SPL Rendering

SPL Mapping can be enabled and disabled from the SPL switch in the 3D View panel’s header. It is always off when a project is first loaded. The 3D View displays multi-layer mapping, meaning all frequency bands are calculated at once. Selecting a different bandwidth to view will not require recalculation.

To change the mapped stimulus, bandwidth and weighting, use the drop-down boxes which appear next to the SPL switch while it is on. By default, Pink Noise is shown as a Broadband, A-weighted map. The stimulus and its level are saved with the project and stay in sync across every tab and window - change the stimulus in one view and all views follow. The band and weighting belong to each 3D View, so different 3D Views can show different bands. Choose Tonal in the band dropdown to switch from the SPL heat map to Tonal Mapping, which shows how consistent the tonal balance is across the audience. To change the Colour Map and the default scale behaviour, open the Application Settings.

The mapped level is determined by the stimulus input level, set in the level field next to the stimulus dropdown. By default this is the Pink Noise stimulus at -8 dBu; click Set Max to map the absolute maximum sound pressure attainable without compromising overall dynamics (i.e. pushing any loudspeaker into its limiter). The resulting headroom is shown in the Maximum SPL / Headroom Panel. For more information about maximum SPL calculation, please refer to Maximum SPL. Shown levels are RMS levels by default. This can be changed in the Preferences.

Reading the Map

The SPL legend in the bottom-right of the 3D View is interactive: double-click it to pin the top of the colour scale so it stops following the data peak, and right-click it to type an exact top level. The Feather button in the 3D view toolbar fades the map where it falls outside the loudspeakers’ coverage, and Cutting Planes can slice the venue to inspect a single zone. Cutting planes apply to every 3D View and are saved with the project. With the heat map switched off, Aim Discs show each cabinet’s aim point on the audience, coloured on the same scale as the map. Throw Lines can be shown with the map on or off. To see the coverage of a single array in its vertical plane, switch on the Map in the Sideview. For point measurements within the map, use the Inspect tool; for a numerical summary of coverage evenness, open the Coverage Panel.

A highly complex acoustical model is utilised for pressure mapping. Its details can be found in the Background to the Application section.