There is one other thing that the stacking method allows, btw, that cannot be as easily accomplished with a spreadsheet, or some other simple mathematical method. And that is that it allows different response curves to be combined together which do not have the same quantity or configuration of points in their plots.
Why is that important, you might ask?
Well, let's say you want to combine the response curves of several different headphones together, like the ones in the graph in my last post, for example. But the plots you've created for each headphone have different quantities or configurations of points. (Which is something you can easily do in Equalizer APO's configuration Editor, using it's
variable graphic EQ option.) The stacking method above still allows the curves to be added or combined together in the Analysis Panel, regardless of how many points each curve has, or what the exact configuration of the frequency bands is in each curve.
This is a feature that I take advantage of all the time, when creating EQ curves for my headphones, either from scratch, or using various reference curves (including the response curves of my own headphones) in Equalizer APO's Configuration Editor...
Some examples of different "variable" graphic EQs in Equalizer APO's Configuration Editor from my previous EQ projects:
But I hadn't really thought of using an approach like this to compute an
average response curve from multiple response curves before, which is a bit different. It could be a potential time-saver though, because it means that each curve in the stack can have as many, or
as few points as necessary to achieve an accurate plot for that particular speaker, or headphone, etc... Which could also improve the accuracy and precision of the final result.
All of the sound power curves in my earlier example above have the exact same quantity, and configuration of points or frequency bands in their curves. And the only things that differ are the amplitudes or decibel levels of the points (which are displayed in the columns on the righthand side of each plot)...
The curves
had to be plotted this way because I was originally using more of a spreadsheet-like approach to combine them together mathematically, with individual columns for each frequency band.
The stacking approach shown above does not require this though. So each response curve in the stack can have as many or as few points as needed for a precise plot. This potentially makes it much easier to combine the plots of different headphones (or loudspeakers, or EQ curves) together in a single project or graph. Even if the plots have different point configurations.