Meyer Sound Documentation

Nodes are the points that audio is panned to within a map. They can represent physical loud- speakers (Speaker nodes) or simulate an output location (Virtual nodes). Nodes can also derive their audio from other nodes (Derived nodes), or discard their audio completely (Silent nodes). These types are defined in “Types of Nodes” on page 135.

Trisets are triangular panning surfaces defined by three nodes. They ensure a smooth pan without signal drop, like a two-dimensional panning law used by a conventional pan pot. Just as two points are the minimum required to define a line, three points are the minimum required to define a plane.

CAUTION: Trisets cannot overlap one another: signal distribution would be unpredictable within the overlapped areas. An overlapping Triset turns red as a

warning.

NOTE: In circumstances where a single loudspeaker is included in a SpaceMap Triset twice—once as a Triset node, and again as a Derived Node linked to one of

the Triset nodes—CueStation now interprets the two inclusions to make the output level a sum of the two roles’ output levels.

The size of the Triset is not critical because the power-preserving panning law is proportional rather than absolute. It is based on the relative distance between the spatial pan control and each of the three surrounding nodes, rather than the actual physical distance within the grid.

The path along which a sound moves is called a Trajectory. A trajectory can be recorded, edited, and reshaped, then mapped to an input bus and recalled as part of a SpaceMap Tra- jectory subcue.

Trajectories can create the illusion of a moving sound, fade sounds in and out, or control a variety of other effects depending on the design of the map. The relative position of the SpaceMap bus within a Triset determines the proportion of signal sent to each of the nodes in the Triset. The actual signal levels can be seen in the Matrix window, along the row of the input bus assigned to the control.

Each trajectory is an entirely independent entity, with no absolute relationship to any one map. One map can have several different trajectories, or one trajectory for several different maps. Several trajectories can be active at once (one per bus), and there can be an arbitrary number of trajectories (and maps) in a project file.

Additionally, a trajectory can be played back with real-time modifications, such as the number of repetitions, rate, orientation, scaling, and offset in both X and Y dimensions. Several copies of the same trajectory could be assigned to different buses and performed simultaneously with different modifiers on each.

Trajectories are comprised of Trajectory nodes. Where Trisets represent loudspeaker locations and establish points from which to derive relative panning, Trajectory nodes represent the cur- rent position of a signal in each plane.

Trajectory Nodes

Each TrajectoryNode contains information on both temporal and positional axes, and can have a level setting independent of the Trajectory’s level. In addition, nodes can be named and can recall text commands.

Speaker nodes represent the physical outputs in the D-Mitri system.

Triset Containing Speaker Nodes

Each speaker node is assigned to a single output. Outputs can be connected to loudspeak- ers, effects processors, or any other devices. Multiple nodes can be assigned to the same output. When a Triset contains three Speaker nodes, the audio is distributed amongst the nodes as determined by the location of the bus or trajectory within the Triset, and the relative distance between the nodes. For more information on how to create these nodes, see “Add- ing Nodes” on page 146 and “Creating Trisets” on page 147.

A Virtual Node simulates a physical output in space by distributing its signal to the Speaker nodes to which it is linked.

Virtual Node Simulating the Center of a Quadraphonic SpaceMap

By default the signal is divided equally among all the linked Speaker nodes, but proportional Link Gains can be defined that change the balance of the distribution. For more information on how to create these nodes, see “Adding Nodes” on page 146.

In this example, the Virtual Node is linked to the four Speaker nodes so that any signal that is assigned to it is equally distributed among the surrounding loudspeakers. Thus a trajectory traveling around the perimeter of the map pans linearly from one loudspeaker to the next, but a trajectory that moves toward the Virtual Node at the center of the map causes the signal to spread out to all four loudspeakers gradually. This proportional distribution method creates a convincing phantom image throughout the panning area.

A Silent Node takes part in a Triset in place of a Speaker Node but it is not associated with an output.

Silent Nodes Providing Fade Thresholds to a Quadraphonic SpaceMap

A signal panned toward a Silent Node simply disappears, providing an easy way to create fade-in and fade-out effects. This feature also solves the signal dropout problem that exists when a trajectory strays outside the panning area defined by a Triset of Speaker nodes. Since the area outside the map is currently undefined, the signal abruptly drops out. By surrounding the existing map with Silent nodes, we can create a perimeter of fadeout Trisets and guard against unintended loss of signal.

For more information on how to create these nodes, see “Adding Nodes” on page 146.

To complete our model, place four Silent nodes, one outside each side. Create Trisets, each with two Speaker and one Silent Node, or two Silent and one Speaker Node. The Speaker nodes entirely enclosed within Trisets, sound panning is now gap-free.

The Derived Node provides a way to send a signal to a secondary output whenever that signal is also being sent to a set of Speaker nodes.

Derived Node Providing a Mono Sum Output in a Quadraphonic SpaceMap

Derived nodes link to one or more Speaker nodes, and receive a sum of the signals from its linked Speaker nodes. Each link between Speaker nodes and Derived nodes can be adjusted in decibels, from -89 dB to +10 dB.

Derived nodes are commonly used for subwoofer sends, fill mixes, balconies, and other cases where a secondary mix-down of a multichannel mix is required. For example, a Derived Node feeding a single subwoofer would be linked to all the main channels, so that the subwoofer receives a constant feed even if the source signal is being panned. For more information on how to create these nodes, see “Adding Nodes” on page 146.

By default, Virtual and Derived nodes distribute and receive, respectively, an equal proportion of the signal of their linked nodes. Link Gains allow the alteration of these proportions.

When selecting a Virtual or Derived node and its one or more linked nodes, the amount of linked gain can be changed using the Set Link Gains command (see “Setting Link Gains” on page 149).

Link Gains for Virtual and Derived nodes are expressed in decibels, with a maximum value of

+22.1 dB. Any number that is entered, down to -90 dB, is considered negative unless it is pre- ceded by a + sign.

Most of the SpaceMap window is devoted to a drawing area. This is where nodes are placed and linked, Trisets created, and trajectories are drawn.

TIP: The display scaling can be decreased with Command+[ (Mac) or Ctrl+[ (Win- dows), and increased with Command+] (Mac) or Ctrl+] (Windows). The display

can be re-centered using the scroll bars.

Grid settings

There are two different grid options: Cartesian and Polar. The displayed grid type and size can be changed in the Display menu.

For cleaner-looking maps and trajectories, choose Display > Snap to Cartesian Grid or Display

> Snap to Polar Grid.

Directly below the SpaceMap grid view is a row of buttons for selecting different editing tools. As they appear from left to right, the buttons offer the following functions.

Below the SpaceMap grid area, there is a set of trajectory playback controls. The text box dis- playing a time in milliseconds shows the position of the bus along the trajectory, relative to time. The transport controls include the following.

Transport controls can be shown and hidden through the Display menu.

This section of the window contains the SpaceMap automaton settings for each bus.

The following parameters are visible when Display Show Playback Details is enabled. These parameters control how a bus moves along the selected trajectory, but do not affect the actual trajectory. They are not saved with each SpaceMap or Trajectory.

Choose Display > Show Trajectory Editor to view the Trajectory Editor.

Trajectory Editor

The trajectory editor shows a timeline view of the currently selected trajectory. A drop-down menu in the upper left changes the Trajectory Editor display between Level, Pan, or Diver- gence of each TrajectoryNode. Across the top are buttons for scroll to start, scroll left, scroll right, scroll to end, zoom in, zoom to fit, and zoom out.

These controls affect the actual trajectory, and the parameters affect all buses that uses the trajectory.

These settings change the appearance and behavior of the background grid through the Dis- play menu.

Image files can be inserted onto the grid as a reference to assist with the placement of nodes. This function can be used to place an architectural drawing or other reference image directly onto the SpaceMap grid. Supported file types are BMP, GIF, ICO, JPEG, JPG, MNG, PBM, PGM, PNG, PPM, TGA, TIF, TIFF, XBM, and XPM.

To insert an image into a SpaceMap:

The image is scaled to match the SpaceMap size, and placed on the grid. To move the image, drag with the Select Objects tool.

Image control

Images can be resized by Shift+dragging. Image placement and properties can be altered after images have been inserted into a space map. To change image properties, right-click the image and select an option from the resulting menu.

Control	Function
Lock Image	Merges the image with the background, removing it from the list of selectable objects.
Unlock Image	Restores the image as a selectable object.
Set Display Prior- ity	A numerical value which instructs the image as to which objects in the SpaceMap to visually occlude.
Duplicate Image	Inserts an identical copy of the selected image onto the SpaceMap.
Delete Image	Removes the selected image from the SpaceMap.

The first step in building the SpaceMap is to add Speaker nodes, Virtual nodes, Derived nodes, and/or Silent nodes.

Speaker nodes and Derived nodes are numbered with the corresponding output channel.

Other operations that can be performed with the Select tool include:

Right-click a node (or set of nodes) to edit it with the following parameters.

Add Trisets to create zones for the SpaceMap buses to move through. buses that are outside of a Triset do not produce any output signal.

Alternatively, three nodes can be selected and combined. Right-click and choose Add Triset. To rename a Triset, right-click the Triset and choose Rename Triset.

CAUTION: Trisets can not overlap one another: signal distribution would be unpredictable within the overlapped areas.

Alternatively, using the Select tool, right-click a Triset and choose Delete Triset. If a node that is part of a Triset is deleted, the Triset itself is deleted as well.

If the Speaker nodes are sending to functioning loudspeakers, the sound pans through the Trisets.

Output signal distribution changes as the bus is moved; the bus is represented as a small hol- low circle. Its label corresponds to the bus label. Level changes can be observed in the Matrix display, and at the top of the SpaceMap window.

Derived nodes and Virtual nodes must be linked to Speaker nodes in order to function.

To create a SpaceMap Trajectory:

CueStation automatically connects the dots. The time interval between dots initially corresponds to the time between clicks (see “Modifying a Trajectory” on page 150).

Trajectories can be re-recorded by clicking Record again and drawing a new path. This clears the trajectory that was previously recorded.

Auto-Cue

To record a trajectory in time with Wild Tracks playback, or other types of automation, use the Auto Cue function:

1. Click the Record button. An Auto Cue checkbox and a Cue text box become visible to the right of the Record button.

2. Click the Auto Cue checkbox to enable Auto Cue.

3. Type a Cue ID in the Cue text box. This cue is recalled when the first trajectory point is reached.

4. Click the map to add a trajectory point. The cue is recalled. Continue placing trajectory points as needed.

5. To stop the trajectory recording, move the mouse outside the SpaceMap grid.

Tip

Cues can be set to recall along existing trajectories by right-clicking a TrajectoryNode and assigning a text command, e.g. Recall Cue 123.

To edit a SpaceMap trajectory:

Multiple Trajectory nodes can be selected using the Shift key or by dragging a selection box around them. To select and edit multiple noncontiguous Trajectory nodes, hold Shift+Option (Mac) or Shift+Alt (Windows).

Any of the following operations can be performed on Trajectory nodes:

SpaceMap trajectories can be tested by playing them:

TIP: Observing the Matrix while the bus is moving (by dragging the test control or by playing a trajectory) helps identify awkward transition zones. To ensure seam-

less panning, check that the Trisets have no gaps, and consider using Silent nodes to create a smooth fade-out zone when moving to areas beyond the loudspeaker output sets. A trajectory that crosses any part of the SpaceMap window that is not inside a Triset results in a complete dropout of the signal. It is a useful practice surrounding the main part of the map with a safety zone of Trisets that includes one or two Silent nodes. This results in the sound fading as the bus moves toward the Silent nodes.

CueStation can auto-draw a trajectory based on a parametric equation. To access this function: