Up and running very cool!!!
Quote:
Originally Posted by Zilch
Interestingly, the basic results are the same above 1 kHz for each setup. Your space must be nicely damped, as reflections aren't majorly apparent.
Windowing cleans it up below that, mostly, but 7.7ms window renders everything below 150 Hz invalid, no?
Gotta use different methodology to get useful results below that, anyway.
D'Appolito says measure on tweeter axis. It's now clear why.
Big differences in the 800 Hz region between your two test heights. I'm guessing you're crossed over somewhere near there?
Zilch,
Rob is using 1/3 octave smoothing. That removes most of the detail and some of the reflection information.
His time window is 4.5 and 4.7ms. If you read the Stereophile articles that I mentioned in an earlier post and Rob tracked down:
http://stereophile.com/features/105kh/
http://stereophile.com/features/405time/
They explain that it isn't all that simple to determine the accuracy of the lower frequencies from a time windowed measurement.
Unless Rob used a larger room than the 7' plus ceiling height of his listening room, he should be windowing closer to 3ms anyway, but that aside... I would suggest that these are accurate to about 1KHz... below that we are seeing a lot of room modes and early reflections.
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