In an ideal world, we’d all be using wireless products that sound just as good as their wired counterparts. But we also need to be realistic. Convenience is now king, which is why you can’t walk down the street or partake in a Zoom meeting without a pair of wireless earbuds or Bluetooth over-ear headphones catching your eye.
But that doesn’t mean quality has to be completely jettisoned to achieve said convenience. There are still ways and means, which come in the shape of codecs that claim to be able to deliver high-quality audio through a wireless connection.
One of the first examples of this tech to hit the market was Sony’s LDAC codec, which launched way back at CES 2015. But what exactly is LDAC? How does it work and which products support it? Allow us to explain.
What is LDAC?
LDAC stands for… well, we don’t actually know what it stands for. Sony becomes especially shy when it comes to explaining the acronym, so in this instance, your guess is as good as ours.
What we do know is LDAC is a codec that allows you to stream high-resolution audio up to 32-bit/96kHz over Bluetooth at up to 990kbps. According to Sony, LDAC allows approximately three times more data to be streamed over Bluetooth due to the use of more efficient coding and “optimised packetization” of the data.
By comparison, the SBC codec (standard Bluetooth) only achieves a maximum data rate of 328kbps, while aptX HD by Qualcomm can stream at 576kbps. With Qualcomm's aptX Adaptive codec, the bitrate scales dynamically from 279kbps up to 420kbps. Qualcomm also has a new flagship codec, aptX Lossless, which we'll touch upon shortly.
LDAC was awarded “Hi-Res Audio Wireless” certification by the Japan Audio Society (JAS) in 2019.
What do you need to hear LDAC?
You’ll need a source and compatible headphones, wireless speaker or soundbar that support LDAC. It won’t come as a surprise that there’s a lot more support for the codec in Sony products. In fact, when LDAC was first announced it was purely limited to Sony kit, but that’s no longer the case.
When it comes to smartphones, LDAC’s source code is part of the Android Open Source Project, and it should be available on any phone sporting an Android Oreo 8.0 operating system and above. Naturally, manufacturers of any of the supporting products, whether it’s a smartphone or wireless speaker, still need approval from Sony to implement it.
Not sure if your Android smartphone supports LDAC? You need to turn on Developer options so you can find out and pick the best one for your needs. To do this you need to follow a couple of steps...
- Go to ‘Settings’ in your Android phone
- Tap on ‘About phone’ (or device)
- Scroll down to ‘Build number’
- Tap seven times until you see a message saying “you are a developer”
- Back to 'Settings' > ‘Developer options’ > ‘Bluetooth Audio Codec’
- Pick the best quality codec compatible with your headphones or wireless speaker
By default, most LDAC-compatible sources have a “Best effort” setting enabled, which controls the bitrate the device uses and allows it to be automatically adjusted depending on your listening environment. It switches between three different bitrates: 330kbps, 660kps and 990kbps. Therefore, if your Bluetooth signal isn’t particularly strong, then you won’t necessarily be listening in the highest quality all of the time.
Alternatively, it’s now possible to engage a “sound quality preferred” mode on your device, although you might be more prone to signal break up if you’re listening in an area where stability could be an issue. Having multiple wireless networks, large buildings and thick walls all in close vicinity could disrupt your audio stream.
Which products support LDAC?
On the smartphone front, Sony handsets like the excellent Xperia 1 II and Xperia 5 II both work as a source, as does a Sony NW-A55L Walkman. The Apple iPhone is a no-go, but as we've already mentioned, if you own an Android smartphone that runs on the Oreo 8.0 operating system or above, you should have access to LDAC support through your handset. Follow the steps mentioned above to double-check and enable it in your phone’s menu system.
Other manufacturers to have launched LDAC-compatible products include Audeze, Fiio (with its M11 Pro portable music player), Technics (and its EAH-A800 over-ear headphones), iFi (with its iFi's Zen One Signature DAC) Oppo, Panasonic and TEAC, but Sony still has the widest range, especially when you add wireless speakers and soundbars (such as the award-winning HT-ST5000) to the mix.
LDAC vs aptX
So how does LDAC stack up against its close codec rival, aptX? As we've already mentioned, LDAC allows you to stream high-resolution audio up to 32-bit/96kHz over Bluetooth at up to 990kbps. AptX HD can stream up to 24-bit/48kHz at 576kbps while aptX Adaptive supports up to 24-bit/96kHz and scales dynamically between 279kbps and 420kbps.
AptX Lossless launched in September 2021 promising lossless CD-quality (16-bit/44.1kHz) audio over Bluetooth at a rate of "beyond 1Mbit/s". In areas hindered by wireless congestion, this will automatically scale down as low as 140kbps. As is the case with LDAC, you still need the right hardware with the relevant chip to take advantage of the codecs. And, the fact that hardware doesn't tend to support both codecs also makes it tricky to compare the two.
If you happen to have your own kit that supports the LDAC codec and you’ve used it, then let us know what you think about the quality in the comments below...