Marcela Rada on the future of spatial audio productions

Audio engineer Marcela Rada explains what inspired her to pursue a PhD in spatial audio, why she’s honing in on workflows and content creation guidelines for spatial audio productions, common misconceptions about the immersive audio format, and the factors that led her to select Genelec monitors for her home studio.

Rada has experience both in the studio and in the classroom, teaching university level students the skills of becoming professional audio engineers and music producers. She has worked across music genres recording, editing, mixing and mastering audio for independent artists and has taught music production and audio engineering at Algonquin College, Interlochen Centre for the Arts, Berklee College of Music and the University of Lethbridge. 

Rada is passionate about using the latest audio and video technology for the creation of innovative and immersive projects and is constantly expanding her knowledge through academic research.

Your passion and expertise in all things spatial audio led you to start a PhD at the University of Surrey on the subject, which will result in a textbook. What first inspired you to explore this as a PhD subject?

I have been researching spatial audio technology for a few years and it was also the focus of my Master's thesis. The reason I started the PhD is because I was teaching at a university and they asked me to design quite a few classes, and one of them was immersive audio. I started designing the course with the knowledge that I had, but spatial audio applied to music and what we refer to as immersive audio are two different things. 

I knew spatial audio technology. Now, when we're creating immersive experiences, there's just so much changing at the moment. It's always changing, and technology develops constantly. I realised that for me to teach a course that was relevant, I needed to do research. I identified a gap in education and in the music industry, and I wanted to target that through research.

How do you aim for the textbook to be an educational tool that will specifically focus on workflows and content creation guidelines for spatial audio productions so that artists, producers and engineers can make the most of the opportunities created by the growth of spatial audio?

It's new for university programs that focus on audio engineering, so schools are slowly taking steps to integrate this topic into their curriculum. One of those things that we're missing is literature that specifically focuses on immersive music production. 

We have lots and lots of research on spatial audio technology, but because this has been supported by streaming platforms just recently, now, we're using the technology and mixing music in this way: What are we doing? What are the workflows? What works? What doesn't work? How do we make sure that it is translating across devices? What are the record labels doing? What are the streaming platforms doing? 

There's so many things happening and so many questions to be answered, so this is where we need proper educational tools, and this is to not only help students that are going through their degrees at university, but also professionals in the music industry who are now in this position where they need to learn again and train their ear differently.

We need education across the industry and in academia. Another gap is that all this research that we've conducted for decades, it's very useful, but it's being left behind because it's so scientific, so we need to apply all of these concepts to what we're actually doing in real life and what mixing engineers are doing, but also everybody in that music production process. 

So this is from the composer, to the artist, to the musicians, to the producer, to the arranger. So even before it's recorded, there's this whole process that could be inspired by technology if everybody had the knowledge and knew what they needed to know. So that's another gap – bringing all the research and things that we know about spatial audio technology and getting it into the music industry and having professionals apply it to their productions.

Are there any common misconceptions about spatial audio that you come across?

There are lots. Spatial audio is still in the works, just like how we went from mono to stereo – lots of things happened, and lots of crazy things happened, and we were mixing things until we figured out what actually works. 

There was some crazy panning perhaps, and that's just in stereo, so there's so much that can actually happen within a 360 sound field. So of course, it's a trial and error type of situation. Some music that was mixed with Dolby Atmos early on, perhaps wasn't better than the stereo version. So listeners question, ‘Why even have this if the stereo version was better?’ 

I think that's a valid point, but I think everybody needs to remember that it's a learning curve, and we went through it before, and we're going through it still. Music mixed with spatial audio technology is getting so much better and it's sounding great, but of course, there are examples out there that are not much better than the stereo version. 

It is valid to question, but I want people to remember that we're still figuring it out. Another thing is that a lot of older music is now being remixed in Dolby Atmos as record labels started pushing that. I think that if something is not planned to be immersive from the beginning, perhaps it might never actually work that way, because it was designed to be in a different format. 

I want to encourage people to focus on new ideas and use the technology to be inspired to create.

You were recently experiencing what it is like to sit in the middle of a loudspeaker arc where you were taking measurements in order to start mixing with your new HRTF (head-related transfer function), which characterises how an ear receives a sound from a point in space. What does mixing with your own HRTF bring to the process and how does it enhance it?

HRTFs are measured individually and they're unique for a person, because it takes into account our bodies – our head, our ears, external ears, and our shoulders, and all of that is so unique to a person. A HRTF that is measured individually and acoustically in that way is going to be very personalised. I do want to remind people that have seen this that this is not very accessible. 

This is something that I had access to because I am a researcher in academia. The research behind HRTFs is whether having your own is going to make a huge difference in your listening experience for immersive audio. You also have to get your headphones measured in the same way and equalise them for that specific part of the filtering that the HRTF applies to your listening experience. It's a whole process. Do I love it? Of course. Is it completely necessary for everybody? No, it's not. So if you don't have it, that doesn't mean that you can't experience immersive music. 

It just means that if you do have it, you'll have a very personalised experience and it could make a difference, and that difference is very different for everybody. For some people, it could be groundbreaking, and for some people, it could be the same as a standardised HRTF that everybody can access. 

But I think it's really cool and HRTFs are definitely 100% necessary for binaural listening; we do need that filtering to experience a binaural format. But the question is, do we need our own individual HRTF? And that's the question…

How do you find the difference between the Dolby standardised Apple scan to this pro scanned HRTF?

It is different, of course, because you're gonna get a lot more detail when you measure your HRTF acoustically than when you simply use your phone to scan your head. You're gonna get a lot more spatial cues, which will then allow you to localise sound more precisely, and that can help you with the ‘cone of confusion’ and lots of other things that come up when listening to a binaural audience. 

It is so individual that I couldn't tell a person, ‘This is what you're going to experience,’ I can only talk about my experience, and it is highly enhanced, for sure, just because it's that much detail. The more information that you have about the space, the more immersive the sound will be. 

You're going to get a lot more information about how you listen and how you perceive sound, and for that reason it's going to be a lot more enhanced. But again, the question is always: is it absolutely necessary? A lot of people experience it in a very close way, just using a standard HRTF.

Given your interest and research in spatial audio, why did you invest in Genelec 8341A point source studio monitors for your home studio?

I've used Genelecs for a long time – years, actually! Lots of the studios that I was in, or even learning in, had Genelecs. I had the opportunity to go to the factory in Finland because of my research and because they are focusing on creating a workflow for immersive setups. 

Lots of studios that now have a 7.1.4 setup have Genelecs. Genelec is focusing on making that setup easier. They're not only developing their speakers, but other hardware to make the routing easier, especially when you have 12 speakers or more, as that can get pretty complex. They do a lot of research around that, and they're developing other hardware to facilitate that process.

They also have their own HRTF measuring software, which I also got to try, and got my file from there. We had some really amazing conversations about the future, where they see technology changing, and they gave me a whole tour of everything that they're doing, which was very interesting. Imagine being in this factory, for me it was like going to Disney World as a kid! 

I got to see how the speakers are made, the quality control that they have, and how careful they are with every single speaker.  We had conversations about what I do and my setup and someone at Genelec advised me on what would work for me. I went for the 8341As and I'm really happy with them. I'm looking forward to getting this room sounding optimal. They're a really good option.