LDAC, aptx HD, AAC, SBC which is the best Bluetooth codec

In recent years, wireless audio is becoming the world’s new trend due to the convenience it brings. The trend of removing the standard 3.5mm audio jack on smartphone models contributes significantly to the development of this technology. With the latest Bluetooth versions now, the connectivity of wireless audio products is very stable, increasingly approaching wired headset models, so manufacturers are now has been and is paying more attention to the quality of the transmitted sound. Wireless audio products must have special codecs to compress audio files for wireless transmission from the source to the audio device, then perform the decompression process at the device suffer that.

Each codec will have different compression capabilities and different data transfer rates, from which the output sound quality will also be different.

SBC

This codec was created by Bluetooth Special Interest Group (SIG), the organization responsible for developing patented Bluetooth technology for A2DP (Advanced Audio Distribution Profile). A profile that any Bluetooth headset must use to connect to a wireless source, so this is a must-have codec. Even if it supports other high-end & more expensive codecs, your wireless audio device must also support SBC to work.

That was the first codec that came out, so it certainly won’t be the best. SBC is only capable of transferring music with a maximum bitrate of 328 kbps.

AAC

That is a joint product of AT&T Bell Laboratories, Fraunhofer Institute, Dolby Laboratories, Sony Corporation & Nokia. This technology was publicly announced internationally by the Moving Pictures Experts Group (MPEG) in April 1997. In addition to being a Bluetooth audio codec, AAC is also considered the standard audio format on YouTube, products from Apple such as iPhone, iPod, iPad, iTunes, Sony Playstation 3,…

AAC also only has a maximum transfer rate with a bitrate of 250kbps, suitable for transferring medium-sized .mp3 files or transmitting the audio of online videos on YouTube, audio in games on devices such as Sony Playstation,…

aptX & aptX HD

Few people know that the aptX standard has been around since the 80s of the last century, often used by film studios or radio stations in the early days of its release. This codec was later acquired by Cambridge Silicon Radio (CSR), eventually acquired by Qualcomm in August 2015. AptX has been popularized with Bluetooth wireless connectivity & appears on many popular technology devices such as computers, smartphones, etc.

aptX is claimed to transfer music at CD quality (up to 16-bit/44.1kHz compress music with a compression ratio of 4:1 and a bitrate of 352kbps.

Meanwhile, aptX HD technology developed by Qualcomm is an upgraded version of aptX. This technology was born to meet the recent demand for high-quality wireless music, supporting maximum sound quality up to 24-bit/192kHz. The compression ratio is still similar to aptX at 4:1, but the bitrate raised to 576kbps. According to Qualcomm’s statement, aptX HD will provide a “better than CD” audio experience.

High-end audio technology is usually only equipped on headsets, music players, professional sound systems, and some high-end smartphone models.

Of course, to take advantage of this technology, both the source (smartphone, music player) & audio source (headphones, speakers) must be supported.

LDAC

That is a high-end wireless transmission technology invented by Japan’s leading electronics corporation, Sony. The LDAC standard operates on three different levels: 330kbps, 660kbps, and 990kbps. It can be seen that, with a maximum transmission bitrate of up to 990kbps, LDAC is far superior to other codecs & rivals aptX HD. According to Sony’s statement, LDAC can also transmit Hi-Res Audio standard 24bit/96kHz with a bitrate of approximately 4.5Mbps by a special transmission method without losing quality.

“The LDAC codec will have about three times more efficient data compression than SBC and aptX, thereby increasing the transmission speed. However, LDAC is still just a Bluetooth codec, so it is still a compressed data transmission type.” That is Sony’s answer to the data transfer capabilities of LDAC. With a special compression method, LDAC can compress & transmit 24-bit/96kHz audio over a bitrate transmission rate of 990kbps. Indeed, with what LDAC can do, this technology has put Sony at the forefront of the wireless audio race.

That is a proprietary technology of Sony, so its popularity is not like aptX HD. This technology is often present on high-end Sony audio products, relatively rare on some high-end audio products from other brands such as Shanling M0, Shanling M5s, Earstudio ES100, and one high-end smartphone model.

Similar to aptX & aptX HD, to take advantage of this LDAC technology, both the source and the audio receiver must support it.

Summary:

With great advancements in transmission technology to meet the growing demand for wireless music in recent times, LDAC & aptX HD have become the standard on mobile devices thanks to their ability to deliver quality sound akin to wired audio transmission. This race certainly had not stopped when other big names recently participated, culminating in the “alliance” of HWA founded by Huawei with LHDC technology.