[aktiondan]

I've been curious about doing the same type of measurement, maybe a future revision of REW could include a frequency adjust for the start point as well? In addition to other target filter functions besides ones for just subwoofers. I'd like to set the target filter for high-pass at 3kHz and then measure a tweeter w/ and w/o a crossover. What I have done before is just thrown in a single large cap in series with the tweeter just to block out most of the really low frequencies. A 1st order x-over will have a very small negative impact on the performance/measurement of your tweeter and yet still keep it from getting damaged by the low-frequency stuff (as long as you still keep the levels low, and measure in the near-field, 1/2" or so away from the tweeter). A 20uF cap will put you 3dB down at 1kHz, assuming your tweeter has a nominal impedance of 8 ohms, which should be enough to not damage it during a couple of quick sweeps starting at 0hz. If that doesn't seem like enough attenuation, then a 13.3uF cap would put you 3dB down right at 1.5kHz and then it's 6dB/octave from there. However I agree it would be nice to have an adjustable start frequency as well in REW for doing these kinds of tests.