Thanks to a recent firmware update, the latest version of Apple’s flagship AirPods Max headphones now boast low-latency and lossless audio support over USB-C. Following the announcement, we spoke to John Danty and Eric Treski from Apple’s Music Apps Product Marketing and AirPods Product Marketing teams for a detailed breakdown of what the new features bring to pro-audio users.
Low-Latency & Lossless Support
Since their introduction in 2020, the AirPods Max have become hugely popular in the consumer market, and it seems that many users soon began putting them to work in the studio, too, although many reported a common obstacle: latency. “We had a lot of feedback from folks who wanted to use their AirPod Max with an iPad and Logic, but were finding it to be far too difficult,” explains John Danty, “They were certainly fine for mixing, but playing instruments, not so much.”
That’s all set to change with the launch of the new update. With the latest firmware installed, all USB-C versions of the AirPods Max now support lossless 24-bit/48kHz playback when connected using the included USB-C cable, as well as benefitting from significantly reduced latency figures that make it possible to monitor a performance in real time. As with any audio device, the exact figures depend on variables such as a DAW’s buffer size and the processing delay that's introduced by plug-ins and virtual instruments, but it’s now comparable to the built-in speakers in a Mac, iPad or iPhone. It is also reported by Logic Pro, and remains consistent — something which isn’t the case with Bluetooth, where latency can vary depending on the capabilities of the devices as well as factors such as operating distance and signal strength.
Even when using the new USB-C audio functionalities, the AirPod Max will maintain its Bluetooth connection to Apple devices, meaning that users don't lose features such as Siri and remote volume control.Another issue that Apple’s teams identified when developing the new features is that the headphones’ Bluetooth connection isn’t used solely for audio streaming: it’s also responsible for providing features such as Siri and remote volume control, as well as taking advantage of the built-in mics and allowing the AirPod Max to be used as a headset. As a result, they’ve implemented a method that allows both to co-exist, so users of Apple devices are able to connect their AirPods Max via USB-C and enjoy the lossless and low-latency audio functionality while the other Bluetooth-dependent features continue to work as normal.
The headline feature of the update may be the AirPod Max’s new-found ability to act as a USB audio device, but it’s actually not the only way for users to take advantage of the low-latency audio capabilities. Apple have also developed a new bi-directional USB-C to 3.5mm TRS adapter, which can be used to connect the AirPod Max to any standard headphone output (or to connect a USB-C-equipped device like an iPhone to a line-level input), meaning it’s possible to use them as standard wired headphones with a wide range of audio devices. Of course, that opens up the possibility of using multiple pairs on a tracking session in the same way you would any other headphones.
Pro-audio users aren’t the only ones to benefit from the update, though. The support for lossless audio at 24-bit/48kHz means that everyone is able to enjoy higher quality playback, and the features aren’t exclusive to Apple’s own devices or Apple Music either — the functionality extends to all USB-C source devices and streaming services that support the appropriate bit and sample rates.
Personalised Spatial Audio
Immersive audio is clearly something that’s important to Apple. There’s a huge range of content on their Apple Music streaming service that’s available in formats such as Dolby Atmos, and Logic Pro now offers a wealth of built-in immersive production and mixing capabilities. “When we introduced Spatial Audio into Logic Pro, our goal was to make these capabilities available in the place where people were creating the music,” states John Danty, “And we believed if we did that, artists could start thinking about this new palette of sound in the same way they were doing with stereo.”
The combination of the new lossless and low-latency audio functionality and Apple’s existing Personalised Spatial Audio technology mark the next step towards that goal. Many artists already think about instrument placement and employ stereo effects during the writing and production processes, even if the final mix is being carried out by another engineer, and that same approach is now possible for immersive mixes. Armed with a pair of AirPods Max and Logic running on an iPad or Mac, users now have all the tools they need to approach formats like Atmos, but without needing the space (or budget) required to accommodate complex multi-speaker monitoring setups.
Those who are familiar with binaural processing will know that the perceived accuracy of such technologies can vary significantly from one user to the next. Binaural rendering processors use HRTF (Head-Related Transfer Function) files to emulate the way that our face and ear shapes affect how we hear sound, and reproducing those interactions accurately are crucial to a system being able to convincingly convey things like the perceived distance and location of sound sources. Many systems rely on generic profiles, and while they seem to be effective for many users, some find that they don’t represent spatial information particularly well.
With the latest firmware installed, the AirPods Max offer an all-in-one solution for creating, mixing and listening to immersive audio content.When Apple originally introduced Spatial Audio in 2020, it too relied on a generic ‘one size fits all’ HRTF. However, it was followed in 2022 by Personalised Spatial Audio, which uses the TrueDepth camera in Apple’s iPhone to create a personalised HRTF file based on the user’s head and ear shape, greatly improving the immersive listening experience. The process is similar to setting up FaceID, and simply involves looking into the camera and turning your head from side to side when prompted. The file that’s generated is truly unique to each user, and is created from scratch using the data gathered by the iPhone’s camera rather than picking the closest match from a library of existing HRTFs. It is also automatically shared across all of the user’s Apple devices via iCloud.
It has allowed the company to improve the overall effectiveness of their Spatial Audio processing, too. “Before we introduced the personalised HRTFs, we didn’t know how well that individual profile would fit everyone, so we had to ‘bring sounds in’ and be a lot more conservative in terms of how we placed them,” says Eric Treski, who noticed a significant improvement with Personalised Spatial Audio despite the original profile working well for him. “Once Personalised Spatial Audio came out, it sounded even better to me,” he continues, “Because once the system knew what my actual geometry was, it was able to be less conservative and ‘open sounds up’ so that they’re even more spatialised.”
The team also pointed out that the Transparency Mode — which blends a signal from the AirPod Max’s built-in mics into the headphones — can be used as a monitoring tool for introducing some ambient sound when tracking. For those who are keen to experiment, they recommend feeding a mic signal through a pre-fade surround bus loaded with an instance of Logic's Space Designer convolution reverb, and then routing it back to their headphones to experience real-time surround reverb!
APIs For Developers
So, the recent developments open up some significant new capabilities for those who use Logic, but will it be possible to take advantage of the new features in third-party applications? Apple say that they have developed APIs for both the Personalised Spatial Audio and head-tracking functions, so other developers are free to implement support in their own applications if they wish.
SOS would like to thank Apple’s Eric Treski (AirPods Product Marketing) and John Danty (Music Apps Product Marketing).
