Different settings produce different looking Impulse Responses

[AustinJerry]

What settings would cause these two Impulse Response measurements to look different? The first one has jagged lines, the second one doesn't.

 

[John Mulcahy]

That's noise. Have you turned off antialiasing in the View preferences, by the way?

 

[AustinJerry]

The impulse showing noise belongs to another user. I'll pass on your comment to see what he says.

In my preferences, I have "Use Anti-aliasing for traces" checked. I can see the difference when the setting is toggled off and on with my impulse response measurements, but I never see noise as bad as the example I posted earlier. Is noise like that an indication of something wrong with the other user's setup?

 

[John Mulcahy]

Perhaps an issue with gain settings along the mic path, assuming it wasn't just measured in a very noisy environment.

 

[Sonnie Parker]

Hey John... I only see it when I use full bandwidth measurements of 0-22kHz. If I only measure 0-400Hz, I don't see the noise.

 

[Sonnie Parker]

Checked.. but still getting noise on full range measurements with timing.

 

[John Mulcahy]

If you are measuring a subwoofer you don't need to make a full range measurement.

 

[Breeman]

My subwoofer measurement looks fine with the 5-20kHz setting. Just wiggles in the first "cycle" of the impulse response which I can't explain.

 

[Sonnie Parker]

If you are measuring a subwoofer you don't need to make a full range measurement.

Even if using the acoustic timing reference?

 

[John Mulcahy]

Yes

 

[Avsaddiction]

Hi,
I see your impulse graph has the peak in the negative (-100%) like some of mine.
Does this mean that somehow the signal polarity the speaker receives is reversed, even though the wiring checks OK?