I am recording in a very large room and getting sound reflections off the walls. So I was going to buy acoustic foam for the walls. Before I buy the foam, I wanted to measure the frequency response of the walls because there are different foams that target different frequency ranges. I have set up an audio system in the room to measure the reflections.
What type of waveform should I play to measure the reflections? I was considering the following:
- An impulse. This seems like the obvious choice, however I can't get a very loud impulse noise from my speaker. I am using waveform where the audio level jumps from its lowest point to its highest point and back over a single point.
- A fast sine sweep. I could use a sine sweep that plays very quickly. It would have to play quick enough that it finishes before the reflections return back.
- Pink noise. Because there is randomness in pink noise, I would probably have to do multiple tests and average the results.
- Single frequency sine waves. I could go through the frequency spectrum at 1/3 octaves and make a recording for each frequency. This would be more time consuming.