bit / 44.1 kHz). This is "close" quality, not true CD quality, since aptX uses compression to reduce latency due to encoding and transmission. Classic aptX uses 4: 1 compression and the data transfer rate is 352 kbps.

What is aptX HD?

Now let's go directly to aptX HD. In essence, it is aptX, redesigned and improved to deliver higher quality music.

Its development was spurred by the rise in popularity of Hi-Res audio; it supports formats up to 24 bit / 48 kHz, the compression ratio remains the same (4: 1), and the data rate has increased to 576 kbps.

Whether the sound quality will be comparable to the transmission of Hi-Res signals over cable remains to be seen; but Qualcomm proudly waves the "better than CD" flag.

What do you need to rate aptX HD?

It takes a lot to use aptX HD. First of all, you need the right hardware. It is about the CSR8675 Bluetooth audio system on the chip.

It not only supports full 24-bit audio, but also delivers better digital signal processing than its predecessors. Qualcomm promises to improve signal-to-noise ratio through encoding and decoding and reduce distortion, especially in the 10-20 kHz range.

The need for a dedicated chipset means that you will have to acquire compatible devices to use aptX HD: there are no options for updating the firmware. There are no prospects for any kind of "rescaling" of the audio signal.

But you don't have to worry about backward compatibility: Devices with aptX HD will support all headphones and smartphones with “classic” aptX.

What devices support aptX HD?

The aptX HD codec was announced in January 2016. It will be used in Android smartphones and tablets, as well as in portable media players.

The first smartphone to support aptX HD was the LG G5 released last year. It was followed by his fellows - the G6 and V20.

In addition to them, the aptX HD technology is also supported by high-end smartphones - Vertu Constellation Octane and Luna TG-L900S - which can hardly be called widespread.

Among the portable music player manufacturers, Astell & Kern has become the biggest fan of aptX HD. New codec Supported by its players AK380, AK320, AK300 and AK70, as well as the amplifier / DAC XB10.

In addition, the list of compatible models includes LG Tone Active + and Tone Platinum wireless headsets and Audio Technica wireless headphones: ATH-DSR9BT and ATH-DSR7BT.

Finally, Naim makes aptX HD compatible products: the Naim Uniti Star and Uniti 2 models support this technology.

As the popularity of aptX HD grows rapidly, the list will continue to grow. The complete catalog can always be found at this address.

Based on the materials of the magazine "What Hi-Fi?", June 2017 www.whathifi.ru

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Modern headphone models are not much like their "progenitors". Now it is not just a device that allows you to listen to music from a tape recorder. Thanks to advances in technology, the device has become more mobile by getting rid of wires. The presence of a variety of functions made it possible to obtain a clear, high-quality sound.

Therefore, before purchasing new headphones, you must carefully study their parameters. But if characteristics such as power and sensitivity do not cause questions, then the abbreviation App may cause confusion among inexperienced user... Let's look at one of the important parameters and find out its features.

App support in headphones: what is it

First of all, it should be understood that App is a technology that allows you to receive high quality sound using Bluetooth. To achieve the desired effect, the audio signal is compressed into audio track... Due to this, at certain values frequency and depth, the signal transmission rate reaches impressive indicators. The developer of the function is CSR. The Ap / Aptx features allow you to transmit audio signal with a sampling rate of 24b / 96 kHz.

Reference. There is a conventional wisdom that this technology significantly degrades sound quality. This is actually a myth. After all, the audio file is transmitted not only correctly, but also with high speed... It should also be borne in mind that modern devices are constantly being upgraded. This also has a positive effect on the bitrate of the transferred files.

Experts say that any device will produce higher quality sound if different codecs are not used for this. Therefore, all modern devices equipped with a wireless technology for transmitting a Bluetooth signal can boast the presence of the APP function.

This technology is especially actively used by manufacturers of smartphones and other mobile devices. In addition, many companies are starting to abandon the standard 3.5 connector. Therefore, the App function is rapidly gaining popularity, because the function is supported by most mobile devices of the middle price category.

For example, the American giant Apple has already abandoned the 3.5 connector. All flagship models are equipped with the APP or AptX function.

Trying to keep up with the American brand, many manufacturers have also started to equip smartphones with this technology. However, they did not dare to give up the standard 3.5 connector.

Technology features

The main advantage of the APP technology is its high performance. Unlike codecs, it does not require a lot of power to reproduce an audio signal - this saves the smartphone from excessive load.

To fully appreciate the capabilities of the function, you should familiarize yourself with the following aspects:

1. The main feature of the App function is the ability to compress the audio signal and transmit it at a speed of up to 352 kbps. In flagship devices, the data transfer rate reaches 576 kbps.
2. For data transmission, the technology uses a special method due to which the audio signal is compressed. In this case, high performance is required from the headphones and the signal source.
3. To ensure correct operation, the Аpp / Аptx function must be supported not only by the receiving device, but also by the auxiliary one.
4. Another nuance of the App codec is that it provides an audio signal that is as close as possible in quality to CD. It should be borne in mind that the compression level for them will be different.
5. When using devices with App / Aptx support, keep in mind that the devices take some time to compress and decompress files. This delay is not noticeable on quality products. However, if you plan on watching movies or other videos, be prepared for a slight time lag. Therefore, when buying equipment, you should consider what the device will be used for.

The advantages of the function also include ensuring long-term and uninterrupted operation without periodically recharging the battery.

However, do not forget about the existing disadvantages. The main disadvantage is that the function is supported by a limited number of mobile devices. Despite the fact that the option is ubiquitous, manufacturers are in no hurry to completely abandon the standard 3.5 connector. Usually this technology are used by well-known manufacturers. It should also be borne in mind that smartphones with App / Aptx support are above average.

Modern technology has both advantages and disadvantages. Moreover, their presence affects the final cost of the product. Therefore, before buying, you should rely on the purpose for which the device is purchased and whether this or that function is really necessary.

Bluetooth is the wireless transmission of data between two devices over a short distance. This is done by radio waves (WPAN).

Few know what the name bluetooth technology originated from the name of the Danish king Harald Bluetooth (Harald Bluetooth I, 958 AD). It was he who reunited parts of Norway and Denmark. And the Bluetooth symbol itself denotes the Scandinavian runes B and H.

So, to transfer music via Bluetooth 3 factors are needed:

Sampling frequency(kHz): The higher the sampling rate, the clearer the sound can be transmitted (closer to digital). Distortion in sound is reduced and the audible frequency range is broadened.

Sampling depth(bit): The greater the sampling depth, the higher the resolution of the music. Dynamics increases as the range between soft and loud sounds increases. In this way, it is possible to obtain more subtle sound levels and tonal nuances.

Baud rate(kbps): This is the connection speed at which music sound data is transmitted from the device to the headphones in this case. This, however, is not entirely true. More precisely, this value indicates the possible size of the transmitted amount of data at a certain point in time. The higher the baud rate with the Bluetooth headphone, the more data (at the same time) can be transferred by the device. Thus, the audible sound is greatly improved.

What do the abbreviations aptX, pptx HD and LDAC stand for?

These abbreviations are for Bluetooth codecs and mainly describe various transmission parameters. They differ in sample rate, sample depth, and bit rate. Android 8.0 devices support these audio codecs, and you can enjoy better sound quality.

atpX Is the slowest option for wireless music streaming. This technology provides a maximum bit rate of 352 kilobits per second at a sampling rate of 48 kHz and a sampling depth of 16 bits. The analog signal is read 48,000 times per second and stored with 16 bits. In principle, these are solid numbers. In comparison, a CD is read and stored with identical parameters. However, relatively slow transmission results in almost 50% loss in audio quality. Thus, the sampling depth is only 8 bits, which is related to the resolution of the music.

AtpX HD also has a sampling rate of 48 kHz, but the digital signal is stored with a 24-bit width. The dynamic range is increased, resulting in higher quality sound. The use of LPCM (Linear Pulse Code Modulation) results in lossless data transmission from analog to digital signal. The sound is thus clearer.

PCM is a modulation technique that converts an analog signal to digital. The CD receives the analog sound waves of the music recording.

To what extent the bit rate is adapted in this codec simply for the best sound transmission in headphones is not yet known.

Sony LDAC Bluetooth Codec- the best and fastest of the three wireless audio capabilities.

At data rates less than 1 Mbps at a sampling rate (96 kHz) and a sampling depth of 24 bits, nearly CD quality is achieved.

Compatible bluetooth headphones

The modern market offers both in-ear headphones and regular headphones, for example, Sony h. ear wireless MDREX750BT / B, LG Tone Active + or PSB M4U 8. Full list Headphones that support wireless music listening can be found on the aptX-HD website. Headphones Sony MDR-1000X and MDR-1ABT support LDAC.

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AptX Bluetooth - what is itfor technology? Its essence and method of activation is what we want to acquaint the reader with today. The prefix aptX has been added to the traditional word Bluetooth for a long time, but to this day, few users know what it is. In fact, this is a useful feature that music lovers will especially appreciate. It's just that built-in codec support is difficult to find today even on flagship phones. Often you have to turn it on yourself.

AptX technology:

Today in AptX technologies there are already serious shifts. After the modernization of the codec, the AptX HD version and a lot of other modifications appeared. Read more about technology below.

What is it?

Simply put, AptX is a Bluetooth codec that improves transmission quality sound signal... If the smartphone and headphones with AptX we can hear best sound as 16 bit / 44.1 kHz, and the compression ratio is 4: 1. With this codec, Bluetooth gets the ability to transmit data at a speed of 352 kbps.

In practice, the AptX codec allows a smartphone or other device to stream sound in close to CD quality. The most important difference between "close" CD-quality from the real one is the compression of all transmitted data. This is a characteristic feature of all Bluetooth codecs and is a must to eliminate delays in broadcasting and audio encoding.

Therefore, the aptX adapter compresses the data in preparation for transfer. The receiver (usually headphones) during the playback of the song returns the data to its original state. This inevitably leads to a delay.

To reduce the gap between video and sound, a modification of the technology has been developed - aptX LL, the abbreviation LL stands for "short delay". It is reduced to 32 ms. From a technical point of view, such an indicator is far from ideal, but the person no longer notices the delay. Technology is often present in gaming headsets where minimum latency comes to the fore.

Differences between aptX and aptX HD

There is a modification of the codec with the HD prefix - aptX HD. It has been improved and is capable of issuing best quality audio signal (24 bit / 48 kHz). Works with the same compression level, but with a higher transfer rate of 576 kbps.

In practice, this means thatsupport for AptX technologyimproves sound quality, and aptX HD makes it even better. Lower latency and better quality are the main differences between the HD version and the regular one. The 24-bit / 48 kHz format is a full-fledged HD sound that is appreciated in the circle of music lovers. It is for him that many people buy expensive headphones. It has a minimal amount of background noise and all the details are perfectly audible. The improvement in quality is due to the use of a "softer" compression mode, which distorts the sound less.

How do I know if a device supports the technology?

Today, not all smartphones support aptX. This is a technology developed by Qualcomm, therefore, it is supported exclusively on the hardware and software of this manufacturer. The necessary functionality is possessed by the processor for processing sounds CSR8675 with Bluetooth 5. It can be equipped with Xiaomi, Samsung, iPhone and a number of other smartphones.

How to determine AptX which smartphones support, and which are not:

aptX or apt-X is an audio compression technology owned by Qualcomm to improve the quality of wireless audio transmission over Bluetooth. In this post, we'll tell you everything you need to know about this technology.

Qualcomm aptX logo.

More and more manufacturers of phones, smartphones and other mobile equipment are abandoning the use of a headphone jack in their devices. At the same time, the adapters that can be used to connect standard headphones to such devices are not very convenient and are often lost. Therefore, the ability to listen to music wirelessly is becoming more and more relevant. The only problem is that the sound quality of wireless music can't rival that of a wired connection.

This is where aptX comes in. This technology is designed to improve the quality of wireless sound over Bluetooth and is now gaining more and more popularity. More and more manufacturers of mobile phones, portable players and headphones include this technology in the list of capabilities of their devices.

What is aptX

Astell & Kern MK70 mkII is a player with aptX support.

In fact, aptX (apt-X) is an audio codec that can be used to compress and decompress music when streaming over Bluetooth. It is used as "packaging" in the transmission of audio data, while Bluetooth A2DP (the most commonly used Bluetooth profile) is the courier that delivers the package from the transmitter to the receiver.

This audio codec was developed in the 1980s and began to be used in commercial products in the 1990s. And in 2015, it was acquired by the chipset manufacturer Qualcomm. Since then, aptX has been actively used. major manufacturers in consumer and mobile electronics.

aptX is an update to the standard SBC codec that enables music streaming over Bluetooth A2DP. aptX was designed to reduce the overhead of using SBS. It uses advanced proprietary compression to compress the music down to SBC size while maintaining a larger original frequency range of the sound. Also, the use of aptX allows you to reduce latency, which is especially useful for synchronizing audio and video. But despite significant improvements, using the aptX codec still cannot deliver sound quality comparable to the 16-bit / 44.1 kHz that you hear when listening to a CD.

What is aptX HD

Audio Technica ATH-DSR9BT headphones with aptX HD technology.

In an effort to further improve wireless audio performance, Qualcomm released aptX HD in 2016. According to the company, this version of the audio codec should provide wireless audio transmission. high resolution, up to 24 bit / 48 kHz. But despite the high-profile claims, using aptX HD still leads to losses due to limited bandwidth. However, aptX HD provides higher sound quality than aptX, as well as a dynamic range of at least 120 dB and audio frequencies up to 20 kHz.

In addition, the aptX HD codec provides a lower signal-to-noise ratio, less distortion and requires less processing power, which will have a positive impact on the battery life of your phone, smartphone or portable speaker.

Supports aptX and aptX HD technology

The main disadvantage of apt-X and apt-X HD is the need for support from both the transmitting device and the receiver. In other words, the source device (player, mobile phone or smartphone) and the receiving device (headphones, portable acoustics) must support this technology, otherwise you will not be able to use aptX to encode wireless audio transmission.

This means that fans of Apple technology are out of luck, as the iPhone and iPad do not have aptX support... On the other hand, on Android devices, situations are slightly better and many Android smartphones support aptX and aptX HD. This support is also found on many portable players and wireless headphones. In particular, brands such as Sony, LG, Bowers & Wilkins, Audio Technica and Naim produce devices that support this technology.

Alternative to aptX

Of course, apt-X isn't the only codec that can enhance wireless audio quality. For example, Apple is working on its own technology. They use AAC (Advanced Audio Coding) codec instead of SBC, which gives better results than regular aptX. But, AAC, like aptX, requires headphone support.

Comparison of LDAC and SBC.

Also there is Sony and its LDAC format, which successfully competes with aptX HD. It is capable of transferring approximately three times more data than a standard SBC and can provide wireless transmission music quality up to 24-bit / 96 kHz, higher than aptX HD.

To use the LDAC codec, you will also need compatible hardware... And since this is a Sony development, it is not surprising that most of the devices that support this format are produced by this particular Japanese manufacturer. However, this could change. Beginning with Android Oreo, the LDAC codec became part of operating system Android. Perhaps with more smartphones capable of using LDAC, Sony will receive more requests for licensing this technology from third-party audio manufacturers and we will see more in the near future. wireless headphone and portable speakers with LDAC support.