Thanks for your expert replies. This is a graph of panels still under development. I was wondering if they would be usefull since they are only 1/2" thick.
I don't know if this is material that has been forgotten, or not, so I'll include it.
The X axis is horizontal, the Y axis is vertical and the Z axis is as if you were looking along it. Where they all cross is the zero point. That defines three dimensional space and it works well for these graphs because they're dealing with three components. This is sometimes referred to as a TEF, or Time/Energy/Frequency plot, or graph.
If you remember Math class and working with graphs, using coordinates (X & Y) in two dimensional & (X,Y,Z) in 3 dimensional, the numbers that correspond to the X coordinate to the right of the Y axis have a positive value and the Y coordinates in the upper two quadrants have a positive value. An X coordinate to the left of the zero or a Y coordinate below the Zero point on the X axis, has a negative value. On the Z axis, behind the zero the coordinate has a negative value and in front of, or toward the person reading the graph, the value for the Z coordinate is positive.
This was a hard one for those who had difficulty understanding absolute values.
So, if you look at the "waterfall", the lowest frequency is at the left and the highest is at the right. The amplitude, volume or intensity (these are often interchanged) can't be a negative value, so it starts at Zero and goes up from there (it can't be quieter than absolutely silent). The signal level varies with frequency, especially when speakers or room treatments are being measured. Time will also begin at the Zero and advance toward the reader.
