When I was doing the sweeps, I started out at 20 Hz, then tried 10 Hz. The graph stayed pretty flat, and my curiosity was killing me, so I went down in one hertz increments until I got to 5 Hz and stopped there. I could feel when the vibration started and a little higher in frequency the entire room (about 6000 cubic feet) was literally shaking. I couldn't do anything about the empty space on the graph. When I did the measurement capture in the REW software, what you see is exactly how the graph came out. I used the software feature to show the three measurements on the same graph. Next time I can have them on separate graphs. I also need to learn more about formatting the graphs with the REW software.
I have three microphones, the Behringer (used for the graphs here), AudioControl and the one that comes with the MEN220. I will try them all. With regard to comb filtering, I set the graphs at 1/12 octave smoothing because there are twelve notes in the chromatic scale and I felt a room frequency response with a resolution of one note would be meaningful in the realm of listening to music.
The low end stayed very smooth, even without any smoothing it looked just like you see the graph. The comb filtering was more apparent at the very high end. I will be running more tests, but the next week will be very busy.
I have three microphones, the Behringer (used for the graphs here), AudioControl and the one that comes with the MEN220. I will try them all. With regard to comb filtering, I set the graphs at 1/12 octave smoothing because there are twelve notes in the chromatic scale and I felt a room frequency response with a resolution of one note would be meaningful in the realm of listening to music.
The low end stayed very smooth, even without any smoothing it looked just like you see the graph. The comb filtering was more apparent at the very high end. I will be running more tests, but the next week will be very busy.