We have been using Bluetooth headphones and speakers for years, but there are still doubts about its operation. Not about the pairing process but about things like why some models experience a sound delay when playing a video or playing games. So it can be interesting to know everything about Bluetooth audio and its codecs .
Bluetooth audio, what you should know
Bluetooth connections are not new, we have been with them for a long time and we are all very used to them. Because in recent years they have gone further due to the popularization of wireless headphones, portable speakers and the disappearance of the Jack connector of many phones. Still, it’s not always clear what is around it and how that affects the user experience.
Currently, version 5.1 is the latest version of the Bluetooth standard. Over time and with the launch of each new version, important improvements have been incorporated. For example, more stability in the connection, less energy consumption or a greater capacity to transmit data are some of the points of the most recent.
Thanks to all that, the possibilities have been increasing and we can do things like listen to audio on two devices simultaneously. For example, two AirPods connected to the same iPhone. But there are still questions as to why not all devices work the same. And we are not referring to the quality of the audio, for that there are other factors that affect more than the software.
Quality aside, what really affects the experience are supported codecs for streaming audio. That is what you should know, and that having both Bluetooth version X connections does not imply the same codec support.
Bluetooth codecs
In software terms, a codec determines how information is transmitted. In the case at hand, these codecs are in charge of dictating how the data will be encoded for wireless transmission.
When a particular bit rate (bitrate) is used , the quality of the audio is conditioned. The lower the bitrate, the easier it will be to transmit the information, but the quality will be worse. If it is the opposite, we will have higher quality but more bandwidth will be needed. Maintaining a good balance is what the different codecs allow.
Low Complexity sub-band (SBC)
The SBC codec , used by the A2DP (Advance Audio Distribution Profile) standard, has a particular function, when it processes an audio signal it divides the different frequencies and encodes them independently. This allows you to more aggressively eliminate frequencies that our ears do not perceive as well as others. Thus it is able to further limit the bandwidth required for data transmission.
The problem is that, although it is true that it is practically the default codec and compatible with all B luetooth devices , it is not the one that offers the highest quality. Mainly this lower quality is due to its significant loss of data.
Qualcomm aptx, aptX LL, aptX HD and aptX Adaptive
AptX codecs in all their variants are currently the most recommended option. These offer the best relationship between quality and efficiency in information management. Compared to SBC, the improvements are important and in the aptX HD version 48kHz / 24 bit LCPM sound can be supported. This would result in a transmission with very little loss of information and therefore quality.
Advanced Audio Coding (AAC)
AAC could be a very good option for everyone if it weren’t for their energy needs. That is, although Apple devices use it a lot, Android devices look for other options because the energy management when they use it is not as good as they would like. Therefore, this is a codec that varies depending on the transmission device and not so much on the receiver, which would be the headphones or speakers.
Sony LDAC
Sony LDAC is Sony’s own codec, an option that due to bitrate offers better performance compared to aptX, AAC or SBC thanks to its greater capacity. The only problem is that a priori it is only compatible with the manufacturer’s products. Although Android 8.0 was supported for many phones, they used it. So, if you have a Sony Bluetooth headphones or speakers and an Android device with said version you will be enjoying that experience.
HWA Alliance LHDC and LLAC codecs
LHDC and LLAC are low latency codecs with a bit rate three times higher than SBC, so the audio quality is superior. Created by Hi-Res Wireless Audio (HWA), this codec is already supported by Android devices with version 10 onwards and is ideal for all those uses where good synchronization between audio and video is important.
LE Audio LC3 codec
LE Audio is a new standard for sound transmission via Bluetooth introduced this year. There are still specifications to be set by the end of the year, but it promises lower power consumption and higher sound quality.
These two details are important for a wide variety of applications you may have. Not only to listen to music, but also to be able to transmit audio to different devices independently or to solutions aimed at people with hearing problems. Using the LC3 codec (Low Complexity Communication Codec) it would have a performance three times higher than SBC.
Samsung Scalable Codec
When Samsung announced its Samsung Galaxy Buds, its Samsung Scalabre Codec was also presented, a development together with AKG aimed at stability in data transfer. Thanks to it and similar to what LC3 is looking for, data management is more efficient and therefore, the user experience is more satisfactory in all possible uses. Of course, as you can imagine, it is something that you will enjoy with brand devices.
What is the best Bluetooth codec
At this point you may ask yourself a couple of questions. The first is what is the best Bluetooth codec. Well, it is not easy, because everything depends on the combination of devices. But based on experience, aptX and aptX HD codecs are now the best option and also the most popular one.
Many manufacturers are committed to its implementation. Compared with SBC the audio delay is less, between 30 ms compared to the 100 ms that the first one can have. This is a noticeable difference and can ruin the gaming or video playback experience.
Therefore, to the second question of why having headphones or speakers that support the latest codecs I still have latency problems, the answer is that for everything to work optimally both devices (transmitter and receiver) must “speak” the same language. If the sending device does not have support for a specific codec, you will not be able to take advantage of the one that the headphones or speakers do include.
A trick to improve the listening experience with your smartphone
If you have no problem making advanced settings with your smartphone, you can improve the listening experience with it easily. To do this, if you use Android terminals, all you have to do is activate the developer settings. This is done in the Settings and in the software options, press several times on the compilation number.
After doing that a new menu is activated with the Developer Settings. Enter the Bluetooth Audio Codec section and select the highest quality compatible with your headphones or speakers.
The next point that you can modify refer to the audio sampling (bitrate or bit rate). If you raise it to the maximum the quality will increase, although you also have to take into account that you will need a higher bandwidth, so the type of earphone or speaker you use will also affect. So do tests.
However, these settings may not be available on all phones as they depend on the hardware implemented. But by trying you lose nothing and the improvement can compensate a lot.
