Broadcast mix engineer Mark Gittins is rather skeptical of headphone based virtualisation systems based on previous experiences, so what does he think of Virtuoso - the binaural translator from the Applied Psychoacoustics Laboratory? Let’s find out…

What Is Virtuoso?

Virtuoso is a plugin and standalone app that has been developed by The Applied Psychoacoustics Laboratory (APL) at the University of Huddersfield. It has been over five years in the making and is the brainchild of Dr Hyunkook Lee, internationally acclaimed academic, renowned for his expertise in 3D audio.  

So what does it do? Well, it is a binaural translation tool that allows the user to monitor on headphones and hear a binaural representation of both a room and speaker system (in many different layouts, more of that to come).

When the lovely folk at Production Expert asked me to write about it, I’ll be honest, I was reluctant as I’ve been quite vocal about my dislike of other headphone based virtualisation systems in the past. I just think they sound a bit naff. However, I had a bit of a poke around online and found this quote from Mr Bob Katz himself… ‘I thought I was listening to my speakers! Virtuoso fooled me. Amazing recreation, we finally have a translation tool that allows mixing with headphones’… Well if Bob likes it… 

With my new found enthusiasm, I installed the software and went about setting it up on my system at Sensound, my 9.1.4 Atmos mix room. For reasons I won’t go into in this article, I currently send all my rerenders back into Pro Tools via aux I/o. So from here I just sent the 7.1.4 rerender back out of Pro Tools via another aux I/o path and into the Virtuoso standalone app.

Before I delve into the features of the software, I must comment on my first impressions of the binaural virtualisation that I experienced. Never before have I heard such amazing binaural detail from behind and above. I was blown away by how moving an object around my head was translating binaurally on headphones. Something other binaural engines are yet to get right, in my opinion. On a subsequent call with Dr Lee, he explained that this was down to both the quality of the selection of HRTF (Head Related Transfer Function) models on offer, as well as the APL Spatial Audio Engine (ASPEN). This combination of cutting edge technology mitigates some of the issues other binaural engines suffer from, such as front/back confusion, as well as a difficulty to localise elevated sound sources.

Now let’s explore some of the features of the software. 

First of all, speaker layouts. Virtuoso currently supports 53 input configurations of up to 26 channels for all popular loudspeaker formats from mono to 3D, including ITU-R, Dolby Atmos, Auro-3D, MPEG-H, NHK and various regular arrays ideal for Ambisonics (e.g., Quad, Cube, Octagonal, Lebedev grid). That’s a lot!!! I must say, I flicked through and listened to all of them but was mainly interested in the Dolby Atmos layouts as that’s what I use in my room.

Next up, we have virtual room presets. Here we have a selection of seven room simulations; the APL Listening room (APL’s ITU-R BS.1116-compliant reference listening room), three control rooms (Large, Medium and Small) as well as a Dubbing Stage, Home Cinema and a Living Room. These rooms have been scientifically designed using the ASPEN 3D geometric acoustic simulation and have been tuned to sound highly realistic and natural. We also have the ability to customise the chosen room’s acoustics. Here you have the ability to tweak the room dimensions, high and low frequency dampening, reverb liveliness, RT60 time, speaker distance from listener as well as overall ambience level. I found these controls more than sufficient to tonally match the room sound to that of Sensound (very very dead).

The software provides three HRTF models A, B and C as well as the ability to load in a Personal HRTF via the SOFA format. I don’t have a personalised SOFA file so I clicked through the presets and found that ‘B’ worked best for me. It provided the most accurate spatial representation of my room as well as minimum tonal shifts when moving objects around. 

Head Tracking is a thing. Oh isn’t it just. It’s a controversial thing amongst us immersive music mixers. As in, Apple Music AirPod Pro/Max users, please turn it off!! However, in a room virtualisation, it’s pretty useful. OSC (Open Sound Control) and manual sound field rotation are both available. 

We also have both Headphone compensation and Speaker EQ. The Headphone EQ section provides curves for over 65 (and growing) popular headphone brands. This is to make the frequency response of the headphones perceptually flat, providing the most accurate presentation of the HRTF model selected. Also provided are the Speaker EQ filters that model the on-axis frequency responses of 11 popular loudspeaker models. These EQs allow you to choose virtual loudspeakers with different spectral balances for monitoring purposes.

Conclusion

That’s a lot of features, allowing you to really customise the virtual space. I set myself the task of tweaking the plugin and trying to get it as close as possible to my Atmos rig and room, and I must say, I was very impressed. This software has instantly become useful for those times when I’m not at the studio, and need to make a tweak to a project on my laptop, mixing through Virtuoso really does give the impression of mixing through speakers in a room.  

Would I sell my speakers and just mix on headphones now? Absolutely not. I’m a firm believer that immersive mixes need to be experienced on a well calibrated speakers system before being released, to be fair I feel the same about stereo mixes. Personally, I’d hate to just mix on headphones. However, if ever I was to mix in a room I didn’t know, I’d be sure to set up Virtuoso. It’s already proved useful as a mobile ‘b’ rig, allowing me to get a mix started on my laptop in a hotel room, and I’m currently talking to some outside broadcast facility companies that I do some work for about deploying it in Broadcast trucks when the monitoring situation isn’t always ideal. I’ve recommended Virtuoso to a few Atmos mixer friends and many of them seem impressed as I do. I think it’s a useful tool in addition to an Atmos mix rig and am excited to see how it continues to develop.