A Fourth Look at Graphs
Now that all the measurement groups are defined, you can plot them on a graph. Select the Data View tab at the lower left of the main window. You created several graphs earlier in the tutorial, but these were only for demonstration purposes, so they can be deleted. To delete a graph, select its icon (named e.g. Graph 1, Graph 2 etc.) in the Data View and press the Delete key. Repeat this action for all existing graphs unless you're sure you want to keep them.
Create a new graph, and under Data in the Graph Properties dialog, select Measurement Groups. The four measurement groups you created are shown in the dialog as below.
Check the checkboxes of all four of them and click Apply. Under Format, select General. Change the graph title from SPL vs. Frequency to Combined Response SPL vs. Frequency. Check the Show legend checkbox. Under Format, select Axes and disable autoscaling for the left y axis. Set the lower limit of the left y axis to 50 and its upper limit to 125. Click OK.
You'll notice the trace names are automatically generated, but these names aren't descriptive of their actual meaning. In the Data View, you can expand the tree nodes of each trace to see its constituent parts. Both the names of graphs and their traces can be changed. When you change a trace name, the new name will show up in the graph's legend. When you change a graph name, the new name will show up in the tab of the graph window. Before renaming, the trace display in the Data View looks as below.
You rename graphs and their traces by selecting their associated node in the tree, pressing F2, and entering new text into the edit control that appears. Rename the graph from Graph 1 to Combined Responses. Rename each trace to the name of the measurement group that it displays (that is, [Meas group] Trace 1 will be renamed to MLP and so on for the other traces). When this is done, the Data View will look as below.
The graph legend now shows the new trace names, which are more descriptive of what's being plotted. The tab at the top of the graph window now reads Combined Responses and the legend entries now match the trace names.
Another problem is that the traces are all on top of one another. It would be better to separate them to make them easier to see. To do this, you'll add display offsets to three of the four traces. Right-click the graph and choose Trace Properties. This opens up the Trace Properties dialog as shown below.
The new trace names you chose also show up here. The edit control labeled Magnitude display offset, dB is used to enter the desired offset. For MLP, leave the display offset at 0. Set the Pos 2, Pos 3 and Pos 4 offsets to -15, -30 and -45 dB respectively and click Apply. Before closing this dialog box, notice the Plot live data when optimizing option. When this option is checked and an optimization is running, the trace will be animated, updating continuously with the best solution currently found. It is strongly suggested to leave this option in the default checked state.
After making these changes, the Combined Responses graph should look as below.
Many problems exist in the data of Figure 26, especially in position 3, which has a big peak at about 51 Hz, followed by a suckout at about 62 Hz. Simply applying EQ to make the response flat at the main listening position would still leave many problems at the other positions. This is the kind of problem that MSO's optimization was designed to solve.