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AptX Bluetooth - what is it? Features of technology and operation scheme. AptX on a smartphone: enjoying sound via Bluetooth Basic concepts of transmitting audio via bluetooth

In each of my headphone reviews, I write about sound quality and technical specifications that provide it. But not all readers understand what aptx hd headphones are. Some people are simply aware that this magical set of letters promises a good sound, for others it is meaningless gobbledygook. Therefore, I want to talk not about specific model today, but about the type of headphones with the aptx codec. What does it give to the buyer, and does it give it at all?

Aptx support in headphones, what is it?

The aptx codec is used specifically in wireless devices to ensure fast transfer of audio files via Bluetooth with maximum quality preservation. I'll try to explain how it works.

The concept of bitrate is the amount of data that you transmit per unit of time.

This number determines the quality of the music. If the values reach 1411 kbps, then the track will correspond to the quality of the recording on a CD. This is the most complete and detailed sound. But wireless transmission data does not yet provide such a bitrate without additional tools.

Therefore, to maximize the preservation of information when transmitting from the source device to wireless headphones, special technologies are used - codecs. They allow you to compress the sound, reduce the sampling rate, and then restore it again.

Some codecs do this with losses, this technology is called Lossy. Those sounds that will be considered less significant are simply thrown out.

If the codec is capable of providing compression and then restoration to the same sampling frequency, that is, to the original sound quality, then it does its job without loss, and they call it Lossless.

The first method allows you to compress data, for example, with the support of MP3 128, by 13 times, but lossless compression is carried out only twice and no more.

Now let's analyze the information received regarding Aptx hd:

Acceptable bitrates reach 576 kbps, in regular Aptx only 384 kbps.
Multiply this value by 2.
We get 1152 kbit/s and 768 kbit/s.
Compare with the bitrate required for lossless audio - 1411 kbps.
We find that regular aptx is only slightly better than MP3 320 or AAC. But headphones with aptx hd allow you to get almost CD sound with minimal losses.

I would like to note that during compression, those sounds that are truly inaudible to the ear are discarded first, so such a high bitrate can hardly be considered Lossless.

Features of headphones with Aptx support

But there is a small “but” in using aptx hd headphones. If the data source is not equipped with such technology, then there is no effect of good sound, and the codec will only load your devices.

Therefore, it makes sense to purchase aptx hd headphones only if similar technology is available in your smartphone. IN otherwise the codec is useless.

First, you need to find out whether your phone or tablet supports the technology. Such information is indicated in the technical specifications. And if the instructions are lost, then the information can be found on the Internet. And then all that remains is to activate the codec in the developer settings, I think you already know how to do this, and if not, then Google will help you.

Advantages and disadvantages

Is it really necessary in wireless headphones aptx hd is a little clearer, but for clarity, you need to evaluate the pros and cons of the technology.

What's good about using a codec? There is only one plus here - high-quality sound, which depends on how accurately the original information is conveyed. As we have already found out, losses are minimal and will allow you to appreciate almost all the nuances of the composition.

The main disadvantage is that only a limited number of smartphones support aptx hd, which means that not everyone will be able to appreciate the codec, even if it is supported wireless aptx hd headphones.

On the basis of Android 7.0 they use aptx technology, in 8.0 they already use the HD modification.

The codec is also supported in latest models from Apple, as well as Samsung. The use of atpx by gadget manufacturers is paid, they are obliged to give license fee owner of the CSR/Qualcomm technology, so the codec is supported by devices from large manufacturers above the average cost. Also, headphones from the budget category, for example JBL, do not support the codec.

I would like to advise that when buying aptx hd headphones, pay attention not only to support for certain codecs, but also to other important parameters:

The sound quality and bitrate are affected not only by the codec used, but also by the Bluetooth version, preferably at least 4.0, as well as the necessary profiles - A2DP and AVRCP.
Autonomy of wireless headphones is one of the main conditions for comfortable use. It is also important how quickly and conveniently it is possible to recharge the device;
Sensitivity and impedance also affect the sound. An increased value of the first in combination with a low second gives a loud sound with good bass and high frequencies, but there is a risk of unpleasant noise;
Uncomfortable aptx hd headphones cannot be used for more than an hour, resulting in ear pain and bad mood. Therefore, no matter what brand the item is, ease of use is more important;
The purpose is indicated in the technical specifications. Headphones can be sports, universal, travel, waterproof, etc. Their functionality will depend on this.

Separately, I want to say about additional features aptx hd headphones that add convenience:

Multipoint allows you to pair multiple devices via Bluetooth. For example, 2 pairs of headphones to one smartphone or vice versa;
Voice assistant Siri or Google allows you to control the device without any movements. It’s enough to say: “Siri, turn it down” or “Call Ivan Ivanovich”, and the program will do everything;
The range, that is, the distance between the smart and aptx hd headphones for normal operation, is within 10 meters in most devices. But there are record holders who do not lose pairing even at a 30-meter distance;
Active Noise Cancellation completely shuts you off from outside noise soundtrack. With these headphones, even at a construction site or on the subway, you will hear nothing but music;
The sound varies depending on the type of headphones - plugs, earbuds or on-ear.

In fact, the types of wireless devices and the variety of their functionality today are amazing. You can choose headphones based on your desires and cost. But the presence and support of atpx hd headphones determines the sound quality, which is undoubtedly very important.

Best models

From the variety of wireless devices I selected short review 3 best headphones with atpx hd support. Of course, everyone has their favorites, and I'm interested in your opinion. Share in the comments which “ears” impressed you with their characteristics, and most importantly, sound quality.

Audio technica ath sr5bt

Closed on-ear aptx hd headphones with a combined type of data transmission. You can use audio plug or Bluetooth version 4.2. Charging is enough for 38 hours of operation. An impedance of 45 Ohms and a sensitivity of 103 dB/mW provide clear sound with muted bass. Frequency range from 5 to 40000 Hz. Available voice assistant, use as a headset and pairing with other devices. These atpx hd headphones cost about 8,000 rubles.

Excellent build quality;
Compactness;
Availability of a wired connection;
Very large battery capacity;
Stylish appearance.

Not very convenient button control;
No active noise cancellation;
The sound is not loud and bassy enough for many.

These headphones seemed special to me due to their softer sound; you don’t always want low frequencies at the head of the orchestra. Vocals and high frequencies predominate here. They also fit very well on the head and do not fall off, even if you move very actively. And of course, a great battery life.

Sennheiser Momentum Free

In-ear aptx hd headphones connected by a cord, the so-called collar. The connection is wireless only, Bluetooth version 4.2. The battery is designed for 6 hours of use. Charging from a PC via microUSB connector in 1.5 hours. Magnetic clasp will help avoid losing your device. When using atpx and on the source, the headphones can be used to listen to classical music. Individual instrumental shades are worked out in detail. Fans of techno and hip-hop will have to work with the equalizer to add bass. Push-button control on the remote control unit below the earpiece. They don't lag behind when watching videos and are used as a headset. Price wireless device about 8500 rubles.

Good charge in a compact size;
Weight only 40 grams;
Reliable brand;
Detailed, high-quality sound, highlighted vocals;
Possibility of joint pairing, as well as quick reconnection;
Remembers up to 8 devices.

The control panel and Bluetooth module get in the way when moving and pull the headphones;
They do not fit tightly and fly out easily when moving;
Bass is muted;
Weak magnetic clasp.

The sound is truly wonderful. Headphones are especially good for watching videos. But the design let us down, so they are not suitable for an active lifestyle. The on-ear model - Sennheiser Momentum over ear wireless m2, although it costs twice as much, is superior in sound quality and convenience.

Harman/Kardon Soho Wireless

Closed over-ear aptx hd headphones. Sensitivity of 100 dB and impedance of 32 Ohms provide balanced sound across all frequencies. bluetooth version 3.0. Touch control. For some reason the manufacturer does not indicate offline time operation and battery capacity. On personal experience, the charge lasts for about 10-12 hours. The sound quality is excellent, all nuances are fully developed, excellent data transfer, both when listening to recordings and when streaming. Suitable for games and videos. These headphones are not cheap, around 15 thousand rubles.

High-quality sound;
Great design;
Made of leather and metal;
Work via cable is available;
Compact dimensions;
Touch control that can be locked.

They fly off when moving;
The sensor responds with a delay of a couple of seconds;
High price;
The microphone loses a little.

When paired with devices that also support aptx, they produce very decent sound. But the most important thing about these headphones is the design. This is a truly stylish thing that makes you feel a little richer.

conclusions

Aptx hd headphones are the future. Many large manufacturers have introduced it into use as mandatory functionality. It is important that the signal source not only supports the technology, it is sometimes activated only manually. Otherwise, it is impossible to evaluate the sound quality. There is no doubt that the codec actually works. And the HD console provides even greater opportunities.

Interesting observation! There is a Jabra Elit 65t model. The specifications do not indicate support for the atpx or aptx hd codec, but these headphones have excellent sound quality. Either the manufacturer decided not to advertise all the parameters, or uses a different technology for transferring audio files. But this means that the codec is not an absolute guarantee of quality.

Like MP3, AAC is a format compressed files. Both encoding algorithms cut off the highest and lowest frequencies, and also actively use the characteristics of human hearing to remove information about sounds that a person has difficulty distinguishing when listening to music. As a result, AAC files sound worse than CDs, but in general the algorithms compress music efficiently enough that most people won't notice a difference in blind tests.

IN Apple Music all files in AAC 256 kbps format

Like MP3, quality AAC file measured based on its bit rate. Common AAC bitrates include 128 kbps, 192 kbps, and 256 kbps.

Without going into technical details, here are the reasons why AAC sounds better than MP3:

AAC encoding uses samples spanning from 8 to 96 kHz, while mp3 encoding uses samples spanning from 16 to 48 kHz, resulting in richer audio;
Higher efficiency of the algorithm;
Greater accuracy when encoding AAC audio is achieved by using smaller sample sizes (128 or 120 units versus 192 in MP3). A smaller sample size is better because it allows you to more accurately describe the analog sound wave in digital form;
Processed more efficiently audio frequencies above 16 kHz. Let me remind you that in mp3 format these frequencies are simply removed.

Thus, higher sound quality while saving space allowed AAC to win a place in the hearts of Apple engineers. In addition, Apple does not plan to allow Tidal and other Hi-Res services to deploy on its territory. So, in their opinion, there is no need to implement other, higher quality codecs in their devices. Therefore, Cupertino residents chose only AAC for wireless audio transmission in their devices. It also seems to me that Apple, for some reason, does not want to pay Qualcomm for the AptX license. It's unlikely that it's about money.

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

Few people know that the name Bluetooth technology comes from the name of the Danish king Harald Bluetooth I, 958 AD. It was he who reunited parts of Norway and Denmark. And the Bluetooth symbol itself represents the Scandinavian runes B and H.

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

Sampling frequency(kHz): the higher the sampling frequency, the cleaner sound can be transmitted (close to digital). Distortion in sound is reduced and the audible frequency range expands.

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

Data transfer rate(kbps): This is the connection speed at which in this case the music audio data is transferred from the device to the headphones. 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 data transfer rate with Bluetooth headphones, the more data (at the same time) the device can transfer. Thus, the audible sound is significantly improved.

What do the abbreviations aptX, pptx HD and LDAC mean?

These abbreviations are intended to represent Bluetooth codecs and mainly describe various data transfer options. They differ in sampling frequency, sampling depth and transmission speed. Android 8.0 devices support these audio codecs and you can enjoy best quality sound.

atpX- This is the slowest option for wireless music transfer. This technology provides a maximum transfer 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. For comparison, a CD is read and stored with identical parameters. However, relatively slow transmission results in almost a 50% loss in sound quality. Thus, the sampling depth is only 8 bits, which is due to the resolution of the music.

AtpX HD also has a sampling rate of 48 kHz, but the digital signal is stored at 24 bits. Dynamic range increases, resulting in higher sound quality. Using LPCM (Linear Pulse Code Modulation) results in lossless data transfer from analog to digital signal. The sound is thus cleaner.

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

Sony H.EAR in Wireless

To what extent the bit rate is adapted in this codec simply to transmit better sound in headphones is not yet known.

Bluetooth codec Sony LDAC- The best and fastest of the three wireless audio options.

With data rates of less than 1 Mbit/s at a sampling rate (96 kHz) and a sampling depth of 24 bits, near CD quality is achieved.

Compatible Bluetooth Headphones

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.

More and more often you can find mention of AptX technology, which is necessary for high-quality wireless sound, but it still remains not the most widespread and accessible.

What is AptX and AptX HD

These acronyms stand for different Bluetooth codecs that have different data transfer characteristics. Their difference is technical parameters: sampling frequency, sampling depth and bit rate. Devices running Android 8.0 and higher fully support these codecs.

The AptX codec allows you to transfer music wirelessly with parameters similar to those for reading and playing a CD. It provides a sampling rate of 48 kHz and a sampling depth of 16 bits, but maximum speed is only 352 kilobits per second, as a result of which the sound quality deteriorates.

AptX HD also has a sampling rate of 48 kHz, but the signal is stored at 24 bits, resulting in a larger range of audio data and higher quality.

In addition, this codec uses linear pulse code modulation, which ensures uninterrupted data transfer from analog to digital signals.

This means that using the AptX codec improves the quality of wireless sound, and with AptX HD it becomes even better.

The difference between the HD version and the regular version is lower latency and higher quality, and the format itself is highly valued by music lovers because background noise are kept to a minimum, and all details are clearly audible.

How to enable AptX on your smartphone

If the device has Android version 8.0 and higher, you can enable the technology through the developer menu.

To open it, go to settings, select the “About phone” section, find the “Build number” line and quickly click on this line 7 times.

Next, go to the developer menu, find the item “Audio codec for transmission via Bluetooth”. Codecs to choose from: LDAC, apt, aptX, AAC, SBC. Click aptX, then reboot your smartphone. The sound quality of wireless headphones will improve.

Which devices support AptX HD

APTX HD technology was developed by Qualcomm, which is known for processors for mobile devices. These codecs are only supported on hardware manufactured by Qualcomm or with their software.

For all parts of this technology to work, codec support is required on both devices – the smartphone and the headphones. In this case, the sound quality will be as high as possible.

If one of the devices does not support the codec, then the sound will be provided using a standard driver.

Top 5 headphones with AptX

Models released in 2018:

RHA MA650 Wireless are in-ear headphones with a metal body and moisture protection according to the IPX4 standard. The sound is bright, contrasty, low frequencies are raised, and there is also an emphasis on the upper mids;
Beyerdynamic Byron BTA are in-ear headphones with a metal body and a unique charging system. The sound is full and deep, good, smooth and powerful bass delivery, balanced and clean mids;
Sennheiser M2 IEBT MOMENTUM In-Ear Wireless are in-ear headphones with a leather collar that is comfortable to use. Low Frequencies They sound clear and detailed, sometimes rising a little. The upper sounds are presented cleanly, the middle has a rich range;
– full-size headphones with excellent passive noise isolation. Mids sound detailed and clear, bass is clear and powerful;
Denon AH-GC20 are full-size headphones with active noise cancellation. The sound has excellent detail and a deep musical stage.

When purchasing any headphones, you should first ask whether they support the required codec.

Smartphones

Since sound playback is provided by headphones, it is not necessary to look for a special “musical” smartphone, the main thing is that it supports the necessary codecs. Great amount modern devices(except for Apple products, which have their own codecs) supports APTX. The HD version is somewhat less common; it can be found in the flagships of LG, Sony, Huawei, Xiaomi, etc.

At the beginning of 2019, the most popular smartphones with AptX HD support:

Huawei P20 Lite;
Huawei Honor 10;
Xiaomi Redmi Note 7;
Xiaomi;
Huawei Mate 20 Pro;
Huawei;
Huawei Honor 8X;
Sony Xperia Z2;
OnePlus 6;
LG V30.

Other devices with AptX HD

There are also a variety of players and media players that support enhanced wireless audio. A complete list of such devices can be found on the official Qualcomm website.

Installing AptX support manually on a smartphone with Snapdragon (step-by-step instructions)

Smartphone requirements

Since this codec was developed by Qualcomm, it can only be present on equipment from this manufacturer.

AptX support is available in the CSR8675 audio processor with Bluetooth 5. It can be installed on Xiaomi smartphones, Samsung, etc.

It is not necessary to have version 8 of Android to activate the codec; sometimes it is technically present, but the developers did not provide the ability to enable it.

First of all, you need to determine whether your smartphone supports this technology, for which you should take several steps:

Download to computer free program Wireshark (needed to read application logs).
Connect your smartphone to the headphones via Bluetooth and turn off the wireless connection.
Open settings on your phone and go to the developer menu.
Find and enable the “Bluetooth HCI Tracking Log” item.
Make sure Bluetooth operation and headphones, then turn on the music.
Wait a few seconds and turn off tracking.
Connect the phone to the computer and find the file in the memory at file /sdcard/Android/data/btsnoop_hci.log.
This file should be opened using WireShark. You need to find Audio non-A2DP AptX, Audio SBC records - this means that the device supports AptX and SBC codecs. The SetConfiguration - AptX command means that wireless audio transmission is carried out through AptX.

Download the file

If upon checking it turns out that the device supports the AptX codec, but it is not used for audio transmission, then it needs to be activated. You can find it on the Internet special file, which is used to activate the codec.

Installation via installZip

To activate:

Download the aptx.zip file.
Make a backup of all data on your smartphone to prevent its loss in case of some unexpected errors.
Turn off the phone and turn it on in “recovery” mode (press the power button and volume up button simultaneously for about 10 seconds).
Select "Install" or activate "Install Zip".
Find the pre-downloaded file and start the installation procedure.
The phone will then reboot and the file installation will complete.

To check whether the codec is enabled, you can again look at the tracking log via Wireshark, or you can use the CatLog application. You need to connect your headphones, turn on the music and enter the request “aptX”. If everything is done correctly, you will see the line a2dp_encoder_init, where selected codec aptX is indicated.

If you need high-quality wireless sound, then it is important to inquire in advance whether the devices support the necessary codecs. Sometimes they are supported on older models, but in this case, activating AptX requires some effort.

When purchasing headphones, you should first have knowledge of some product characteristics. Thus, in this article we will consider one of the data transfer parameters and learn the main features.

App support in headphones - what is it?

Of course, first you need to understand that the presented technology is an option for truly obtaining high-quality sound via bluetooth. Consequently, to achieve this effect, the sound of the playing recording is compressed directly into the track. With its help, with a certain purity and depth of the sample, the speed is achieved at significant rates.

ATTENTION. There is a myth that quality deteriorates enough. Accordingly, this is not entirely true, since the file is transmitted not only correctly, but also with a high bitrate. Moreover, due to modern manufacturers, every year this or that device is constantly being modernized.

We can say for sure that the sound from this or that unit will be much better in quality than it was reproduced without the codec. Today, due to its effectiveness and some significance, almost every building has this technology, which sends an audio signal directly via a Bluetooth channel.

Peculiarities

In order to determine as accurately as possible this technology, it is advisable to consider the following aspects:

The first thing to remember is that thanks to app, the audio file is significantly compressed, and then, accordingly, transmitted at speeds of up to 352 kbits per second. REFERENCE! If we consider the most modern designs, then in them the parameter can reach up to 576 kbit/sec.
We should also not forget that a special method is used in which the audio stream is compressed. And quite high performance is directly required from the headphones themselves or the audio system.
An important factor in the most correct performance is the support of technology not only at the receiving structure, but also at the auxiliary one. Moreover, because of this, a lot of energy is consumed in the device, so the load falls on it significantly.
A distinctive feature of the codec is also the fact that the sound quality of music or other audio is ensured as close as possible to that of a CD. However, their compression levels are different.
You need to understand that it takes some time for the signal to be reduced before sending, and for the recognition equipment to unpack it directly during playback. But, of course, the user may not be able to replace the delay in operation. But if you are watching a video with sound, then the loss of time will be significant. So, with the acquisition of such support, it is worth thinking about what it will be intended for.

Thus, in each feature it is possible to find both advantages and disadvantages. When choosing, you should rely on the purpose of the purchase. In addition, it is worth paying attention to the updated versions, which are technically, most likely, much better than their predecessors.