Setting up the Nathan 10

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#102
Not so - those are beamwidth patterns not polar maps or polar responses like I do. Beamwidths can be very misleading.

Everybody who looks at polar responses agrees that the polar map is the right thing to do, although I do mine in far greater detail than what I see anywhere else. I just don;t see the point of not showing the details - well maybe there is🙂
 
#105
Earl:

What do you mean by 'just physics' when you have shown a normal spread in your data for horizontal dispersion over 45 degrees, when Markus shows them congested?. Either his speaker has the same mouth diffraction as your measured prototype or not. If it is not reflection related, and Markus data are reflection free for those angles, then either he has a different speaker, or you have done something differently for collecting your original data. Please elaborate.

Markus:

The vertical data is uninspiring. I hope that they don't contribute much in room sound. Markus, can you perceive them as hollow sounding when doing the archetypal sit down - stand up test?
 
#106
Show me a loudspeaker with better polars. Those are actually quite good vertical (comparitively speaking) and excellent horizontal. As I have said over and over again, the horizontal is what counts.

I can't explain the differences in our measurements, but yes, I notice that his bunch up off axis and mine don't. I don't know why that is. Different axis of rotation, different distances - lots and lots of variables. Where it counts our data matches pretty good.

If you do a lot of measurements you will know that its hard to measure the same speaker in the same setting twice and get the same results. Matching someone else using a completely different speaker in a completely different setting, using completly different equipment - thats virtually impossible.
 
#107
Thank you, Markus. It's the vertical nulls at crossover I mostly wanted to see, and they're clearly major. From what I understand, the issue, if it may be said there is one, is the C/C distance between the drivers, a problem with practical application of axisymmetric waveguide designs.

And Salas has also observed the "bunching" of off-axis attenuation in your horizontals as opposed to Earl's measurements. Something's up there....
 
#109
Post the verticals for Nathan 10, Earl. This is the first you've told us they are "not as good." Users can decide if that is important to them or not.... :yes:

Markus: Earl detailed his "Room diagonal" measurement technique in another thread here. Link us when you find it, please.
 
#110
gedlee said:
Show me a loudspeaker with better polars. Those are actually quite good vertical (comparitively speaking) and excellent horizontal. As I have said over and over again, the horizontal is what counts.

I can't explain the differences in our measurements, but yes, I notice that his bunch up off axis and mine don't. I don't know why that is. Different axis of rotation, different distances - lots and lots of variables. Where it counts our data matches pretty good.

If you do a lot of measurements you will know that its hard to measure the same speaker in the same setting twice and get the same results. Matching someone else using a completely different speaker in a completely different setting, using completly different equipment - thats virtually impossible.
Click to expand...

Earl, relax. I am not criticizing your verticals. I know that these are not coaxial speakers. I just ask Markus if he can feel them at all in the room sound.
As for the wide angle squadron mismatch between your and his data, now you speak wisely. I just did not think that just diffraction physics could really explain it in a more or less identical WG mouth, and cabinet roundover. Differences in practices and places and gear, yes, they well do. We don't know the sensitivity of that mic, or the total system's SNR, including Donald Trump's helicopter😀. I was the first to positively comment on the consistency of the meaningful 50 deg lot, a few posts before.
For me the meaningful data is there too, and that is why I did not rise an eyebrow originally. Not even for the midrange hump that it is proximity related IMO.
 
#111
markus76 said:
Earl, how is your setup? You measure within a room too? How do you minimize room artefacts with a mic distance of 2m?

Best, Markus
Click to expand...


I have a big room. 12 ft ceiling is the major thing since this distance is virtually always the big problem. I wrote all my own software so I trust it and, as I said, I've been doing this like this for more than 5 years now in several different locations. One was the factory in Thailand which had a huge room. The results all correlated very well (for acoustic measurements).

There are going to be vertical nulls when ever you have non-coincident drivers. They are arrange so that they minimize the floor and ceiling bounce.

The falloff that you show beyond 45 degrees is not really even plausible, but I never thought it worth mentioning as its down thats all that really matters.
 
#113
No Earl. That is not criticism. I would have said ''unexpectedly bad for such a speaker format''. Uninspiring verticals goes with the territory. I want to know how much power response audible they are, given your projection arrangement with your WG. If it was in a club, we would have optimally aimed the WG by angle from truss mount. But in home, on a stand, there must be difference when standing up. Markus will enlighten us subjective wise.
 
#114
gedlee said:
There are going to be vertical nulls when ever you have non-coincident drivers. They are arrange so that they minimize the floor and ceiling bounce.
Click to expand...

Yes, at +/- 20°, perhaps, defeating any supposed advantage of the apparent 70° axisymmetry of this design. Further, the nulls are only effective in the crossover region; if the purpose is to minimize floor and ceiling bounce, the directivity of the waveguide itself must accomplish that throughout the balance of its response spectrum.

However, if Markus's measrements are correct, the nulls are prominent at +/- 5° here, each generating a 6 - 10 dB, octave-wide hole in the response at crossover; the listener must be precisely on-axis vertically to avoid them.

Again, post your verticals for Nathan 10, so that we may know and compare your design intent with Markus's actual result.... :yes:
 
#116
Did a test with a sinus at 1133 Hz. There are nulls perceivable when moving the head vertically. But having all the reflections it's hard to say what is caused by the speaker and what by interfering reflections.
Again I'm very happy with the modal behavior of the room. There's a problem at around 80 Hz and 50 Hz but it should be in the range +/- 5 dB or even smaller. In my old room I had modes with +/- 15 dB!

Best, Markus
 
#118
I'd say the vertical response is about the same across the systems. Because of the crossover topology there has to be two nulls, one up one down, where they occur is C-C spacing dependent, but not if they occur or how many. I don't obses over the vertical response because I do whatever I can to get rid of these reflections. But I DON'T absorb the side wall energy so the horizontal response is critically important. And with a 45 degree toe in the horizontal response become even more critical.
 
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