How to Choose a Bluetooth-device for listening to music

Sound without wires becoming more and more commonplace. How not to get lost in the mass of new products, pay attention to the important features and choose a worthy device for listening to music, we describe in this article.

Any sound begins with the source. Today there are a lot of wireless protocols for the transmission of sound. Some of them are much more interesting than Bluetooth, but has not received proper distribution. Today, almost all Bluetooth equipped smartphones, laptops and tablets, and to equip the device is its support for the presence of USB-exit - it five minutes.

Today, therefore, we restrict ourselves to the sound reproducing devices using "blue tooth" (guide is fine and to select the Bluetooth-speakers). this technology has a long history and a lot of pitfalls, the existence of which is not always aware users.

The presence of Bluetooth-transmitter does not mean that the device can be used as the source for wireless audio. Not everyone will allow Bluetooth to listen to good music without distortion. Not everyone is suitable for listening to files with a high bitrate and lossless-format.

What to look for in order to listen to music without wires - be it a high-quality MP3 or rip vinyl, we describe in this article.

Let's start with the most important: this parameter directly indicates whether it is possible to listen to music using the device.

Version Bluetooth

In modern devices often can be found support for Bluetooth 3.0 or 4.0, in some high-end smartphones and other gadgets - 4.1. It may well be, that the acquired headset supports communications using protocol version 2.1. Adapters are backwards compatible, but when you connect the slowest running of the protocol two.

The difference between the normal user protocol for low due to backward compatibility. Basically what is striking - with each new version devices reduces power consumption, but starting with 3.0 added a second module for high-speed data transmission at 24 Mbit / s.

Version 2.1 + EDR transmits data at a speed of 2.1 Mbit / s. This is sufficient to reproduce the low bit rate audio stream. To play back the AV stream is recommended to use a Bluetooth version 3.0 or later.

Please note that for full use as a device in the player, it is desirable to have Bluetooth version 4.0 and higher and better - with reduced energy consumption.

Identify this adapter can be due to the following categories.

profiles Bluetooth

Profiles - a set of specific functions supported devices. Of all employed in Bluetooth for listening to music interested in the following:

1. Headset Profile (HSP) required for communication headset and smart phone and wireless transmission with mono bitrate of 64 kbit / s.
2. Hands-Free Profile (HFP) and it provides only a mono transmission, but with higher quality.
3. Advanced Audio Distribution Profile (A2DP) needs to transmit dual-channel audio stream.
4. Audio / Video Remote Control Profile (AVRCP) It provides control functions of playback devices (without it is impossible to even change the music volume).

To fully enjoy the music needs it A2DP. It not only transmits the audio stream, but also controls the data compression prior to transmission.

However, even if the transmitting and reproducing device (eg, smart phone and a wireless headset) feature Bluetooth 3.0 or 4.0 and support the work with the necessary protocol, you need to pay attention to the codec that used.

codecs Bluetooth

The most important thing to play music on the A2DP protocol - codec, which compresses the audio stream transmitted to the headset. Just at the moment there are three codec:

1. Subband Coding (SBC) - the codec used by default to create a profile A2DP and developers. Unfortunately, SBC shakes considerably rougherThan MP3. And therefore, not suitable for listening to music.
2. Advanced Audio Coding (AAC) - a more advanced codec using other compression algorithms. Sounds much better than SBC.
3. AptX- this is the right choice! At least because of the possibility to transfer files in MP3 and AAC without additional manipulation and re-encoding. So, without sound degradation. However, you should make a reservation. To play different bit rates, there are several versions of aptX. Each of them is designed for your audio stream.

»
The main features of the last two versions of the codec - the maximum reduction of sound delay and reduce the load on the CPU for encoding. Low Latency version achieves a 32 msec delay between the source of the audio stream and a reproducing device. This will reduce the distortion introduced by the equipment while listening to music.

Thus, a certain codec can be selected when the appropriate preferences. If playback lossless-flow is not expected, and high audio delay is not critical - it is necessary to limit the standard aptX and not to overpay for the support device subsequent versions.

It is worth remembering that the desired profile and the codec must be maintained as a smartphone (or other source of the audio stream), and the headset itself (or a Bluetooth-column). Otherwise A2DP algorithm automatically will begin work with SBC.

C Bluetooth any two devices always work using the lowest version, the easiest codec and protocol. So, to fully enjoy the sound quality will not be possible if one of them does not have the support of the necessary technology.

To listen to music for a long time is required Bluetooth support at least version 3.0 of the codec aptX and A2DP profile. To listen to music with high bitrate codec support is needed aptX Lossless - no other will not work, because the music will be compressed when transferred to the playback device.