[PeteD]

brucek wrote:

REW (of course) generated the signals and measured at 75dBSPL.brucek

I am obviously not asking the question well. For example, is the mic placed in close proximity to a 15" woofer to make the measurements in air? i.e. Is generating the tone in air part of the error involved with measuring this low?

brucek wrote:

You missed my point. I don't dispute the frequency content, only the use of cheap RS meters, Galaxy meters, ECM8000 mics for any frequency less than 10Hz is nuts......
brucek

I see! I was thinking that the Galaxy meters were reproducible even at some of those single digit frequencies. Is the fact that ECM8000 was used and not really accurate that low the problem?

i.e. Can you calibrate a specific lower end microphone with a high end mic (not ECM8000) to measure these low frequencies or do you really need to use a high end mic to measure the frequencies directly to plot response down this low?

Thanks,
Pete