Octave 9, designed by LMN Architects
Benjamin Benschneider Octave 9, designed by LMN Architects

Located along one of Seattle’s most prominent cultural corridors, Octave 9 is an intimate, 2,500-square-foot experimental performance space within Benaroya Hall, home to the Seattle Symphony. Designed by local firm LMN Architects—also the authors of the original 1998 building—the venue employs cutting-edge audiovisual technologies with custom-fabricated details to achieve what the firm calls “electronic architecture”: a programmable and fluid environment largely able to accommodate the particular needs of any performance uncoupled from the room’s dimensions and materiality.

“Part of the initial efforts of the project was to figure out what does it mean for the symphony to want to be the ‘orchestra of the future,’ and how are we going to design this space to help facilitate that?” says Scott Crawford, Assoc. AIA, a principal at LMN Architects and a founding member of LMNts, the firm’s technology studio.

As a result, the venue is equipped with a digital acoustic constellation sound system from Meyer Sound that can be reconfigured and tuned by moving any of the 13 curved screens suspended from a ceiling track. But the space also needed to feel distinct, to have a visual identity that complemented its mission.

Instead of having “all the guts hanging out on the ceiling” as is common in black box theaters, Crawford says, Octave 9 features a sculptural ceiling composed of hundreds of irregularly shaped “cells” that absorb sound and conceal many of the requisite systems. The cells are made out of digitally fabricated acoustical panels ranging in depth from 4 inches to 16 inches. (The ceiling is mostly between 8 feet and 9 feet high.) Felt-like in appearance and touch, the panels are actually PET plastic sourced from the local company Snap-Tex and contain up to 60 percent recycled content. The cells join together like puzzle pieces, forming approximately 6-foot-square modules that hang from a Unistrut system.

Octave 9, designed by LMN Architects
Benjamin Benschneider Octave 9, designed by LMN Architects

LMN’s design approach continues a line of inquiry involving parametric modeling that it first explored at the University of Iowa’s Voxman Music Building, in 2016. But the smaller Octave 9 project is far more complex due to its unique program and existing structural constraints; for example, a load-bearing column sits a few feet from the middle of the performance space.

The biomorphic form of Octave 9’s ceiling was also derived from the underlying grid of several audiovisual systems, such as lights and microphones, combined with the radial configuration of special projectors and a few hands-on designer tweaks. Using Grasshopper and the gist of a Voronoi diagram, the design team assigned every element in the audiovisual system a minimum amount of clearance and allowed those diametrical assignments to exert a certain amount of pressure. “The projectors put more ‘pressure’ on the area around them, which causes the cell to inflate and compress the ones around it,” says Crawford, who developed the algorithm. “The microphones exert very little pressure, because, in the end, they’re smaller in diameter than your pinkie.”

Reflected ceiling plan
Courtesy LMN Architects Reflected ceiling plan

In this way, the ceiling’s 3D, cell-like shapes were not designed so much as generated. Its intricate pattern was never actually drawn. “The locations [of systems] and the geometry of the beams in the space directly influence the formation of the undulating surface on the underside of the ceiling,” Crawford says, and the final form “emerged out of the simulations that we were running.”

The project also offered another first for LMN: the opportunity to fabricate the final acoustical product. “[W]e decided that we were going to build it ourselves, not only because we thought it would help streamline the design-to-fabrication process, but also because it would be a good learning process for us,” Crawford says.

The team underestimated how much they would learn. The architects had created drawings of each individual cell in its “unfolded” state, creating long geometric panels that could be CNC-milled from Snap-Tex’s standard 4-foot-by-8-foot, 0.5-inch-thick sheets. The shortest panel was just 3.25 feet. The longest run, which ganged two sections, was 10.5 feet. Using Grasshopper, the team could fit up to seven panels per sheet.

Acoustical cell panel breakdown
Courtesy LMN Architects Acoustical cell panel breakdown

During a six-week takeover of LMN’s in-house fabrication shop, the designers ran into innumerable challenges. For instance, the CNC machine’s metal bit cutting into the panels’ felt-like material would regularly overheat, subsequently melting the plastic fibers. The designers devised a custom air-delivery system, blasting the bit with a constant stream of cool air via an air compressor attached to the CNC machine’s arm. This fix also “helped blow [away] the material as it was being cut,” Crawford says. Because the cut edges were left slightly frayed, the visible side of each panel was hand-ironed on a low setting to smooth its appearance. LMN fabricated the ceiling in approximately six weeks.

Local general contractor JTM Construction installed the ceiling system, in part because LMN’s general liability insurance did not extend to on-site construction. Because some acoustical cells only attach to neighboring cells and not the Unistrut system, the architects created a color-coded sequencing diagram to guide the installation process. Adjacent cells were pinned together with clear plastic binding posts and hung using an aluminum angle that slips between the “walls” of the cell. Each module weighs at most 30 pounds, Crawford says. Altogether, the ceiling uses 4,000 square feet of acoustical panel and weighs less than 2,000 pounds.

Section through acoustical system attachment to ceiling
Courtesy LMN Architects Section through acoustical system attachment to ceiling

Crawford found the process of figuring out how to create and realize a design both fulfilling and daunting. “[T]here’s actually a lot more to be gained as a designer when you start entering into these moments.” Even the challenges, he adds, became “fun distractions—ways of keeping yourself mentally engaged when you’re having to do something 200 times."

Octave 9, says LMN design partner Mark Reddington, FAIA, was an “opportunity to be hands-on” and learn about fabrication in a real-world scenario. Moreover, the project helped him envision how technology will allow architects to embed themselves into the construction process—a fundamental question to the future of the profession.