Spacemaps

Spacemaps

This page includes definitions and examples of items that are used to create a Spacemap. See Create View for Spacemap creation and editing instructions.

What is a Spacemap?

Spacemap multichannel panning enables the placement and movement of sound through space using a graphic interface. Traditional pan controls for stereo systems are one-dimensional. They shift sound along a line between two points: left and right. A Spacemap, on the other hand, uses a two-dimensional interface that represents either a 2D or 3D space, depending on how they are constructed. A sound is moved with the Spacemap Panner. Each input of a Spacemap System can have one or two Spacemaps assigned to it.

Spacemaps are constructed from two basic elements: Nodes and Trisets. Nodes commonly represent the positions of loudspeakers or groups of loudspeakers, and can be of several types. Trisets link three nodes together, providing the means to distribute signal proportionally among them using an equal-power panning algorithm. An input is represented by the Spacemap Panner. The closer the Panner is to a Speaker Node, the more the input channel signal is sent to the outputs associated with that node. A Trajectory is the path along which the Spacemap Panner travels.

Nodes

Nodes are the points that audio is panned to within a Spacemap. They can represent physical loudspeakers (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). The node types are covered in a section below.

Spacemap Go  – Node Types: Speaker, Virtual, Derived, and Silent

Trisets

Trisets are triangular panning surfaces defined by three nodes. They ensure smooth panning without signal drops, like the 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.

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 Spacemap Panner and each of the three surrounding nodes, rather than the actual physical distance within the grid.

Spacemap Go – One Triset Including Three Speaker Nodes

Trajectories

The path along which a sound moves is called a Trajectory. A Trajectory can be recorded, edited, and reshaped, then assigned to an input channel, played, and modified while it is playing.

Trajectories automate the movement of the Spacemap Panner, which depending on the Spacemap design, creates the illusion of a sound moving, sound fading in and out, and a variety of other effects. The relative position of the Panner within a Triset determines the proportion of signal sent to each of the nodes in the Triset. The actual signal levels can be observed in the Channel View at the top of the display.

Each trajectory is an entirely independent entity, with no absolute relationship to any one Spacemap. One Trajectory can be assigned to each Channel. All or some of the Channel Trajectories can be active at the same time, each being independently started and stopped. From the Mix View, a Trajectory can be started and stopped/reset. From the Channel View, a trajectory can be played back with real-time modifications: rate, rotation, scaling, and position offset. The same Trajectory can be assigned to different Channels and played simultaneously with different modifications for each. See Channel View page for control details.

Spacemap Go – Mix View Channel with Spacemap and Trajectory, Channel View with Trajectory Editing Selected

 

Node Types

Speaker Nodes

Speaker nodes represent the physical outputs of a Spacemap System and are represented in a Spacemap as blue squares. Positions of Speaker Nodes in a Spacemap can represent the loudspeaker layout logically, randomly, or abstractly. Abstract layouts are usually used to facilitate specific panning scenarios that would be difficult or impossible to create with a logical speaker node layout. Each Speaker Node is associated with only one output. However, multiple Speaker Nodes can be associated with the same output. Outputs can be connected to loudspeakers, effects processors, or any other audio device.

Spacemap Go – Speaker Node Arrangement Examples

Each Speaker Node is assigned to a single output. Outputs can be connected to loudspeakers, effects processors, or any other device. Multiple Speaker Nodes can be assigned to the same output.

Spacemap Go – Create View: Speaker Node Parameters

Speaker Nodes Example 1: Circle

The video below illustrates 12 speakers nodes in a circle and the corresponding loudspeaker output. The Speakers Nodes are placed in the Spacemap in their real locations.

 

 

Speaker Nodes Example 2: Circle Shuffle

This video illustrates 12 speakers in a circle. The outputs are not in a sequential order around the circle. The trajectory path pans the sound across the circle rather than sequentially around the circle, creating a shuffle movement of the sound source. A star-shaped trajectory could be used to create the same pattern.

 

Virtual Nodes

Virtual Nodes simulate a physical output for panning purposes and can be used in conjunction with Silent Nodes. Virtual Nodes are linked to Speaker Nodes and/or Silent Nodes. The links are indicated graphically by a translucent line, wider at the Virtual Node, narrower at the linked Speaker Node. When the Spacemap Panner is moved to a Virtual Node, the input signal is equally distributed to the linked Speaker Nodes by default. Each linked Speaker Node has a Link Weight that is adjustable (0-100%), see below.

Spacemap Go – Create View, Four Speaker Nodes, One Virtual Node, Output 1 Link Weight

Virtual Nodes can also be added to complete a Triset, while not being linked to an output. Below, the left Triset uses an un-linked Virtual Node. When the Spacemap Panner moves near this node, the level for Outputs 1 and 2 approaches -inf. dB. The right Triset uses a linked Virtual Node. When the Spacemap Panner moves closer to the assigned Virtual Node, the two outputs levels are -3 dB.

Spacemap Go, Spacemap Test Mode – Upper Virtual Node Un-Assigned, Lower Virtual Node Assigned to Outputs

Virtual Nodes can be used in a Triset with one or two Silent Nodes. Adjust the Link Weights of the Virtual Node to alter the panning results.

Spacemap Go, Test Mode and Create View – Virtual and Silent Nodes, Adjust Link Weights for Various Panning Behaviors

 

Virtual Node Example 1: Below, the Virtual Node (center) is linked to the four Speaker Nodes (corners). As the Spacemap Panner is moved closer to the Virtual Node, the signal is equally distributed among linked speaker nodes. A trajectory traveling around the perimeter of this Spacemap pans from one speaker node to the next. A trajectory that moves toward the Virtual Node (center) causes the signal to spread out to all four Speaker Nodes gradually. This proportional distribution method creates a convincing phantom image throughout the panning area.

Spacemap Go – Test Spacemap Mode: Virtual Node Center, Speaker Nodes Corners, Spacemap Panner at Center and Edge

Virtual Node Example 2: 3D Movement If movement of a sound from lateral loudspeaker positions to overhead positions is desired, use abstract placement of the speaker nodes and add virtual nodes to link to them. Trisets are built including the Virtual Nodes. The Trajectory below pans between the Virtual Nodes, enabling vertical sound movement, simplifying operation.

 

Silent Nodes

Silent Nodes are included in a Triset, just like a Speaker Node, but they are not associated with an output. When the Spacemap Panner is moved closer to a Silent Node, all output levels are reduced. When the Spacemap Panner is on a Silent Node, all output levels are reduced to -infinity dB. This is an easy way to create fade-in and fade-out effects.

When the Spacemap Panner or a Trajectory is not on a Triset of Speaker Nodes, the outputs will suddenly drop to -infinity dB. To avoid this, add Silent nodes at the extents of a Spacemap and build Trisets that include them. The level is reduced when the Spacemap Panner is not within a Speaker Triset instead of jumping to -infinity dB.

Below, four Silent nodes are added to the corners of the Spacemap and Trisets including them are built. By adding these Silent Nodes, the Spacemap Panner can be moved to any point in the Spacemap and there will not be a sudden loss of signal.

Silent Node Example 1: Fade Out

 

Derived Nodes

Derived Nodes link to one or more Speaker Nodes and receive the sum of the signals from the linked Speaker nodes. They are represented as hexagons in a Spacemap. Dashed lines indicate the Speaker Nodes they are linked to.

Derived Nodes are used as a method to send input signal to additional outputs, relative to the linked Speaker Nodes. They are commonly used for subwoofer sends, fill mixes, sends to balconies, and other cases where a secondary mix-down of a multichannel mix is required.

When a Derived Node is added, it is assigned to the next available output, which can be changed, see below. Each link level of the associated Speaker nodes can be adjusted, see below.

Spacemap Go – Create View: Derived Node Options and Speaker Node Link Level Adjustment

In the example below, the Derived Node output is connected to a single subwoofer. It is linked to the nodes sending to the mid/high loudspeakers connected to outputs 1 and 2. The subwoofer receives a constant signal as the Spacemap Panner is panned between the Speaker Nodes. When the Panner is centered between outputs 1 and 2, they each receive -3 dB level, while the Derived Node (output 5) receives 0 dB. When the Panner is moved to the right, the levels change for outputs 1 and 2, while the level of output 5 remains unchanged.

Spacemap Go – Test Spacemap Mode: Spacemap Panner Centered, Spacemap Panner to Right, Derived Node Level Remains the Same

Two Spacemaps Per Output

Each input channel can have two Spacemaps assigned. The level sent to each is adjusted with a slider, changing the percentage of the input signal sent to each Spacemap. The Spacemap with more than 50% selected is displayed. They both remain active unless 0% is selected for either Spacemap. This function adds another dimension of panning to Spacemap Systems. Below, the percentage is set with the horizontal blue/orange slider.

Spacemap Go – Select Spacemaps, Mix View of Channel, Channel View of Spacemap

Spacemap Examples

3D Spacemaps

Control of a sound source movement in 3 dimensions is accomplished using two different methods:

Method 1: Create a Spacemap with nodes representing surround/lateral loudspeaker positions around the edge of a Spacemap and overhead loudspeaker locations near the center of the Spacemap. Move the Spacemap Panner around the edges for lateral panning and towards the middle to move the sound vertically.

Example: 1o surround and 4 overhead loudspeakers represented logically in the Spacemap. The video below pans the input around the lateral positions at the edge of the Spacemap, then overhead by moving the Spacemap Panner towards the middle four nodes.

Method 2: Each channel in Spacemap Go can have two Spacemaps assigned. A percentage of the input signal can be sent to each Spacemap (0-100%), a cross-fade between the two. For example, a Spacemap could represent the lateral loudspeaker locations and another Spacemap could represent the ceiling loudspeaker locations.

Example: the first Spacemap has 10 lateral speaker nodes (outputs assigned from 1 to 10) and the second Spacemap has the 4 overhead speaker nodes (outputs assigned from 11 to 14). The video illustrates how the Spacemap cross-fade function changes the outputs combining these two Spacemaps. Observe the output levels changing at the top of the display.

 

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