Overlays Window

The overlays window shows plots for all the currently loaded measurements. It is shown by pressing the Overlays button in the toolbar of the main REW window.

The overlay plots are selected via the buttons at the top of the graph area.

The various graph types are:

SPL

All the measurement SPL traces

Predicted SPL

The predicted SPL for each measurement after applying any EQ filters that have been defined for the measurement in the EQ Window.

Phase

All the measurement phase traces

Predicted Phase

The predicted phase for each measurement after applying any EQ filters that have been defined for the measurement in the EQ Window

Distortion

Distortion traces for each measurement, showing the distortion measure selected in the graph controls, which can be IMD, TD+N, THD, THD+N, N, any available harmonic up to the 10th or the fundamental. If a mix of stepped level and other measurements are loaded either the stepped level or the others will be selectable for the overlay. The easiest method is to right click on the graph legend and clear the selections, then select one of the measurements of the type you want to overlay. Only other measurements of that type will then be enabled for selection. Clearing all the selections will mean all measurements become enabled for selection.

Impulse

All the measurement impulse responses

ETC

All the measurement impulse response envelope traces

Step

All the measurement step responses

GD

All the measurement group delay traces

RT60

All the measurement RT60 traces

Clarity

All the measurement clarity/definition traces

Separate Traces

The basic controls for the overlay graphs are described in the main Graph Panel help, but the Overlays window has one additional button:

The Separate Traces button to the right of the graph selector offsets each trace downwards from the preceding trace to make it easier to distinguish individual features when the traces are at similar levels. When the button has been pressed a slider next to it allows the amount of separation to be adjusted.

Graph Controls

The SPL graph has controls to apply smoothing to all the currently selected traces, a control to offset any of the traces and a box to select whether data points should be plotted. The trace offset moves the graph position, but does not alter the data so the legend values do not change. If the Add offset to data button is pressed the current offset value is transferred to the measurement data and the legend readings will update accordingly. If Show points when zoomed in is selected the individual points that make up the measured phase responses are shown on the graph when the zoom level is high enough for them to be distinguished (which may only be over part of the plot).

The Trace options button brings up a dialog that allows the line type of the graph traces to be changed.

The Predicted SPL, Phase, Predicted Phase and Group Delay overlays also have a smoothing control. The Phase and Predicted Phase overlays have additional controls to wrap or unwrap the currently selected phase traces. The Phase, Impulse, Step and Group Delay overlays have a control to show data points when zoomed in. All have the trace options control.

Legend area

Right clicking in the legend area of an overlay graph brings up a small menu that allows all traces to be selected, all selections to be cleared or the selections to be toggled. There are also menus to select or clear traces for measurements that have been loaded from a particular file.

Hovering the cursor over the name of a measurement in the legend panel will bring up a tool tip showing the measurement notes.