Why you should (and shouldn’t) care about it

With the introduction of Qualcomm aptX Lossless technology, Bluetooth headset customers will eventually choose to listen to lossless quality audio together with their wired audiophiles. As always, commitment is the voice of excellence. But whether this will really change your listening habits in the future depends on who you ask.

On the one hand, the existing wireless products are some of the best-sounding headphones on the market. They have powerful noise reduction, virtual assistants, and customization options, which are rare in the wired field. In addition, there are already reliable Bluetooth codecs on the market, including LDAC and aptX HD. However, audio purists will tell you that there is no substitute for the sound quality of lossless audio. Since the development of MP3, this has been a fierce debate, but who should you believe, is lossless Bluetooth audio really that important?

You can also take a look: Bluetooth Codec 101 — Everything you need to know

Let’s start with a quick introduction to lossy audio and lossless audio. Both are digital file compression types designed to reduce the size of music files or streams. Compression is very useful at first, to pack as many tracks as possible into your iPod or MP3 player. Today, it can avoid consuming 4G/5G data limits too quickly during streaming.

As the name implies, lossy compression discards some of the data in the original file to save space, while lossless compression provides you with a completely faithful reproduction that will not be lost when uncompressed, so there is a debate about the difference in audio quality.

Lossless compression is achieved by using encoding techniques designed to optimize the size of audio files without discarding any content. Huffman coding It is a basic example. You can think of lossless music as a bit like .zip or .rar files, but lossless music files are not universal, but use encoding algorithms designed to optimize audio compression. Common physical file types include FLAC and Apple’s ALAC, and aptX Lossless is currently the only Bluetooth codec in this category.

You can also take a look: Explains audio file formats and where to get them

Lossy compression is more complex, and there are a wider range of techniques and models for reducing file size.The common theme is that they are based on the frequency domain Psychoacoustic compressionAccording to the characteristics of human hearing, the parts of the audio signal that have been shielded or hard to hear are removed. In theory, you shouldn’t hear any difference. However, the more aggressive the compression, the smaller the file size, but the greater the chance that the audience will notice the deleted content. Lossy audio file types include MP3, AAC, and OGG, while lossy Bluetooth codecs cover SBC, LC3, AAC, aptX, aptX HD, LDAC, etc.

Lossless compression always sounds as good as the source, but this does not mean that lossy compression is of poor quality or poor quality.Robust research points out No obvious preference Between lossy compression and lossless sources at a decent bit rate.Research shows similar results CD and high-resolution files Yes-although this does not mean that some audiophiles don’t own the coveted ones”Golden ears. “

Why did Bluetooth use lossy compression instead of lossless compression in the first place? The problem is that the data rate of Bluetooth is too low for lossless Bluetooth audio.

Although Bluetooth’s enhanced data rate (EDR) can reach more than 2Mbps, it is not feasible to maintain this rate for real-time data transmission. In fact, 1Mbps, or usually much lower than 1Mbps, is a more realistic and sustainable maximum transmission rate. This is not enough for a 1.4Mbps CD, let alone a 4.6Mbps Hi-Res audio. This limited speed is due to a combination of radio and object interference, data packet overhead and loss, and generally not optimal antenna placement.

Therefore, Bluetooth audio codecs have historically used lossy compression to achieve lower and more sustainable bit rates. Another way to think about this is at the expense of some audio fidelity, giving priority to playback without skips and losses.

To further complicate the problem, the original low-bit-rate SBC codec was designed for voice compression rather than high-fidelity music. Despite subsequent revisions, third parties have stepped in to fill in the gaps with codecs specifically designed to transmit music via Bluetooth. But the goal of AAC, aptX and the upcoming LC3 codec is still a lower, sustainable bit rate of 300kbps and below. Qualcomm’s aptX HD breaks the limit of high-end sound, but is still limited to 576kbps.

Sony’s LDAC is the first codec to try to solve the quality and scalability issues positively with its 330, 660 and 990kbps quality options. The codec also claims to support Hi-Res and promises “same quality as CD” playback (note that it is not perfect playback).After testing, we found that the 990kbps mode is indeed Almost transparent Used for CD quality audio. However, there are still some small elements of lossy encoding, and more importantly, it is difficult for some devices to provide a trouble-free playback experience at this bit rate. LDAC can achieve near-lossless CD playback, but you will often find that the quality is restored to 660kbps, although we think this is still good enough for everyone except the most discerning listeners.

aptX Adaptive is Qualcomm’s alternative method to solve the connection loss problem. The codec dynamically adjusts its bit rate according to the radio environment, reducing the quality of crowded areas to avoid malfunctions. Before aptX Lossless, aptX Adaptive’s goal was still a more conservative 420kbps, but it will now be extended to more than 1Mbps to obtain lossless CD quality audio. Qualcomm’s aptX Lossless is the first codec that claims to be completely lossless Bluetooth audio, bit-accurate playback of CD quality files, and seems to have hardware settings that support this high data rate. Currently, for all Bluetooth codecs currently on the market, the lossless Hi-Res (24-bit, 96kHz) audio track is still out of reach.

Quick reference bit rate:

Qualcomm’s lossless Bluetooth audio technology is a two-pronged attack on this problem. First of all, aptX Lossless supports compressed CD audio data (16 bits, 44.1kHz) without any quality loss, while Snapdragon Sound ensures that both the playback and receiving devices provide a strong enough Bluetooth connection to maintain the necessary data rate without Packet loss.

Qualcomm’s Snapdragon Sound includes Bluetooth radio components, Wi-Fi and Bluetooth coexistence management, and optimized software stack to ensure a stable connection with minimal overhead. Qualcomm pointed out that without these optimizations, it would be impossible to maintain aptX lossless quality audio.

In addition, aptX Lossless belongs to the aptX Adaptive tool suite, which means that the device will also benefit from Qualcomm’s other codec features. For example, if you walk in an area with severe radio interference, the audio bit rate will drop directly from lossless to 140kbps without interruption, so there will be no malfunction or loss. aptX Adaptive also supports 24-bit 96kHz playback, albeit with lossy compression, and a dynamic low-latency mode suitable for gamers and voice calls.

However, there are some caveats. First, existing aptX Adaptive products will not automatically receive lossless support—at least not without firmware updates. You also need to use Snapdragon Sound certified devices on the transceiver and receiver sides to benefit from lossless audio. Therefore, it will take some time for the equipment to penetrate the market with a huge product portfolio. Unfortunately, not all Snapdragon Sound devices necessarily support aptX Lossless, so knowing exactly what you get may not be as clear as it should be.

Until recently, the popularity of compressed heavy music streaming services made lossless Bluetooth audio an unnecessary luxury, which few people might think of anyway. If your source is already compressed, then a lossless wireless connection to the headset is redundant.

However, the service market for music streaming and downloading in lossless CD and high-resolution quality is growing. Apple Music, Amazon Music, Tidal and others provide high resolution and/or lossless tracks for streaming and downloading. It is these customers, and those with their own lossless audio collections, that will benefit from aptX Lossless support when listening via Bluetooth.

After all, it makes no sense to pay a premium for Apple Music’s lossless ALAC files just to downgrade them to lossy AAC when listening through AirPods Pro. However, customers with lossy music collections or those still streaming from more affordable providers may not feel any benefit of lossless Bluetooth audio compared to existing high-quality lossy Bluetooth codecs.

You can also take a look: Spotify HiFi — Everything you need to know

With lossless CD quality, radio-aware scaling, low-latency gaming and voice, and high-resolution support, aptX Lossless seems to be the most powerful Bluetooth audio option in the industry. However, there are still some debates about whether Qualcomm’s standards provide perceptible audio quality improvements and which Bluetooth audio codec is the best choice for consumers with high-resolution libraries. Coupled with whether the proprietary nature of Qualcomm’s technology will limit consumer adoption, rather than more general support for SBC and the upcoming LC3 codec.

Ultimately, the best Bluetooth codec is the one that your headset and smartphone or music player support. Compared with existing standards, aptX Lossless has some quite demanding requirements in terms of hardware. We are waiting to see if the headset manufacturer thinks this is the right technology to invest in, or if the wireless audio quality is sufficient to satisfy their customers. what do you think?

The prospect of lossless audio via Bluetooth will ultimately enable customers to take full advantage of the premium streaming options available everywhere on the market, making Qualcomm a leader in Bluetooth audio quality—though those who prefer high-resolution music collections will probably insist Use wired headphones for longer.

Even so, Bluetooth lossless CD quality audio is good news for audiophiles, who can now enjoy the additional benefit of revisiting the old arguments about lossy and lossless compression and the advantages of CD and high-resolution music quality and auditory perception. Thanks, Qualcomm.