Window...

[TNT]

Hi!

The naming in the IR window - can it be improved?

It now says "Left Window" and the unit is ms.

Wouldn't "Window start at:" and "Window stop at:"

be a more clear and logical naming?

Or have I misunderstood the whole ting? :-)

Is there two windows - one to the left and one to the right and one sets the length of these windows in ms? :-D

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[John Mulcahy]

Is there two windows - one to the left and one to the right and one sets the length of these windows in ms?

Yes, there are two half-windows. The pre and post ref windows can be different types and different lengths.

 

[TNT]

And the two windows join at "Windows Ref time"?

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[John Mulcahy]

Yes.

 

[TNT]

Never to be separated?

 

[John Mulcahy]

I don't know how one might use a window with a gap in the middle.

 

[TNT]

OK - so why two windows...

Whats the strength of a two half windows with lengths paradigm vs. one window with a start and stop time?

I'm just really curious! :-)

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[John Mulcahy]

When analysing the frequency content of an impulse response there is little of interest before the peak, a short window is appropriate there. Post peak the window length will determine the LF limit of the frequency response and the window should be unity over regions where reflections are of interest, a window that tapers from the start would attenuate the reflections and conceal their full effect on the response.

A similar situation arises for the windows used to generate waterfalls, but there the width and shaper of the left window has a strong influence on the appearance of the waterfall (aka the 'rise time' used).

 

[TNT]

Thanks!

But it was not so much what a window is than why a software model of 2 half windows was chosen?

I can really see why you wouldn't want or have time to discuss this at all so...

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[John Mulcahy]

Because the two half windows typically have different shapes, different durations and different effects on the result. How else should that be described?

 

[TNT]

Aha - possibility for different shapes - OK. That makes it very flexible.

One thing that would have helped me initially to understand better would have been:

Right win. duration (ms):

As of now there are 3 items, all with ms as unit but two are durations and one is an absolute time... I managed to not catch that...

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[John Mulcahy]

They are labelled differently in the 5.20.14 builds.

 

[TNT]

Like it - great!!

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