Profiles and codecs of wireless Bluetooth headphones

When choosing best wireless Bluetooth headphones for a phone it is very important to pay attention to the data transmission codecs that they support. I recommend buying only those headphones, on the box which clearly states that they support codecs: aptX, aptX HD, LDAC or AAC. In this case, you should make sure that your phone also supports the same codecs as headphones. Only in case of mutual support of one of the codecs you will get high quality sound when listening to music.

Most often there are phones and headphones with the support of the codec aptX, it is more than enough to listen to music in mp3 format 320 kb / s or any streaming services.

The highest quality of audio transmission is achievable with the use of aptXHD and LDAC codecs.

SBC

Sound processing using SBC methods has much in common with all the familiar MP3 compression, but the priorities are somewhat different: the main task is not so much to minimize audio losses as to simplify calculations. Everything should be fast, simple and easy to do even for the floppy mobile processor. As a result, SBC does with the sound without unnecessary ceremony – for example, frequencies above 14 kHz are simply cut off during conversion, resulting in a significantly narrower frequency range. Not surprisingly, even with an equal bitrate from MP3 (and SBC allows a bitrate of up to 320 kB / s), audio in SBC-encoding sounds much worse.

bluetooth headphones

LDAC

LDAC is a codec developed by Sony and at the moment it is the most advanced type of best Bluetooth headphones music transfer that can even transmit Hi-Res records. In fact, when using LDAC, you get the sound quality comparable to a wired connection. Of the disadvantages, it can be noted that for today this codec is only available in devices from Sony: phones and headphones.

aptX HD

The main advantage of aptX is its ability to transmit a full-band music signal as close to a CD (16 bit / 44.1 kHz). This is “close”, not true CD-quality, because aptX uses compression, which allows to reduce delays due to encoding and transmission. Classic aptX applies compression 4: 1, and the data transfer rate is 352 kbit / s.

Now go directly to aptX HD. In essence, this is a modernized and improved aptX with the ability to transfer music of higher quality.

His development stimulated the growth of the popularity of Hi-Res-audio; it supports formats up to 24 bit / 48 kHz, the compression ratio remained the same (4: 1), the data transfer rate increased to 576 kbps.

AAC

Due to more complex algorithms, AAC does save more music information than mp3, and even more so SBC. It is not surprising that its inclusion in the set of codecs supported by the A2DP profile significantly improves the sound of Bluetooth-speakers and headphones. The main thing is to make sure that the AAC codec is supported by both “blue-tooth” devices: both that serves as an audio signal transmitter, that works at his reception. If from a pair of such devices the AAC encoding can understand only one thing: the A2DP profile automatically rolls back to the base codec. With quite obvious consequences for sound.

Bluetooth protocol work profiles

It is worth turning to the support of the following profiles:

  • A2DP (Advanced Audio Distribution Profile) – transmission of two-channel audio from the source to the device that reproduces the signal. Can use different codecs to compress the audio stream. It is this profile that is used to transfer music.
  • AVRCP (Audio / Video Remote Control Profile) – allows you to control the standard functions of TVs, home theater systems, etc. The device with support for the profile AVRCP is able to perform the functions of the wireless remote control. Can be used in conjunction with A2DP or VDPT profiles.
  • GAVDP (General Audio / Video Distribution Profile) is a basic profile that provides audio transmission for A2DP and VDP.
  • HFP (Hands-Free Profile) – used to connect the headset and phone, transmits only mono-sound.
  • HSP (Headset Profile) – allows you to connect the best Bluetooth headphones to the phone. You can dial, answer, end a call and adjust the volume.