August 20, 2026 | Leave a comment In July, I had the wonderful opportunity to attend CRANE lab‘s Rencontres Acousmatiques 2026, and experience the Volumiphonium 32.2 immersive system as well as the Perun24 from Slovox Design, a spherical beamforming array. As the travel was generously funded by Montana State University in the form of a Faculty Excellence Grant, I am required to provide a summary of the trip (and especially, the budget!). But since their summary is strictly a one-page affair, I’m adding my complete and unabridged text below. CRANE lab «Recontres Acousmatiques 2026» Post Event Report Ben Fuhrman, DMA Assistant Professor of Music Technology Montana State University August 20, 2026 The central theme of the Recontres Acousmatiques event was “re-naturalizing the loudspeaker experience” which in and of itself seems inherently contradictory. Afterall, the loudspeaker is by its nature as a human designed sound-reproduction object not particularly “natural.” Indeed, you can argue that speakers are in fact mediators of sound, shaping the listening experience through subtle filtering of a signal, altering its volume, and controlling the point of diffusion of the signal in space via position of the speaker. But, of course, the human ears don’t perceive sound as a single localized point in space. Historically, there have been a number of approaches (some more successful than others) used to combat this unnatural acoustic arrangement. The development of stereophonic sound gave way to quadrophonic listening, the common commercially available 5.1 and 7.1 surround configurations, octophonic layouts, as well as Ambisonics and Dolby Atmos. Though the latter three are primarily the domain of academia and commercial venues. All of these audio diffusion systems have attempted to allow for a more “immersive” audio experience by moving from a single point in space (mono) to a line (stereo), to various configurations of a two-dimensional plane (quadrophonic, 5.1 and 7.1 surround, octophonic), and to a three-dimensional dome or cube (Ambisonics and Atoms). But all of these diffusion methods rely on the psychoacoustic illusion of the “phantom center” to some extent. That is, they rely on the brain’s tendency to fill in the gap of missing information and create an illusory image of a sound coming from between two speakers (three in Ambisonics or Atmos), assuming the listener is in the “sweet spot” for listening. Furthermore, all of the speakers exist at the periphery of the array. That is, they lack the ability of natural sounds to move towards or away from the listener, existing only at the outer edge of the playback space. So, what is the solution to re-naturalizing the loudspeaker experience? Two possibilities were presented at Rencontres Acousmatiques 2026, the Volumiphonium 32.2 channel array, and the Perun24 “singing watermelon.” The Volumiphonium approach uses a combination of speakers that exist both at the edge and inside of the array, allowing for two interesting possibilities: the movement of sounds towards and away from the listener, and the creation of “volumetric” zones of sound (or sounds) inside the array. The benefit of moving sounds towards and away from the listener is immediately apparent to any composer who has struggled with the limitations of an Ambisonics or Atmos system; specifically, that the sounds exist at the “edge” of the dome. While this is an improvement on previous models of sonic immersion, it still does not solve the problem of sounds originating and existing in three-dimensional space. The Volumiphonium’s use of inter-array speakers overcomes this (albeit limited by the number of speakers) by allowing for the positioning and triangulation of sounds towards or away from the listener. Building on the aspect of triangulation of sounds between speakers, it also allows for a larger “volume” or size of a sound within the array (a problem that Dolby has attempted to solve in their Atmos software plugins, though still limited by the nature of Atmos layouts existing at the periphery of the space). Creating volume zones in the Volumiphonium array is quite impressive, effectively altering the “sweet spot” problem of traditional arrays by creating multiple ideal listening spots, or spots of dedicated focus to different sounds. During concerts, I couldn’t help but move around to experience the results in different areas of the space, as this change in physical location resulted in a change of perception of sonic objects. It’s a very compelling approach to diffusion, that results in a significantly larger degree in realism in terms of the placement of sounds in space. The Perun24 used a different, but equally compelling approach. A spherical array of 24 speakers positioned on a stand in the “sweet spot” for diffusion in the space (not the listener’s ideal listening position). Through beamforming, sounds are projected directionally from the Perun24, and use the actual space of the room and its acoustic profile and the reflections of the beams to create an immersive sonic environment. While this was best demonstrated with pieces that were natively composed for the Perun (Patrick Kizny’s Untitled piece for space), experiments with volumiphonic pieces from Jean-Marc Duschenne and one of my stereo works diffused through different decoding methods revealed an interesting take on the pieces with new details becoming more relevant in Duschenne’s works depending on the decoding method and on the position of the listener. In my own work, the Perun24 functioned as an omnidirectional point of origin for the sound, again, with the experience mediated by the room and the position of the listener in the room. Whether the projection of highly directed beams, or the use of the Perun24 as a diffuse object, it revealed an important truth about how the location shapes the perception of and localization of sound to the listener: the room shapes the experience. While the volumetric zones were more diffuse than in the Volumiphonium in my estimation, the addition of room reflections added a different type of realism to the sonic experience by localizing the sounds to the room itself. This may seem a little tautological, but it’s an important concept that’s self-evident to musicians, but not necessarily to listeners: the space shapes the sonic experience. Both the Volumiphonium and the Perun24 created more natural sounding experiences, answering the theme of the 2026 Rencontres Acousmatiques event in different, but complimentary ways. Indeed, I speculated during the event that a hybrid approach that uses both systems (Perun24 in the center of a volumiphonic array) would be extremely interesting to build and experiment with as a composer and listener. But of course, this exposes the limitations of the system: the cost and space required. My hope is that as technology improves, speaker prices will decrease, allowing for a mitigation of the first limit, but the physical space requirement remains, and will be the larger (pun intended) issue to the adoption of either system by a wider group. Roundtable discussions continued the theme of the event, by posing the following questions. Introducing a sound or a sound material into an established sound space alters the relationship between all its dimensions and volumes, even if no change is apparent. Thus, its “stability” can break down into multiplicities. Should we, then, create a sound space in which listeners immerse themselves, or a sound space that is spatialised by them ? Given the current diversity of multichannel diffusion devices, should one compose an acousmatic work for a specific spatial configuration, or rather create potential listening spaces for that work ? Can the heterogeneous acousmatic artifact be equated with a given moment in the « espace monde », or is it merely one of its factors ? While the last one was a bit of a joke on the part of host Jean Voguet (the theme of the third round table was really “does anyone have any questions?” and led to a discussion on the history of acousmatic music), the other two were more directly pertinent to the event. I will only provide my own perspectives to these questions as I do not feel comfortable speaking for the other composers, and there is a possibility that something in my notes has been mis-translated from French. Assuming that the spatialization of sound by the listener is through their positioning of their bodies in the venue, this bears a strong resemblance to Xenakis’ idea of the polytope – a mixture of sound, light, and architecture that combined to create a sensory experience. In his Persepolis, performed in Iran at the ruins of King Darius’ palace, the spectators were specifically encouraged to move around to hear different aspects of the musical work, diffused at different stations playing separate portions of the nearly hour-long work as processions of torch bearers and lasers created a choreographed light performance. Here, the position of the listener directly influences their perception of the work, making them the controlling factor of the perceived spatialization, and thus, the curator of their individual listening experience. Of course, this still presupposes intent on the part of the composer to create separate spaces or zones of focus for the listeners. As noted in the question, the “stability” of a sound will break down depending on the position of the sound in space, which is immediately noticeable to the composer as they move out of the “sweet spot” in a speaker array. This is why in my own work I strive to create a balanced mix of sonic events that doesn’t favor one specific location but uses complimentary parts in multiple locations. Some may be explicitly paired (e.g. 0° and 180° may be in explicit counterpoint), while some may be randomly triggered events that occur in random positions (either mono, stereo, or multichannel events). But it has been my experience as both a composer and teacher working in immersive audio that this balance is something that composers are implicitly aware of and strive to preserve (whether consciously or not), to create a mediated soundscape for the listener, regardless of position. Effectively, I favor an “all of the above” approach. Let the listeners move around the space, altering their perception of the work by their physical position in the speaker array. But the composer should strive to create a balance of sounds and musical parts in the array. A sound may be masked, or lose focus (“stability”) based on the listener’s position, but that should be used to reveal new aspects of a work by allowing the listener to focus on other aspects of the piece, not the “missing” sound. This will always come down to practical, and especially financial concerns for me. As I’m in the earlier stage of my career as a professor, performances (my equivalent of publication) are extremely important. As such, if I can compose a piece that works on an existing, and especially, a common spatial configuration, that will always take precedence owing to the possibility of repeated performances. This is why I primarily work in Ambisonics, which allows me to decode a piece to different standard arrays, such as octophonic, 5.1, or Atmos. This versatility is paramount for me, allowing me to easily create multiple versions of the same piece for different venues, which directly correlates to an increase in performances of a composition. But this ignores the spatial advances available in more specialized listening environments such as the Acousmonium or the Volumiphonium, and dramatically reduces the practicality of composing a new polytope in the model of Xenakis. The best compromise that I can offer is to primarily compose in Ambisonics for the sheer versatility it offers, but to take advantage of the opportunity to create works for specialized listening spaces, and cherish them when they are available. All of this leads to the largest question: how will this experience impact my future work? I see two major avenues for future development that will be influenced by my experiences at Rencontres Acousmatiques and the theme of creating a natural listening experience using loudspeakers: my work as a composer and as a professor. As a composer, this was an invaluable opportunity to hear the works of composers Jean-Marc Duchenne, Marc Favre, Yuko Katori, Patryk Kizny, Cătălin Matei, Isabelle de Mullenheim, Kristaps Pukitis, and Jean Voguet. While I have the opportunity to attend festivals and conferences in the US frequently, it’s rare to have a chance to hear the works of my international colleagues, and to have an opportunity to discuss their approaches to composition and spatialization directly. This is particularly important as volumiphonic diffusion is not common in the US, making this an incredibly rare opportunity to learn this approach from practitioners directly. In a similar manner, getting to work directly with Patryk Kizny on the Perun24 system was equally revelatory in the ways in which a space can shape the sound. While purchasing either a Perun24 or creating my own 32 channel Volumiphonium is financially outside of my abilities, I have started some smaller scale experiments in volumiphonic diffusion at home using my quadrophonic system with an additional two speakers inside of the array. Obviously, this is too small of a system to accurately represent a volumiphonic system, but it’s a starting point. I plan on continuing it using some of the additional speakers from Montana State University’s recent reconfiguration of the immersive studio, placing extra speakers within the Dolby Atmos array and experimenting with Spat Gris to control the volumiphonic diffusion. As I become more adept with this setup, I will be working on creating works that take advantage of this approach, adding depth of sonic field to systems that currently diffuse only on the periphery. My hope is that with some additional grant writing, Montana State can expand our immersive system to include a volumiphonic system for both performance and teaching. As a professor, I plan to use these approaches to spatialization that I experienced at Rencontres Acousmatiques in my courses directly. The obvious class this would benefit is MUST 482: Electronic Composition, which already focuses on composing for immersive systems (both Ambisonics and Atmos), so including a volumiphonic approach will complement the existing course content nicely. And as Ambisonics are already a major part of the course, exploring beamforming in depth (as opposed to the current cursory mention) will also be valuable for student knowledge. And while purchasing a Perun24 or similar system is currently outside of our budget, that and additional speakers for a volumiphonic system are definitely future goals. I see the Perun24 in particular as being an invaluable tool for students in MUST 350: Real-Time Computer Music, as it would allow for performances in venues that lack an immersive system (such as our performances in the School of Engineering atrium). The Perun24 or a smaller scale device would also be wonderful for the students in that class as a “virtual performer” functioning as a more naturally sounding diffusion point for their works for live performers and computer by radiating sound in a far more natural manner than a single speaker. But again, this will require additional grant writing to purchase the equipment. Attending CRANE lab’s Rencontres Acousmatiques was a revelatory experience. Volumiphonic diffusion is simply not a well-known technique in the US, and it was amazing to experience it directly as well as to hear the Perun24 in action. Talking directly with the other composers who are far more experienced with these systems has been stimulating for my own creativity, leading to some early experiments on my own, and plans to incorporate these techniques into my classes. While the approaches are fundamentally different (the additional depth of volumiphonic diffusion versus beamforming), the results were similar: a more natural sounding experience for the listener that outstrips the systems I have access to at present. While I will continue my work in Ambisonic composition and diffusion owing to the practicalities of living and teaching in the US, I will also be continuing to experiment at a smaller scale with volumiphonic and beamforming systems to take advantage of the far more natural sound that they offer. Whether that is sound within the array, or the sound mediated by the room, either is a more natural listening experience than I’ve experienced before.