imm-ersive soundscapes: Listening to imm sound and its new 3D system


I grew up intrigued by sound and sound recording and, having worked for a long time with the BBC, developed a long-term “educated interest” in those topics. Watching movies in ordinary “small-town” cinemas in the ’50s and ’60s, I knew that “cinema sound” was different, and immediately identifiable as such, but it was years later that I learned why, and about the “the Academy Curve” and its phenomenal attenuation of the treble (18dB down at 8kHz) and significant reduction of the bass. Since those days, cinema sound has come forward in leaps and bounds, and the numerous digital audio systems mean that we accept that cinema sound is something very special, and most of us love the audio that accompanies our movies.

Recent months have seen a notable increase in interest in cinema sound developments, with various companies introducing what are becoming known as “immersive” sound systems. I have been fortunate to have the chance to listen to most of these, so when Film Journal International was looking for someone to write about the new imm sound system, I was happy to share my experiences of listening to their completely new audio developments.

imm sound grew out of Spanish company Barcelona Media, a spinoff research company from the local university. The people involved have been creating ideas for immersive cinema for many years, and entrepreneurial members of Barcelona Media decided to develop this work commercially and founded imm sound as a private company to provide its immersive sound system for cinema exhibitors.

I was fortunate to be invited to hear the imm sound system in use in Barcelona, first in a carefully controlled studio environment, and then, more relevantly to FJI readers, in a local multiplex cinema.

Into the studio

I was first taken into a small experimental studio/listening room. Although I was particularly interested in cinema playback, it was good to see that a complete sound production system is in place, and the intention is not to use imm sound just for movies but also to develop it for use with a wide range of alternative content. I learned about the imm sound system through a number of demonstrations. The listening room was equipped with speakers behind the screen, on stands all around the perimeter, and suspended from the ceiling. In conventional terms, the system used 24 channels, but, as became clear later, imm sound has no reference to physical channels, but is a physics-based sound-encoding solution. One single imm 3D soundtrack accepts any number of channels and can cope with any desired location of the loudspeakers in the cinema. This “channel-agnostic” idea was a difficult concept at first.

Hearing is believing
We started with a video clip of close-up shots of a huge lizard moving about in its environment. The three-dimensional audio picked up every nuance as the animal turned around in its grassy woodland habitat. The video then disappeared, and with eyes closed I heard a bat flying all around the room, swooping from ceiling to head level and pushing itself into every corner before flying back overhead. It was extremely realistic and it seemed as though you could actually feel the air moving as its wings flew past. I guess that is as good a definition of realism as you can get from a sound system. Trust me to quibble, though—I noticed that although the bat could swoop upwards, it couldn’t get below ear level, since there aren’t any speakers lower than that height. Maybe something for the future?

From these demos, my main reaction was to note the smoothness with which the sounds moved around the room—it was absolutely seamless, with no sense at all of sounds being switched from speaker to speaker.

The next studio demo allowed me to watch and listen to a cathedral choir. The imm sound recording had captured the essential ambience of the church, with its echoes and reverberations, and the word “immersive” really was appropriate. The imm sound system allows for the audio characteristics of a building to be recorded quite separately from any musical content, so that these characteristics can later be overlaid (think of adding a filter or plug-in to a Photoshop picture) on music recorded with a simple stereo mike. So it is possible to record a choir in a small church or a flat studio and then add the characteristics of a huge cathedral to provide the required overall effect. The possibilities aren’t limited to classical music, of course, and I can foresee tremendous opportunities at pop concerts around the world.

A clip featuring a motorcycle driving through the open countryside had been recorded using a multi-channel microphone. The sound was everything you would expect from the fast-moving vehicle, but for me the most noticeable thing was how clear the ambient bird-song was whenever the motorcycle noise faded. My notes say that the foreground and background sounds were particularly well-separated into different layers or planes—similar to the different visual planes that you can get from a 3D movie.

As one who listens to a lot of live classical music, I was particularly interested in the clip of an orchestral piece. I was told that this had been recorded with only a single multi-channel mike suspended in front of the orchestra, with no extra close-miking of individual instruments. The music was really all-enveloping, which I had come to expect from imm sound, but what I found really surprising was that when the camera zoomed in on the solo violin player, something special happened: Although the sound levels didn’t change, the violin was “brought out” almost as though a close-up mike had been used, and the individual instrument somehow stood out clearly from the background orchestra, without the unwanted effect that close-miking would have brought.

On to the cinema—where imm sound really impresses
The proof of the pudding of any cinema sound system is to hear how it performs in the cinema auditorium. At the Splau Cinema Full HD cinema complex, I was shown how the imm sound processor had been neatly fitted into the sound racks of Screen 9, which was served by a Christie digital-cinema projector. The sound system had been refurbished as part of the upgrade. The installation of a multi-channel sound system in a cinema requires a complete speaker rewiring job, with the installation of the chosen number of surround speakers and up to five ceiling-mounted speakers.

A wide range of content

I sat centrally and fairly high up in the auditorium, and was shown a fascinating series of different 2D movie clips accompanied with imm sound. After the expectedly good imm sound logo animation, I watched an advertisement which rapidly made plain how effective the surround sound effects can be for a range of sports. This left me thinking how good it would be to watch my regular TV football matches whilst fully immersed, the “being involved” effect rendered more powerful than actually being in the stadium.

Then followed a sort of mini-horror movie, The Library, which used sound effects to realistically convey the terrors of being locked up alone in a dark, echoing library overnight. imm sound made full use of the reverberation effects possibilities to simulate echoing corridors and banging doors, with each small noise appearing magnified so as to increase the sense of terror. I can’t wait for the Hitchcock movies to be reissued with imm sound!

The clips had obviously been carefully chosen, and fast-moving scenes of airplane battles, a girl fending off a dragon, and a SWAT team fighting robots provided good examples of what the system is capable of. I was probably most interested to see the teaser trailer for the first full-length Hollywood movie to be made with imm sound. The Impossible, due for release late in 2012, presents a terrifying story based on one family’s experiences of the 2004 tsunami which hit Thailand and the coastal regions of Southeast Asia. The teaser showed some fantastic shots of the water overwhelming everything and the resulting chaos—reminiscent of the terrifying shots of the sea in The Perfect Storm—and the sound effects from the imm process really made you feel that you were immersed. I almost expected to feel wet and cold, so realistic were the sound effects. Perhaps imm sound has a future in those 4D expo presentations where the seats shake and you get sprayed with water!

While you would obviously expect the best immersive results from original material specially recorded in imm sound format, it is going to take some time before large numbers of productions are available in that form, so it was very interesting to hear several demonstrations of how standard video and movie soundtracks had been upmixed using the imm sound workstation. A beautiful video showing part of a full operatic performance of La Traviata began in normal stereo, which sounded fine, if perhaps lacking a little “presence” in the cinema auditorium, and it was good to be able to listen carefully to the details of both singers and orchestra. After a few minutes listening in stereo, the performance seemed to me to burst into life and become “live” as the audio changed to imm sound, with 23.1 channels making it feel as though I was at the original performance. There was certainly no need for the labels on the pictures to tell you which sound system you were listening to—even the most “cloth-eared” audience member could tell that something special had happened when the sound changed to imm.

I then watched a recent movie that I knew well while listening to the standard 5.1 surround sound, and was impressed by its high quality, finding the experience very acceptable and with no complaints—certainly the sort of performance that we have become used to getting in high-quality movie theatres. I suppose that I was unconsciously wondering whether any new sound system would make much of an improvement. When the switchover to imm sound was made, there was in fact a significant change—the whole ambience immediately became more “immersive.” My notes say that it really felt as though I was in the jungle, with animal and bird sounds providing detailed positioning and realistic effects as they moved around. I always tend to be a little skeptical of up-resing processes, whether for video or audio—it is so easy to produce “distorted” results that, although initially pleasing, aren’t anything like the original. Careful comparative listening to both the upmixed performances showed that the imm sound upmixing process had been done in such a way so as not to affect the original sound positioning. The all-important “dialogue” was still positioned exactly where it should be, whereas all the surround effects had become far more enveloping, providing a far more immersive effect.

I enjoyed the various immersive sound effects from the many demo clips. The moving overhead sound effects were smooth-changing and realistic, my only comment being that I would have preferred to have more sound apparently coming from behind me. An examination of the overhead loudspeakers in the very steeply raked auditorium showed that the rearmost ceiling speaker was just about over my head, so sitting further forward in the auditorium would have given me more of the “it’s behind you” feeling.

So where do we go from here? The imm sound system undoubtedly works well, providing a whole new audio experience in the cinema, but with existing surround sound systems already capable of providing great cinema audio and several rival “immersive” sound systems providing competition in this marketplace, how can a cinema exhibitor decide what to do next?

imm sound will be offering demonstrations of their system at the Cinesa Diagonal Mar theatres near the CineEurope conference centre in Barcelona. If you can get there, I recommend that you hear imm sound for yourself—you will enjoy the experience.

This article is adapted from a longer report in the March 2012 edition of Cinema Technology magazine, a U.K.-based journal for cinema professionals. Former BBC broadcasting engineer Jim Slater has been its editor for 14 years.