The New Year’s Concert 2021 in AURO-3D
Despite the second hard lockdown in Austria starting before the Christmas holidays 2020 and lasting until at least January 18, 2021, the traditional New Year’s Concert of the Vienna Philharmonic in the famous “Goldene Saal” of the Musikverein took place as planned, conducted for the 6th time by Italian Maestro Riccardo Muti (see Fig.1). Well, not exactly as planned, of course, as there was no audience allowed. We spoke to Florian Camerer, head of audio post production at ORF TV, about the special situation as well as his ongoing experience with providing an AURO-3D soundtrack for the Bluray release.
Figure1: Riccardo Muti conducting the Vienna Philharmonic at the New Year’s Concert 2021
Q: Florian, we celebrated the 10th anniversary of the AURO-3D format last year. When did you first encounter this immersive sound system?
A: I remember that I was in the lecture hall at the AES convention 2006 in Paris when Wilfried van Baelen introduced the format “Aurophony” together with a few others on stage. Two things struck me in the very beginning: the protagonists thought that there was no word for “3D Audio” yet, and the fact that they had combined the Latin word “aurum” with the Greek word “phonē”. Regarding the first issue, the term “periphony” exists since the early days of Ambisonics, coined by Michael Gerzon in the 1970’s; and I found it a bit odd that with the 100% Greek terms “monophony” and “stereophony” the next evolutionary step would be a mixture of Latin and Greek… But then again, Ambisonics has a similar issue, only the other way round (Greek and Latin)
Q: Well, that sounds like a bumpy start in your relationship with Aurophony…
A: You could say that, yes. But that concerns the nomenclature only. During the same AES convention I listened to the first examples in this format, and that got me interested.
Q: In which way, what were your impressions?
A: I didn’t listen for any flashy effects, although such use is obvious (fly-overs, rain, discrete instruments placed in the height channels etc.). I was much more interested in the subtle things like the portrayal of the room, the feeling of “being there” and especially the timbre, the sound color. The latter was the one attribute that convinced me. I found (and still find) the effect of the height channels on the timbre very positive, it brings the sound of especially acoustic instruments another step closer to our expectations and experiences of a live concert. The longer I listen to AURO-3D, the more I like this aspect of the format, first it is subtle, but after some time you don’t want to switch back to “plain” 2D surround sound.
Q: When was the decision made for the first time to produce the New Year’s Concert in AURO-3D?
A: It was one of those guerilla-decisions basically, I had become friends with Wilfried within a few years after the introduction of the format and thought at one point that the obvious showcase would be this concert. It’s the biggest production of the ORF Culture department, and as I had been doing the surround sound post-production since its inception in 2003 I took a leap and expanded it to AURO-3D in 2014. It was very much down to me asking my colleagues to rig additional height microphones and using those after principal post-production to generate a convincing 3D mix.
Q: Tell us a bit more about the microphone arrangement and the philosophy behind it.
A: It’s probably best to show pictures with all the mic positions (Fig 2+3):
Figure 2: New Year’s Concert 2021 Microphone positions base layer
Figure 3: New Year’s Concert 2021 Microphone positions height layer
We use the Decca Tree as the main mic since the beginning of time and of course, many spot mics, as we have to be able to get more texture when the video guys do these extreme close-ups (which they love!). It is important that the mix is good in 5.0 surround sound and of course in 2.0 stereo. The live mixer (my colleague Martin Gamperl from the OB van sound department) mainly listens to the stereo signal as this is what the majority of consumers hear. The height microphone positions have evolved over the years. In the beginning, I had the front height mics positioned directly over the woodwinds, also because at the first concert I did in AURO-3D there was the Vienna Boys’ Choir singing on the organ balcony which led to this closer placement. When there is no choir (the usual case) the front height mics are now positioned above the Decca Tree. The distance is not great, as vertical decorrelation is by far not so effective as horizontal one (as has been investigated thoroughly be Hyunkook Lee at the university of Huddersfield in the UK). And then there is the practical aspect – we use steel wires to hang most of the mics, and it is not easy at all to have mics hanging down from the ceiling… The back height microphones are roughly halfway between the four mics of the Hamasaki-square. All height microphones are cardioids facing upwards. The height signals really must be additional signals that are not necessary to have a good planar surround mix. Downward compatibility is a big issue.
Q: In which way did the fact that there was no audience in the hall influence the programme and the sound?
A: There was a lot of discussion going on behind the scenes if e.g. there could at least be a choir present that would sit in the audience when not singing. But in the end, nobody except the musicians was allowed in the hall. There was also a strict testing regime in place, with every member of the production team being tested every single day (as well as also the musicians!). Eventually, the programme was executed without any alteration, except for second and third encore, the “Blue Danube Waltz” and the “Radetzky Marsch”. Usually, the audience interrupts the beginning of the “Blue Danube” (the pianissimo tremolo of the violins) with applause, and then the conductor addresses the world with his New Year’s wishes. Not this time. Maestro Muti delivered a compelling speech, in my opinion, stressing the importance of culture and music – and then the tremolo began in total silence, a dream for us in post-production! And when asked about the ubiquitous rhythmic clapping of the audience during the Radetzky Marsch, Muti replied “Well, you will be surprised to learn that it has been composed without audience participation in mind!”. It was intriguing to hear all the nuances of this piece that usually get drowned by the clapping.
Q: Speaking of clapping, there were a few instances where applause could actually be heard, albeit played via loudspeakers and originating from mobile phones…
A: Yes, that was the case. There was a lot of discussion going on in the weeks and months before the concert what could be done to “compensate” the lack of audience. Finally, it was agreed to have applause via smartphones from people all over the world. One could sign up on a special app that was specifically developed by the Austrian company POET Audio, and on the day of the concert, you could applaud at three specific instances, at the end of the first part, of the second part before the encores and at the very end. 7000 people signed up, and the signals were compiled and mixed before being played into the hall via loudspeakers and routed to the OB van for the live mix. What was heard during the transmission was mainly the treated signal mixed in the OB van. As the empty hall has a considerably longer reverb time (about 2,5 sec compared to 1,7 sec with a full hall), the smartphone applause was also mixed with reverb. Despite the rather nice gesture, we were not very happy with the audio quality of the applause, as the signals were necessarily heavily data-reduced…
Q: What are the specific advantages for you of the AURO-3D format and workflow for a production like the New Year’s Concert?
A: I do like the fact that the height speakers are not too high, and that they are positioned above the respective base layer loudspeakers. I think this is a quite natural extension of the 5-channel surround format into three dimensions. Regarding the workflow after the 9-channel master has been finished, I also like that the Auro-Codec works in the PCM domain; you get the robustness of a WAV-File, and if something gets screwed up in the lowest bits, there is still the 5-channel signal available. This is a big bonus in my opinion. During the encoding, I always insist on using the lowest possible level for the height channels in the 5-channel signals in order to minimize the influence of the height channels into the 5-channel PCM master.
Q: What’s the time frame for the release of all the media after the live concert?
A: The first finished master is always the CD version. This is done completely separately, since many years by the company Teldex. These guys start editing the concert right after the last bar of the concert! And on the same day (January 1st) they already do the QC with the conductor. Quite amazing. For the DVD and Bluray, we do video and sound editing at ORF headquarters between January 2nd and 5th, and then we generate several different versions like e.g. for a rerun of the concert at ORF on January 6th, for the production company of the Vienna Philharmonic, for the “House of Music” in Vienna etc. When I have finished the 5-channel files I do the AURO-3D mastering (usually on January 4th in the evening). I always do some EQing of the height channels, like boosting the low end a bit and taking out midrange to get rid of some nasal frequencies. We have one audio post pro studio at ORF which I could modify to be able to listen to the 9-channel signal, so that is the studio I work in. Once the AURO-3D master is ready, I send the files to Galaxy Studios where the guys do the AURO encoding as well as the dts HD Master Audio file which can be directly used by the Bluray authoring house.
Q: You always speak of 9.0 and 5.0, don’t you use the LFE channel?
A: Fortunately, there never has been a volcano eruption during the New Year’s Concert, so there is no need whatsoever to use the additional headroom of the LFE…