Did you know you can show all the graphs together on one screen if you save the mdat files from each measurement and then open them together?
Yes, but it just becomes a mess where you can only really see max and min at a given frequency. I seperated them out so the variation at each point could be seen easier.
Thank you for sharing, but just an FYI REW has a "separate traces" feature that allows you to clearly display multiple traces at once without having to manually shift their SPL. See:
https://www.roomeqwizard.com/help/help_en-GB/html/overlays.html > Separate Traces
Anyway, on one hand, as others have mentioned, this is why averaging is so important
On the other hand, I agree it's important not to obsess too much over in-room measurements.
This also brings up a common misunderstanding about the "predicted in-room response," curve (and by extension, early reflections curve) by the way. People see the PIR and assume it'll match a simple listening position measurement, or even a simple MMM or average at the listening seat. But the PIR as tested in at least Olive, 2004 (Part 2) is quite specific about how it was measured:
"A diffuse-field microphone was positioned at the listener's chair, at average ear height, 3m away from the loudspeaker. The loudspeaker was placed 1.2m from the rear wall, slightly off-center from the side walls of the room. A total of 9 measurements were taken at 0, +/- 10, +/- 20, +/- 30 degrees horizontal, and +/- 10 vertical."
In other words, the PIR basically reflects the listening window of the speaker at 3 meters away, quite a distance away. Note that's also a singular speaker, not a stereo pair.
That's actually quite a large area and I 'd be surprised if most people are doing MMM or averaging quite that large when they measure their PIR. I also wonder what the effect is of having the speaker be "slightly off center" as opposed to closer to the sidewall as it would be in a standard setup.