The introduction of Binaural Rendering into our DAWs gives us an exciting new way to mix and master our tracks.
Here is a brief overview of how to get started with mixing in surround.
We know that 5.1 means 5 surround speakers and 1 sub-woofer and similarly 7.1 denotes 7 surround speakers and 1 sub-woofer. For immersive we have the addition of overhead speakers, so for instance, 5.1.4 is 5 surround speakers, 1 sub-woofer and 4 overhead speakers. There are numerous variations on this via different companies, with some having two surround systems at different levels, to give a sense of sound coming from below.
Channel Based Audio
Previously if an audio mix was intended to be played across different speaker layouts then a different mix would need to be created for each one, either from scratch or using Upmix and Downmix tools. The final mix would be exported as ‘Channels’, i.e. one mixed track per speaker.
Object Based Audio
With Object Based Audio, the tracks in your DAW remain independent. You place them where you would like them to be heard but they are not mixed down. During export as ADM BWF (Audio Definition Model Broadcast Wave Format) files, an additional metadata track is created that gives the position of each audio channel, which can include object movement. All tracks are exported individually and the final mix happens at the point of playback, adapting to the size of the surround system. Dolby Atmos is the most well known immersive format and has now been incorporated into the main DAWs. It supports up to 118 objects and has a 7.1.2 ‘bed’ that can be used as the basis for a mix, giving 128 streams of audio in total. An existing channel based audio mix can be dropped into the 7.1.2 bed and used as-is, or additional objects added to create more movement and detail.
Immersive Audio For The Music Industry
While immersive audio has been used by Cinema, TV and Game composers for some time, it’s the addition of Binaural Rendering that makes this format really exciting for the music industry.
We’re still at the early stages of being able to mix and monitor immersive formats in headphones, so if you want a true immersive mix, you’re better off buying an audio interface and kitting out your studio with matching speakers. However with the introduction of the binaural rendering plug-in by Dolby, we can get a basic immersive mix in our headphones straight from our DAWs and export as a standard .wav, .aif or .mp3. Some DAWs now have this rendering technology built in, for others you’ll need to download the plug-in from the Dolby website.
There are still issues with binaural however – it’s a developing technology and not everyone will be able to hear the full benefits of a binaural mix without personalised settings suited to their own ears and head shape. You can receive a ‘head-related transfer function’ scan (HRTF) but it’s an expensive process and one that is currently being addressed by a number of different developers (possibly by offering switchable binaural settings so that we can select frequencies more attuned to our own personal build).
However, while you may not be able to hear music as the mix engineer fully intended, with only a select few listeners getting the full benefit, you can still get a sense of immersive audio with some tracks working better for you than others. Some digital music stores are strongly encouraging the take-up of this technology and you may get featured more prominently by releasing your tracks as Dolby Atmos mixes.
Our conclusion – there’s a lot of development still happening in the field of binaural but it’s an exciting new technology available to us now and it’s only going to get better over time.
Apple Logic, Avid Pro Tools, Steinberg Nuendo and Ableton Live include the Dolby Renderer plug-in. For other DAWs it can be downloaded and added. Learn more about setting up your DAW at the Dolby website.
A stereo mix switching to a basic binaural mix.
Automating object movement – circling seagulls.
Listen to these podcast interviews with key developers in the industry to learn more about Immersive Audio.