The Cube: Virgina Tech High Density Speaker Array

In the small town of Blacksburg, Virginia, the Moss Arts Center, at Virginia Tech hosts one of the worlds few high-density loudspeaker arrays called the Cube. With 139 individually addressable audio-channels positioned around a 50’ x 40’ black box theater, this space takes the concept of immersive audio to the next level. Since its initial construction in 2013 the Cube has hosted numerous artists, researchers, and technologists in a variety of contexts including live performance, scientific research, technological design, and more. By being such a unique space it challenges scientists, technologists, and artists to think outside ‘the cube’ to find new ways of researching, developing, and creating content for such an environment.

The technological infrastructure of the Cube was initially envisioned in 2008 by Ivica Ico Bukvic, associate professor of composition and multimedia at Virginia Tech. Its original design was articulated as “a collaborative research environment that would combine visualization, motion tracking, and full-scale immersive 3D audio.” The Cube, now fully constructed, has met all of those initial design goals and continues to push the boundaries on what kinds of things may be capable in that space.

Eric Lyon, composer and professor of music technology and composition at Virginia tech, has been at the forefront of creating compositions for the Cube. He has also developed the Spatial Sound Music Workshop (SMW), which is currently going into its’ fourth year, and Cube Fest, which will be taking place on Aug. 9 - 12. Both programs offer artists from all over the world the opportunity to research, create, and perform works specifically made for the Cube. Cube Fest in particular allows new audiences to come and experience the works composed and presented in the space.

In this highlight we will hear from both Ico and Eric as they discuss the challenges and rewards of working in such a space, their experiences of bringing different artists into the Cube, and their hopes for the future!

What was the initial vision behind the construction of the Cube?

Ico: Ever since I joined Virginia Tech I dreamed of a space like the Cube where I could pursue my passion for the spatial sound and its underutilized potential. My early work at Virginia Tech focused on the 24-loudspeaker (4x6) anterior displays I used to paint geometric shapes and even paintings using solely sound, eventually using it to play a game of aural Pong.

Having been given a unique opportunity to partake in the visioning and, in part, the implementation of the new Moss Arts Center, a $100M cutting-edge and first-of-a-kind facility in Virginia Tech’s history, I wanted a space that supports the broadest array of creative scenarios, while providing the necessary affordances for its easy repurposing. In other words, I was hoping for a space that could be a research lab in the morning and a concert hall, a black box theater, or a communal interactive installation space in the evening. This meant the space was supposed to be more than just an immersive audio environment, offering affordances like projection and motion capture. In terms of audio infrastructure, I envisioned a space that supports as many different approaches to spatialization as conceivably possible, including the wave field synthesis that remains by and large notably underrepresented in the United States. I am pleased and incredibly lucky to have seen this vision become a reality. The Virginia Tech Cube has not only met but also exceeded this vision by becoming an environment that is as close to the Star Trek’s Holodeck as it gets using today’s technology.

For more information on the design and early work in the Cube you can read a paper from the Computer Music Journal on the Genisis of the Cube here.

What challenges and rewards have you faced in exploring artistic practices in such an environment?

Eric: One of the major challenges for the Cube’s media systems design, up to the present, is that there have been very few practical models to rely on, since the Cube is such a unique media facility. When we began employing the Cube’s high-density loudspeaker array (HDLA), most audio software was not fully capable of processing the number of individual channels that we required, with the flexibility that we required. This limitation has considerably improved since 2013, but many audio software packages are still not fully multichannel, meaning that they do not yet support an arbitrary number of audio channels. The trend is clearly for these software limitations to be removed, as public awareness of the capabilities of multichannel audio continues to accelerate.

On the artistic side, we were faced with a multitude of opportunities, since we could explore approaches to multichannel composition and sound art that are only possible at a few facilities around the world. From the outset, we sought a balance between artistic research conducted by Virginia Tech faculty, and by guest artists and researchers from the outside world. To that end, we created both the Spatial Music Workshop, to give artist/researchers considerably hands-on experience with the Cube, and Cube Fest, where we could present a range of immersive audio artworks to the public. We integrate the Cube into public events that we host, such as SEAMUS 2015 and NIME 2018, adding unique artistic opportunities to established conferences, and we support a small number of artistic residencies throughout the year. Faculty members at Virginia Tech are constantly engaged in new artistic and research projects in the Cube.

As a result of all of this activity, the Cube has quickly become one of the most exciting places in the world to experience multichannel music. One of the great rewards is to hear something genuinely new and striking. In my piece 'The Cascades', composed in 2015, I made the sounds of a waterfall spreads out over the ceiling, and then gradually descend on the audience and begin swirling around them. Though simple enough to describe, the sonic experience was so rich and unusual, and would not have been possible to create with lower-order planar surround systems such as 5.1 or octophonic.

It is equally exciting to hear so many new ideas and approaches from the artists and researchers that we invite to work with us in the Cube. It is a great privilege to be at the center of all of this activity, and we embrace our responsibility to engage with local and global communities to maximize the contribution of the Cube to our present and future musical cultures.

You work with a lot of artists/composers, how do you find their work is influenced by the opportunity to work in the Cube?

Eric: When working during the Spatial Music Workshop, artists very quickly discover that the Cube is very different kind of performance space than they are normally accustomed to. Many artists get interested in elevation, and the possibility to put sound into the ceiling. Certain spatial techniques, such as Higher Order Ambisonics, work much better in the Cube’s HDLA, compared with lower-order loudspeaker arrays. Artists come to the Spatial Music Workshop with a plan for their creative work, and almost as a rule, their project concept evolves as they explore the capabilities of the Cube.

What have been some of the more interesting things you’ve seen done in the space since it was built?

Ico: Cube has supported everything from immersive Holodeck-like experiences, to interactive communal installations, to football simulations, and even flying snakes (not kidding). Personally, there are three projects that come to my mind:

  1. The spatial aural tornado simulation which was the first work written for the newfound High Density Loudspeaker Array (HDLA) infrastructure and tests the limits of what may be computational possible by mixing down over 1,100 48KHz 24bit audio streams into 128 physical channels with a sub-10ms latency. This project was demoed countless times, including a live broadcast from the Cube by Jim Cantore and the Weather Channel. The same also served as the foundation for the D4 Max library.

  2. Spatial Audio Data Immersive Experience (SADIE), an NSF-sponsored research project I am currently heading with Space Science colleague Dr. Gregory Earle and where we are studying the role of spatial sound and the newly coined immersive exocentric environment in sonifying complex data. In this case we are focusing on the immersive sonification of atmospheric data. The project has also yielded a glove-like interface that works in conjunction with the Cube’s motion capture system to collect participant performance data while concurrently also serving as a compelling NIME, allowing users to perform spatial music using natural arm, hand, and finger gestures. The end result is a Minority Report-like interface for manipulating spatial sound.

  3. Most recently, an immersive installation developed in collaboration with colleagues Zachary Duer and Meaghan Dee. Forgetfulness is an interactive VR rendition of Denise Duhamel’s poem from the Mobius series exploring actions of an Alzheimer's patient that virtually hovers inside the Cube and is explored using the wearable system consisting of a laptop, Oculus Rift, and Empatica wristband. User’s position is captured through the Cube’s motion capture system and they can freely navigate the entire approx. 40x40ft space in which the poem is displayed. The sounds emanate based on the poem’s words and their location. Some words/phrases are punctuated by self-contained musical experiences that last for minutes. Others are accentuated by a brief earcon-like sound. As multiple concurrent participants navigate the virtual poem they see traces of each other, as well as a colored trail that corresponds to their biofeedback (heart rate and skin sweat monitored by the Empatica wristband), resulting in a memento of those who have previously traversed the virtual space and the places that may have had a strong emotional impact on them (e.g. the poem punchline). The ensuing immersive space looks like a near-realistic version of the Cube itself as if seen through the distorted lenses and whose volume is increasingly populated by a nebula-like cloud of human emotions.

Eric: I’ve recently been quite interested in spatial movement between literally “walls of sound,” where groups of sounds move from one large cluster of speakers to another, rather than just panning between two loudspeakers, as in stereo. I’m also spatially orchestrating chords, so that different notes of a chord exist at different elevation levels. More recently, in collaboration with Ben Knapp, I’ve been using the Qualisys motion capture system to locate sounds in specific places within the Cube, as controlled by the location or movement of a performer being tracked by the system.

My colleague Charles Nichols created a very effective installation recently called Shakespeare’s Garden in which Charles’s ambient music and environmental sounds were put into the Cube’s HDLA, while recordings of texts from Shakespeare, performed by theatre students at Virginia Tech, were put into our Holosonic audio spotlight speakers, so that each text could only be heard at a specific location in the Cube, where covered by a particular audio beam. The combination of the Cube’s main HDLA and the Holosonic speakers is very promising indeed.

There have been endless wonderful experiences from our composers and performers at Cube Fest. Last year at Cube Fest, the Random Ninjaz in collaboration with Electroskip gave a powerful hip-hop performance in which specially designed sneakers were used to control spatialization from foot movement by individual dancers within the group. And I’ll never forget the effect that you created in your Spatial Music Workshop piece, Monica, where you put the sounds of footsteps onto the ceiling of the Cube!

Do you find audience members have unexpected reactions to experiencing performances in the space?

Ico: There are as many different responses as there are individuals. Some are profoundly changed by the experience, others barely notice it. The tide is shifting, however, and with each performance we get more audience members who are increasingly sensitive to the structural manipulations in the spatial dimension.

Eric: Having spent a great deal of time developing and performing music in the Cube, I’m rarely surprised by audience reactions, since I have already had most of those reactions myself. I find audience members’ reactions most gratifying when they both perceive something special about the sound in the Cube, and connect spatial aspects of the sound to their own powerful aesthetic experiences. This is very meaningful to me because so many of our audience members at Cube Fest are not specialist listeners (composers, producers, engineers, etc.) but rather music lovers from the general public. Such audience members have found the experience of listening to electronic music in the Cube overwhelming, immersive, and intriguing. Special awareness of motion and distance are often mentioned. When audiences hear familiar program materials (each year at Cube Fest, we present a spatialized classic rock record), audience members often report hearing details in the music that they had never noticed before.

Cube Fest is coming up. Can you talk a little about what that is and what kinds of things people might see there this year?

Eric: Cube Fest is an idea I brought with me, when I joined Virginia Tech in 2013. We were always planning to build out an HDLA in the Cube, and it seemed to me that it was worth producing an electronic music festival featuring music created expressly for presentation on HDLAs. There are still very relatively few HDLA facilities in the world, and even fewer music festivals focused on spatial music. (BEAST FEaST in Birmingham, UK is one of them.) The spatial music festivals I was aware of predominantly programed music that was originally composed for lower order spatial configurations, such as octophonic, 5.1, or even just stereo, which was then performed (or “diffused”) on the higher-order HDLA. Cube Fest was based on a more ambitious concept by stipulating that all the music should be originally composed for HDLA format. That also meant that we had no idea when we started, if we would receive enough music submissions to fill the festival. As it turned out, even at our first Cube Fest in 2016, the response was international in scope, and we received more excellent HDLA music than we could fit into the three days of the festival. And the number of HDLA submissions to Cube Fest has grown every year since we started.

A second, crucial concept of Cube Fest was provided by Ben Knapp, the director of the Institute for Creativity, Arts, and Technology (ICAT). Ben challenged me to program not just music from the experimental tradition (where my own creative practice is situated), but from a variety of different popular musical genres as well. We somehow managed to achieve this desideratum, which immediately distinguished Cube Fest from many other academic music conferences, such as the International Computer Music Conference (ICMC), where almost all of the music is based on some experimental practice or research agenda. The stylistic variety at Cube Fest allowed us to explore spatial musical experience across genres, and also made the festival suitable for presentation to a general audience. (In contrast, for academic events like the ICMC, the audience is essentially the participants of the conference.)

For Cube Fest 2018, we were inspired by the evolution of the popular, beat-oriented audio software Ableton Live from a stereo output format to a multichannel output format. To celebrate this important development, we invited a community workshop on Live 10 from Ben Casey. We have also programmed two artists with a focus on beat-oriented music: Christopher Willits (who is also involved in developing spatialization software for Ableton Live), and Dustin Wong & Takako Minekawa. We are also tremendously excited to present a collaboration between Anna & Elizabeth, expert performers of Appalachian folk music, along with Linda Buckley, a modern Irish composer and vocalist, working with ICAT staff to create a unique performance designed just for the Cube. I encourage readers to explore the Cube Fest website for further details.

The actual development of Cube Fest is a creative collaboration among members of the planning committee. Although I have always served as artistic director, programmatic ideas have increasingly come from other committee members, including Cube Fest technical director Tanner Upthegrove. The first two Cube Fests were organized by program director Willie Caldwell, who brought incredible energy, ideas, and organizational panache to the endeavor. This year we have a new program director, Donnie Bayles, who has brought his own new ideas and style to the organizational process. This year, directorship of Cube Fest has passed from Ben Knapp to Ruth Waalkes, who is also Executive Director of the Moss Arts Center, and Associate Provost for the Arts. Ruth is a highly accomplished and progressive curator who has empowered us to pursue increasingly ambitious artistic initiatives at Cube Fest 2018. Our collaborative approach seems essential to the success of Cube Fest, which is fitting since building community has always been an express purpose of Cube Fest.

You also host a Spatial Music Workshop for artists, technologists, and researchers. The workshop allows the participants to learn, experiment, and create in the space. What kind of influence has this had on the development of creative practices in the Cube?

Eric: Each participant of the Spatial Music Workshop (SMW) brings his or her own creative agenda, and then they develop, experiment, refine, and share their ideas with the other participants, and finally share their work-in-progress with a Cube Fest audience. So the work of the SMW participants really becomes part of the creative practices in the Cube. And we have several guests, such as Shawn Greenlee, Kerry Hagan, and Elizabeth Hoffman, who have repeatedly participated in Cube-based events, such as the SMW, Cube Fest, and one-off events with significant Cube involvement such as SEAMUS 2015 and NIME 2018. We refer to our recurrent guests as “Friends of the Cube.”

What other kinds of opportunities are available for artists and audience members to engage with the Cube?

Ico: We have residencies, open houses, performances, and special events, including Digital Interactive Sound & Intermedia Studio (DISIS) events that take place once a semester. We regularly interface with the space both on research (e.g. National Science Foundation-funded SADIE project I am currently running) and arts sides of the spectrum, including ensembles, such as the Linux Laptop Orchestra (L2Ork). The cumulative effect we are going for is heightening the awareness of the spatialization as a means of musical expression (spatialization as a NIME) to the point of its emancipation as an equal to the well-established dimensions of sound that drive today’s musical expression, such as pitch, rhythm, and more recently timbre.

What do you hope to see happen in the Cube in the future?

Ico: Further growth and constant and consistent re-envisioning of what Cube is, what is its purpose, and how we can leverage the newfound infrastructure to study existing and uncover entirely new dimensions of the human condition.

Eric: The Cube is a very rare kind of performance space in the world today. It may surprise you that one of our goals is to become a rather more common performance space in the future, as similar facilities continue to be built throughout the world. We have seen this rare-to-common progression in both the analog tape music studios of the 1950s and the computer music labs of the 1960s. Most HDLA facilities like the Cube were built in the 21st century, so we may still be near the beginning of a similar trend. It’s possible that there will be faster build-out in the commercial space, compared to the experimental space, considering the recent growth of the Dolby Atmos system, which currently supports up to 64 channels, and is being deployed to movie theaters and other spaces, including home theaters. Music and sound for HDLAs remains an experimental domain, and one of the defining features of experimental initiatives is that you never know in advance exactly how things are going to shake out.

Anything else you would like to add?

Ico: Thank you for this opportunity. It’s been a pleasure interacting and sharing exciting milestones made possible by the unique infrastructure found at Virginia Tech.