Proceedings of the Institute of Acoustics

DESIGNING SYSTEMS TO DELIVER SUCCESSFUL IMMERSIVE AUDIO EXPERIENCES B McCarthy Meyer Sound Laboratories, Incorporated. S Ellison Meyer Sound Laboratories, Incorporated. 1 INTRODUCTION

Immersive audio experiences, once primarily the privy of high budget theatrical productions, are becoming more mainstream and entering the general public’s consciousness. 1 New tools, such as Meyer Sound’s Spacemap Go, put spatial audio control at the fingertips of musicians and audio mixers, not just theatrical sound designers and audio researchers. This gives both small clubs and large venues the potential to create dynamic immersive audio experiences with less technical skill than previously required. Many of these tools, such as Spacemap Go, are format agnostic. These provide a spatial mix technique but do not specify how to design the systems that they control. There is a large body of work and collective experience to help designers create mono, stereo, and Left/Center/Right (LCR) sound reinforcement systems. But what of the immersive audio loudspeaker system? 2 SYSTEM DESIGN

2.1 Listening Environment

Immersive audio may be experienced in many environments. 2 The most common goal is to create a multichannel sound field in which the listening area is maximized, and multiple listeners simultaneously experience a similar multidirectional audio environment. Rooms with relatively low reverberation times as well as outdoor venues will provide better localization to the sound source, as projected by one or more loudspeakers. Cinema-like acoustics are recommended so that the audio cues provided by an electroacoustic system are preserved, rather than cathedral-like acoustics that can provide an immersive sound environment for a single acoustic sound source but can easily mask the spatial audio cues provided by a multichannel loudspeaker system. Strong specular reflections should be avoided because they are perceived as secondary sound source locations and will therefore interfere with spatial mixing. 2.2 Loudspeaker System Design

In practical systems loudspeakers produce different levels at different distances and angles. In many panners it is possible for a signal to be routed primarily to a single loudspeaker. In such systems it is beneficial to select each loudspeaker position, orientation, and coverage angle to produce the most uniform level over the greatest area of audience. For overhead loudspeakers this leads to selecting a loudspeaker with wide coverage in all directions at a height which is on the order of the length or width of the audience area. For lateral loudspeakers this leads to selecting a loudspeaker with wide horizontal coverage but narrow vertical coverage so that the increase in level experienced by close listeners is mitigated by a reduction in level by being off axis (but still inside the rated coverage). The height and orientation of lateral loudspeakers should further be coordinated so that the closest intended listeners are at the bottom of vertical coverage. This paper describes a practical method of system design that provides consistent coverage for rooms of arbitrary size by defining a new unit of measure. To add some fun and engagement to a topic which would otherwise be a matter of rote geometry and trigonometry, we call this unit the Go

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Distance, or more simply just the Go. It will be shown that the resulting lateral height, lateral spacing, overhead height and overhead spacing are all given by a multiple of Go. The resulting area, where all listeners are in coverage of all loudspeakers, is called the Go Zone. 2.3 Go Zone and Go Distance (Go)

The proposed approach uses room geometry to determine some of the key metrics for loudspeaker location, height, spacing, pan and tilt. These are derived from the room interior dimensions, specifically the outer limits upon which loudspeakers can be located, the walls and ceiling. A secondary parameter is the audience listening area, which does not necessarily reach the walls. The optimal immersive coverage area is where all listeners receive coverage from every loudspeaker in the multichannel system. How can we evaluate whether we have created an immersive experience? We can go to the room center and conclude that we are surrounded with sound. But that is just a single position. We know that at the outer edge there will be no such immersion. Physics prohibit it. The mid-point between the center and the outer limits will be our starting point. This central subset of the space is used to guide loudspeaker placement, spacing, aim and height. We refer to this area as the Go Zone. The Go Zone is primarily a design construct and is not the exclusive area for effective immersive coverage. If these guidelines are followed, highly effective immersive experiences far beyond the Go Zone perimeter can be achieved. When lateral loudspeakers are mounted on the outer walls, as in Figure 1, the distance (D) between laterals on opposite sides defines the enclosed area where the loudspeakers operate.

Figure 1. Go Zone and Lateral Placement. (A) Establishing the Go Zone and Go Distance in a flat square space. (B) Go Zone and Go Distance in a rectangular space. (C) Section view showing height considerations using the Go Distance. (D) Lateral system spacing using the Go Distance. There are five front loudspeakers in this example and therefore they are spaced at 0.5 x Go.

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Proceedings of the Institute of Acoustics

The Go Zone (in a square room) will be a square with half-size lengths, a square within the larger square. The Go Distance (Go) is the distance from the edge of the Go Zone to the loudspeaker perimeter, and is given by:

Consider a square room with a 10 m distance between the opposite side loudspeakers. This 10 m square yields a 5 m square Go Zone and Go Distance of 2.5 m. In rectangular rooms the Go Zone will be rectangular. Go is derived from the narrowest side and subtracted from both dimensions. A 15 m x 10 m loudspeaker rectangle results in a 10 m x 5 m Go Zone and a Go Distance of 2.5 m. Go Zone and Go Distance are fully scalable to both large and small spaces. 2.4 Loudspeaker System

 

Our design intent is to create a 3-D sonic environment where listeners can perceive sound images in unique locations. The image can be static or mobile—able to freely move around the horizontal and vertical planes. The loudspeaker system design is comprised of three general components: “full range” loudspeakers, subwoofers, and signal processing. This section details how the 3-D sonic environment design is achieved using these components. 2.4.1 Conceptual Approach

The typical approach to sound reinforcement system design is to carefully subdivide the coverage with a goal of minimizing the loudspeaker overlap and leakage outside of the listening area. This approach maximizes intelligibility and uniformity and minimizes the destructive interference (comb filtering) caused by correlated signals arriving from different loudspeakers or reflecting off walls. The proposed design guidelines differ from the sound reinforcement approach regarding loudspeaker overlap. 2.4.2 Loudspeaker Characteristics

The loudspeaker can be characterized in simplified form by three parameters: (a) frequency range, (b) horizontal and vertical coverage and (c) power scale. We are considering two distinct loudspeaker types: “full range” (c. 60 Hz to 18 kHz) and subwoofer (c. 30 Hz to 120 Hz). These are divided into two categories without concern for precise differences such as the low frequency cutoff of a full range loudspeaker. For the full range loudspeakers, it is expected they will provide independent horizontal and vertical directional control of higher frequencies. Highly overlapped coverage is recommended. Therefore, the standard full range loudspeaker element is as wide as practical in the horizontal plane. The optimal width is 110° and the minimum width is 80°. Subwoofers are considered omnidirectional and therefore their directivity will not be discussed further. Most lateral elements benefit from a medium vertical directivity of between 40° and 50°. This directivity helps the lateral sources reach the opposite side without being too loud on the near side. Overhead elements typically use wide directivity but can also use medium vertical loudspeakers when the room is more rectangular and/or their placement is relatively low. The power scale of laterals and overheads must be proportional to the main system. If the laterals and overheads are expected to operate at an equivalent SPL as the mains, then they must be comparably scaled. However, surround systems are typically scaled 6–12 dB below the mains and

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can be less if the signals are low level program material such as environmental sound effects in a theatrical production. 2.4.3 Lateral Loudspeaker Placement

We perceive horizontal panning more acutely than vertical panning. Therefore, a frontal system might benefit from five or more discrete horizontal channels but not five vertical channels. Lateral surround loudspeakers are the most important spatial panners when moving the sound beyond the front and should form an evenly spaced sonic perimeter. Each lateral loudspeaker is horizontally aimed to the center of the listening area and vertically aimed to maximize uniformity. This provides the designer with an immersion palette that can effectively steer the sound around the entire 360° sonic perimeter. Each lateral loudspeaker is intended to cover the maximum width and depth. In the physical sense, the side surrounds are a spaced series of loudspeakers along the wall. When designing sound reinforcement systems, we usually think of such a configuration as an array, specifically, an uncoupled line source. 3 But instead of designing the spacing and aim to minimize overlap to accommodate a shared correlated signal (as found in front fills or under balcony loudspeakers), our goal instead is to maximize overlap to accommodate multiple unshared, uncorrelated input signals. In short, every loudspeaker location is an individual sound source. Signals are mixed primarily in the air, rather than in a single loudspeaker. We suggest that for sound to be perceived as lateral, it must reach the listener at an angle no greater than 45° above the listener’s ear. The maximum lateral height is therefore 1 x Go above the listening plane, resulting in a vertical angle of 45° as sound enters the Go Zone. The minimum recommended height is 0.5 x Go, resulting in an angle of 22.5°. The higher lateral position can cover around 75% of the space within a 6 dB window of level variance, and around 75% of the audience will receive the audio from an angle of 45° or less. By contrast, the lower position covers just 25% within 6 dB, and around 87% of the audience in the Go Zone will receive audio from an angle of 45° or less. The tradeoff is therefore coverage versus image height. We recommend that coverage take priority because, especially in an event experienced by many people, the image is irrelevant if the audience cannot hear it. Both coverage and image can be maximized by implementing the higher position and adding a small fill loudspeaker at the low position for audience members at or beyond the edge of the Go Zone. Lateral loudspeaker placement can begin with the front center position. The spacing to the next front lateral is equal to 1 x Go, 2.5 m in our example. This provides three front elements spaced at 2.5 m intervals across the front. This is mirrored for the rear laterals along the back wall. The furthest off- center front and rear loudspeakers line up along the Go Zone edge. Next, consider the side laterals and use the same 1 x Go spacing. Start with the most forward lateral position 0.5 x Go in front of the Go Zone and locate the rear-most lateral 0.5 x Go behind the Go Zone. This provides a set of four side laterals on the left and right respectively, and each set is centered on the wall on which it is located. These lateral positions provide a “14-hour clock” with which we can evenly move sound around the room. This spacing creates a series of overlapping –3 dB points along the Go Zone perimeter, assuming 90°–110° wide loudspeakers are used. Because the “normal” spacing for unity gain summation is given by the -6 dB points, 3 we essentially have 3 dB of “immersion” at the entry to the Go Zone, and more beyond. Return for a moment to the front loudspeakers. What if five elements are desired instead of three? These can be added to evenly fill the same space, with 1.25 m spacing. If four elements are desired, then the spacing is 1.67 m and there is no center channel.

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2.4.4 Lateral Loudspeaker Aim

There are two aspects of lateral aiming: horizontal and vertical. Recall the goal that each loudspeaker element is to cover as large an area as possible on its own. Therefore, we aim each one as if it is the only loudspeaker in the room. In the horizontal plane, all aim through the center (also the center of the Go Zone). The vertical aim is also easy to determine. Aim the centerline of the loudspeaker to the farthest listener on the opposite side. 2.4.5 Overhead Loudspeaker Placement

The traditional approach to overhead system design is based on a monaural signal sent to evenly spaced loudspeakers aimed straight down, such as an announcement system at an airport. The spacing is set to minimize overlap, thereby maximizing intelligibility. By contrast, the design intent of our immersive overhead system goes beyond speech delivery or simply making people look up. The immersive overhead system can also provide horizontal movement within its raised image. Simply put, while the laterals allow us to fly a helicopter around the room at low altitude, the overheads can continue the circular journey upward. Let’s start with a single overhead loudspeaker facing straight down from the center of a square space. This single source can cover the entire room if raised high enough. A loudspeaker with 110° horizontal and vertical coverage at a height of 2 x Go above the listening plane would accomplish this. All listeners would identify this image source as “high center.” As we move the loudspeaker off center, the image moves horizontally but remains high. With four such sources we can pan the signal between them and make circles in the air. We do not even need a center loudspeaker to create the “high center” image. This can be achieved by summing the four loudspeakers together. As will be shown later, this image is achieved in Spacemap with a Virtual Node. Loudspeaker height will determine both its effectiveness and spacing. If too low, the loudspeaker cannot reach distant areas without overpowering nearby listeners. If extremely high, the angular range of image movement will be minimized. As shown in Figure 2, the most effective range is between 1 to 2 x Go Distances above the listening plane. These yield >50% and >75% coverage, respectively.

Figure 2. Overhead Loudspeaker placement. (A) Section view comparison of 1 x Go and 2 x Go height. (B) Plan view showing spacing at 2 x Go height, which requires only four elements. (C) Plan view showing spacing at 1 x Go height, which requires nine elements. The recommended spacing between the overheads is the same as their height above the listeners. A height of 1 x Go yields spacing of the same amount and likewise for 2 x Go or numbers between. It can be advantageous to place a loudspeaker in the center overhead position at low heights but less so at higher heights. Returning to the example Go Distance of 2.5 m in our square room, we can place four loudspeakers 5 m above the listeners and 5 m apart using 2 x Go height and spacing.

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Notice that the overheads are not placed on the outside walls (like the laterals). They are instead over the Go Zone perimeter. There is no need to place them at the far reaches because listeners on the outer edges are already perceiving the laterals as above them, as the laterals are functioning as overheads on the outer edge. It will not help to have two loudspeakers stacked above each other, so we can reduce cost and complexity by resisting redundancy. 2.4.6 Overhead Loudspeaker Aim

The horizontal aim for the overheads follows the previous method: aim inward to the opposite side through the center. The vertical aim, however, differs because we are not originating our path from the outside wall. The most consistently effective aim to maximize coverage is to target a listener location 0.5 x Go beyond the center. The coverage will typically spread both under and beyond that location without sending too much energy to the opposite wall or missing the listeners below. Resist the temptation to aim the loudspeakers straight down, as this method is only effective for a mono vertical plane rather than a mappable vertical palette. Lateral as well as overhead design parameters are summarized in Table 1, where Go is the Go Distance. Table 1. Determining design parameter values

Design parameter Minimum Maximum Ideal

First Lateral offset 0.5 x Go 1 x Go

Lateral spacing 1 x Go

Lateral elevation 0.5 x Go 1 x Go

Overhead elevation 1 x Go 2 x Go

Overhead spacing Overhead elevation

2.4.7 Low Frequency Loudspeaker Systems (Subwoofers)

Subwoofers installed in the front of the room (such as used in a concert application) should be designed for maximum power coupling with the main loudspeaker systems. Priority must be given to reproducing drums and other transient signals and to minimize low frequency leakage on to the stage. The surround subwoofer systems are designed to expand the spatiality of the LF range without sacrificing the low frequency performance of the front systems. The surround LF system can use both laterals and overheads but does not have a large role in helping generate spatial audio cues. Localization is much stronger in the HF range, allowing us to minimize the number of low frequency devices, channels, and locations. The singular subwoofers are assumed omnidirectional and therefore coverage essentially follows the inverse square law. In the best case, they are flown at the level of the laterals. In the worst case (and often the reality), they are on the ground. The customary practice is to place subwoofers in the corners to provide lateral movement (square spaces) or six locations (corners and sides) in a rectangular room. Overhead subwoofers are effective for flying helicopters. A single overhead location adds power to the experience and each additional unit enhances the possibility of plausible full range spatialization. 2.4.8 Signal Processing

Each loudspeaker location requires a unique signal processing channel. This strategy ensures that transitions between locations are smooth and continuous. This fully granular configuration differs from a conventional 5.1 cinema approach in which the side and rear surrounds are treated as a block. This approach allows a source to be continuously panned around the listening area. Each processing

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channel will have a unique level, equalization, and delay to best align the loudspeaker to match the other elements. 2.4.9 Additional Considerations

The approach outlined here is a starting point of an immersive loudspeaker system design. Not all rooms are single-level squares with flat floors. More complex shapes, such as multiple levels, balconies, and box tiers, for example, require us to think outside of the literal box we have outlined. In general, such complexities reduce the percentage of listeners that can experience full immersion. Nonetheless, there are design strategies that provide some measure of spatialization into these challenging areas. Unfortunately, a discussion of these strategies is beyond the scope of this paper. 3 EXAMPLE SYSTEM DESIGN

3.1 Loudspeaker System

We will now consider a system installed in the Noble Room at the Jazz at Lincoln Center complex in New York City. 3.1.1 Room Geometry

The exterior walls are 7.2 m square, resulting in outer limits of 6.4 m x 6.4 m for lateral loudspeaker placement, as shown in Figure 3. This yields a Go Zone of 3.2 m x 3.2 m and a Go Distance of 1.6 m. The ceiling allows loudspeakers to be placed at a maximum height of 4.0 m. This is 2.8 m above the seated listeners, so clearance is just less than 2 x Go.

Figure 3. (A) Noble Room layout showing loudspeaker perimeter, Go Zone and Go Distance, (B) Lateral and overhead loudspeaker layout, (C) Horizontal aim, (D) Vertical aim.

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3.1.2 Loudspeaker System Elements

The lateral loudspeaker has a coverage pattern of 110° horizontal x 50° vertical. This provides at least 3 dB of horizontal overlap at the entry to the Go Zone and provides effective spatialization. The narrower vertical coverage helps the loudspeakers reach deep across the room without overpowering the near listeners. The overhead loudspeakers have a wide coverage pattern of 110° in both planes. This provides a wide circle of coverage extending from deep under the loudspeaker to the opposite side. 3.1.3 Lateral System Placement and Aim

The lateral loudspeaker spacing is given by Go, 1.6 m. The front loudspeakers use five elements spaced 0.8 m across the 5 m length. The rear loudspeakers use three elements at the standard spacing of 1.6 m. The side systems use four elements at the standard spacing over the 4.8 m spread. The lateral system height is set at 0.75 x Go, which is 2.4 m, 1.2 m above the listeners. The lateral loudspeaker horizontal aim target is the geometric center. The vertical aim target is the farthest listener and ranges from 9°–11°. Figure 4 demonstrates the horizontal coverage for four of the lateral loudspeakers and illustrates the uniformity that can be achieved using Spacemap to pan between four adjacent loudspeakers. All loudspeakers are at the “medium” height.

Figure 4. Noble Room horizontal coverage for four of the lateral loudspeakers. The red area is within a 6 dB level variance and represents “in coverage.” 3.1.4 Overhead System Placement and Aim

The overhead loudspeaker height is set at the maximum available height of 4.0 m, 1.8 x Go, which is 2.8 m above the listeners. This is just short of the ideal height of 2 x Go, 3.2 m above the listeners. The spacing is 3.0 m, halfway between the desired (3.2 m) and actual (2.8 m) heights above the listeners. The four loudspeakers are almost directly over the corners of the Go Zone.

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The overhead horizontal aim target is the geometric center. The vertical aim (-45°) focuses down and intersects the listening plane at approximately 0.5 x Go past the center. Figure 5 illustrates how coverage expands with elevation for several examples.

Figure 5. Noble Room coverage comparisons for three different heights of a lateral and overhead loudspeaker. (A) Center lateral at low height (0.5 x Go), (B) Medium height (0.75 x Go), (C) Maximum height (1 x Go), (D) An overhead at minimum height (1 x Go), (E) Medium height (1.5 x Go), (F) Optimum height (2 x Go). 3.2 Spacemap Go

Spacemap Go is used to mix up to 32 separate input channels to the installed loudspeaker system in the Noble Room. Spacemap Go is an iPad software application that uses the Spacemap algorithm to control one or more Meyer Sound GALAXY signal processors configured as a multi-channel mix matrix. Touch controls allow users to place sound sources within the Spacemap, record and play back sound trajectories and store and recall snapshots. While designed for live control during a performance, automated workflows that integrate with Digital Audio Workstation and theatrical sound design software are also supported. 3.2.1 Spacemap

Spacemap is a multichannel amplitude panning algorithm originated by LCS Audio. It has been available in commercial products since 1993, 4 implemented as a set of software objects for Max/MSP and Pure Data in 2014, 5 and most recently incorporated into Meyer Sound’s Spacemap Go iPad app in 2020. Spacemap distributes power to nodes arranged in a triangular mesh. Power within an individual triangular region of the mesh, or “Triset,” is distributed to its three member nodes via aerial barycentric coordinates. These nodes are either an individual loudspeaker (“Speaker Node”), a group of loudspeakers (“Virtual Node”), or null (“Silent Node”). Further, loudspeakers that are not part of the mesh can receive power from other loudspeakers in the Spacemap. The “Spread” control distributes the desired percentage of power to all loudspeakers in the Spacemap. The “Crossfade” control enables the linkage of two unique Spacemaps. This feature provides power-preserving panning as it transitions between the XY positions of the two unique Spacemaps (e.g., an upper and lower

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Spacemap). Spacemaps preserve power, provide continuous control and are scalable for systems with a few loudspeakers to those with well over a hundred. 3.2.2 Spacemap Design

Spacemap does not prescribe loudspeaker positions. Rather, Spacemap design is guided by the configuration of the loudspeakers in the system. Spacemaps can be designed that are primarily representational, in which the node layout resembles the loudspeaker layout, or more abstract, in which the node layout may not reflect the actual position of the loudspeakers in the system yet supports a specific mix strategy. 6 An example of a representational Spacemap is a quad panner constructed using Speaker Nodes in the four corners and a Virtual Node in the center that receives its power from the linked corner Speaker Nodes. This Spacemap will include four Trisets that distribute the power to the corner nodes. A simple abstraction is to lay out the Speaker Nodes for a set of lateral loudspeakers that are located on the walls of a rectangular room as a ring of nodes rather than as a rectangle. This facilitates smooth panning using circular trajectories. Another abstract example is a Spacemap designed to control a multi-channel colinear system, where the X axis controls the position along a line of loudspeakers, and the Y axis controls the number of adjacent loudspeakers to which power is distributed. In this case, while the Speaker Node positions are laid out in a similar fashion as the loudspeakers in the room, the panning surface of the Spacemap is largely created with Virtual Nodes that specify the desired power distribution. Spacemaps can be designed that incorporate both representational and abstract elements, such as a Spacemap that supports width and position control for a colinear frontal system using the top area of the Spacemap and a group of lateral side and rear loudspeakers using the bottom area. Because unique Spacemaps can be assigned to individual channels, they can be selected for specific content and the spatial mix intent for that content. Spacemap examples are provided in the next section. 3.3 Spacemap at the Noble Room

The Noble Room is used to demonstrate spatial audio for a wide range of uses. Content includes a series of automated theatrical sound effects, multichannel music stems, and live sources that can be patched into the system via an audio mix console. A Spacemap that represents a top-down view of the system is shown in Figure 4. The perimeter of this Spacemap includes Silent Nodes (red) to provide smooth fades into the panning area. Virtual Nodes (orange) distribute power to linked Speaker Nodes (blue). A set of four Subwoofers receive signal automatically via Derived Nodes (green) that are linked to nearby Speaker Nodes. In this example, power is distributed to three Speaker Nodes that include two lateral and one overhead loudspeaker as well as the Derived Node for the nearby subwoofer. Halos around Speaker and Derived Nodes are drawn in proportion to the amount of power distributed to them. A linear pan from left to right in the center of the Spacemap will cause the sound to fade in at the left laterals, pan up to the overhead loudspeakers, pan through and across the overhead loudspeakers, and then pan down the right laterals and fade out. This Spacemap can also be used to circumnavigate the lateral loudspeakers by moving in the perimeter of the Spacemap or pan around the overhead loudspeakers by moving in a closed circle in the center area.

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Figure 4. A “Top-down” Spacemap provides access to all loudspeakers in the system. Another technique, shown in Figure 5, illustrates how vertical panning can be achieved by assigning a pair of Spacemaps to a channel and using Crossfade to smoothly transition between the two Spacemaps. The two input channels shown below have each been assigned the same two Spacemaps. One Spacemap addresses the lateral loudspeakers and the other addresses the overhead loudspeakers. The Crossfade control, set differently for these two channels, sets the apparent elevation of the sound source. The interface displays the Spacemap receiving >50% of the signal from the channel.

Figure 5. A pair of Spacemaps are assigned to Channels 3 and 4. The system incorporates five loudspeakers in the front, and Figure 6 shows how signal can be mixed either to an individual, pair, or group of three, four, or five loudspeakers. In all cases, power is preserved so the diffusion characteristics are adjusted in the system without changing the amount of energy in the room. The Virtual and Silent Nodes can be hidden for operator clarity, as shown in Figure 6, right.

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Proceedings of the Institute of Acoustics

Figure 6. “Colinear Front” Spacemap with five front loudspeakers (1-5) and two subwoofers (6-7). These three distinct techniques can be applied on different input channels at the same time within the system. Snapshots allow for smooth transitions between both static positions and dynamic positions set in motion via pre-recorded trajectories. 4 DISCUSSION

There are several factors that can influence the application of these design guidelines to create an achievable system for a given room. These may include architectural and installation challenges. It may be difficult to mount and aim loudspeakers overhead, let alone run cables to these locations. Lateral positions may be limited by architecture as well, and budgets may preclude achieving the desired lateral density. However, even with these challenges, the motivated system designer can optimize an installation if the desirable characteristics for loudspeakers are understood. For instance, a lateral system can be designed with excellent coverage that provides a large area of lateral immersion for audience members, even if an overhead system cannot be installed. And while higher density lateral systems can provide greater spatial resolution than lower density systems, low and medium density systems will work if appropriate loudspeakers are installed to maximize their coverage and uniformity. Applications like Spacemap Go bring the potential for creating Immersive Audio Experiences to a much wider audience than ever before. By applying concepts accepted in sound reinforcement system design to immersive sound system design, we can create systems that maximize the immersive coverage area and simplify the creation of a successful immersive experience. 5 REFERENCES

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1. S. Ellison, “Industry POV: Spatial Sound Is Transforming Attractions,” Sound and Communications (2021) 2. S. Ellison, “Sound in Space,” Sound and Communications (2018) 3. B. McCarthy, Sound Systems: Design and Optimization, Focal Press (2017) 4. S. Ellison, “SpaceMap: 20 Years of Audio Origami,” Lighting and Sound America, 80-88 (2013) 5. Z. Seldess, “MIAP: Manifold-Interface Amplitude Panning in Max/MSP and Pure Data,” 137 th Convention of the Audio Engineering Society (2014). 6. E. Bates, “SpaceMaps, Manifolds and a New Interface Paradigm for Spatial Music Performance,” BEAST FEaST 2015. Birmingham (2015).

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