Great Waveguide List

[keyser]

Paul, I sometimes measure horns by letting them face up. Works pretty well!

[ScottG]

Originally Posted by paulspencer

The scale is chosen so that a contour line shows up that corresponds to the beamwidth (-6 dB). If I were to force the PSE-144 sonogram to follow a particular standard, you would not so easily and intuitively see how its dispersion compares to the 80 degree nominal target.

I think it could be worked out with a better use of color (achieving both the dominate beamwidth while still providing considerable detail). I'm not sure if Arta allows this function though, so it would likely have to be corrected in something like photoshop.


I do think it's a good job of measuring (under domestic constraints) - with very good lower freq. measurements for the horn.



Anyway.. the PSE-144 looks like a good candidate for this sort of design solution :

HAIGNER Horn Loudspeakers | Alphahorn

[noah katz]

Scale seems fine to me, it had -6 and -12 dB contour lines.

I also prefer them w/response normalized so as not to muddy the directivity waters.

[Juhazi]

Dear Santa Claus,
I want to see both raw and normalized graphics. If on-axis spl is shown, directivity sonogram can be just the normalized version. I'd like to see both 1/3oct and 1/12 or 1/24 smoothing too because I want to see the forest and trees. Impulse gating must be told too, this is very important specially when measurements are done how most of us are usually doing it, behind closed doors. Sometimes I also want to see unsmoothed response measurements of various angles horizontally and vertically, with various gating - sort of hardcore for the late hours...

I will be a good boy!
Juha

[gainphile]

To keep this list clean and short, I've opened a new thread for the above horn:

www.diyaudio.com/forums/multi-way/254468-pse-144-horn-discussions.html

Please discuss there. Thanks

[gedlee]

Originally Posted by noah katz

Scale seems fine to me, it had -6 and -12 dB contour lines.

I also prefer them w/response normalized so as not to muddy the directivity waters.

A single color for everything above -6 dB is pretty coarse. And as to normalized it makes the results look completely wrong with no way to tell what is really going on unless you post the normalization curve as well and then it is very difficult to adjust what you see when you need to look at two different graphs to tell anything valid. You cannot look at a normalized plot and what the frequency response is at any location - you can tell that at every location if they are not normalized. I'm sorry, but normalizing is completely wrong - it is NOT the way the speaker radiates sound.

And as to the DI being different than an Abbey/Summa, there really isn't any difference (if we consider averages). The PSE-144 is nominally 80 degrees and the Abbey/Summa is 90. The control stability in the Abbey/Summa is much better however.

Paul - did you get a license from Danley to produce these? They clearly violate his patent. He probably does not have an AUS patent, but you could not export them to the US without a license.

[noah katz]

Originally Posted by gedlee

A single color for everything above -6 dB is pretty coarse. And as to normalized it makes the results look completely wrong with no way to tell what is really going on unless you post the normalization curve as well and then it is very difficult to adjust what you see when you need to look at two different graphs to tell anything valid. You cannot look at a normalized plot and what the frequency response is at any location - you can tell that at every location if they are not normalized. I'm sorry, but normalizing is completely wrong - it is NOT the way the speaker radiates sound.

Agreed on one color for a 6 dB range.

When looking at a sonogram I don't want to see the frequency response is at any location; I prefer polars for that.

If normalized you can see directivity characteristics on a soinogram at a glance; otherwise how the heck can you separate the directivity from response variations?

[gainphile]

Further discussions on PSE-144 here. Let's try to keep this list clean

[gedlee]

Originally Posted by noah katz

When looking at a sonogram I don't want to see the frequency response is at any location

That is exactly what I do want to see.

If normalized you can see directivity characteristics on a soinogram at a glance; otherwise how the heck can you separate the directivity from response variations?

I do not want to separate the response from the directivity. They are intimately coupled in the real world and that's the way I want to see it.

[noah katz]

Perhaps that useful to you as a skilled designer, but as an end user I'm interested in the directivity characteristics on their own.

Ah, maybe I see what you're getting at - if the response varies as a direct result of spatial power distribution aka directivity, then you'd want to see that.

My original thought was that I wanted the response normalized to take out the effects of the driver.