Recent content by anyfoo

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    Null Pointer Exception when trying to import sweeps

    Thanks, fixed there indeed!
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    Null Pointer Exception when trying to import sweeps

    I can attach the files if necessary.
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    Null Pointer Exception when trying to import sweeps

    I recorded some sweep measurements using TwistedWave on my Mac. If I try to import them in REW V5.20.13, everything goes fine until "Calculating Frequency Response", where the following NPE appears: REW V5.20.13 running Azul Systems, Inc. JRE 1.8.0_345 64-bit on OS X 13.3.1 Locale: language en...
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    distortions are images in time before the impulse response

    Isn't the "distortion" here just anything non-linear done to the signal in general, which can really be anything? I guess we make some (probably reasonable) assumptions about what the distortion is, then? Maybe it's physically impossible for lower frequencies to appear in "real", analogue...
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    zeroes in unit circle, minimum phase

    Ah, yeah, my bad. It's a sampled spectrum, dependent on how long the FFT is. I guess artisanal and hand-crafted is still the way to go. 8)
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    distortions are images in time before the impulse response

    I think I found the answer here: https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.118.7473 Specifically on page 19: This is very enlightening and makes intuitive sense. I guess an open question I still have is what happens with distortion products that are lower than the fundamental...
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    distortions are images in time before the impulse response

    This looks to be just about sample theory in general, which I'm hopefully already familiar with. I'm specifically looking for literature (or just an explanation) on how non-linearities end up as earlier images when computing the impulse response from a log sweep.
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    distortions are images in time before the impulse response

    I would like to understand how distortion images end up in time before the impulse in the calculated impulse response. I'm interested in the actual math. A quick Google search turns up nothing immediately relevant (though Google has been deteriorating for years, especially when searching for...
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    zeroes in unit circle, minimum phase

    Hello, When I look at the "System Response" of a measurement I took inside my car, it consists almost entirely of zeroes inside the unit circle. Doesn't this mean that the system is, by definition, "mostly" minimum phase[1], and so reversible? (Cancel each zero with a pole inside the unit...
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    phase unwrap display unwieldy?

    Ah, didn't realize the cursor affects the unwrapping. Thanks.
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    phase unwrap display unwieldy?

    I just had another thought. Maybe it would be worth having a "partial unwrap", i.e. unwrap the pase n times, before allowing it to wrap again? The wrapped phase is a bit hard to look at since it tends to wrap very quickly with steep slopes. Just unwrapping a few times and then allowing to wrap...
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    phase unwrap display unwieldy?

    Hello. Whenever I try to unwrap the phase, the phase display gets rather unwieldy. There are sometimes phases in excess of thousands of degrees (which I don't think is too unexpected, at least in non-minimum phase systems), but I have a hard time fitting all of the graph in the window, using...
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