Wideband globes

[TNT]

Thanks! I'll check that out for sure!

Have you heard:

4 Balladen * Barcarolle * Fantasie | Discogs

?

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[scottjoplin]

I have it Excellent

 

[TNT]

So in order to play scottjoplins suggestion via Tidal I had to hook my laptop up via opto in - good playing!!! - I took the chance for a few sweeps. This is on axis, 30 cm distance - only globes inc filters 12 db/oct at 300 Hz.

Here I see also the difference when tuning for linear (however tilting!) FR and close sweep measurement.... Interesting.. I need to EQ this linear and see how that works out.

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[xrk971]

I’m going to give this a try with an IKEA 12in bamboo Blanda bowl. Debating what driver to use. Scan Speak 10F/8424 has a round bezel and would be the epitome of a smooth ripple free driver in a diffraction free speaker spherical cabinet. Would it be enough just to have the sphere on the front half only? A dagger would protrude out the open back. I don’t really care about diffraction on the back 180deg.

 

[TNT]

In a very successful implementation and environment I'm not so sure that an open back is good. I bet it has some impact

I was not surprised about the 300-1k distorsion behaviour - I think I hear a bit of muddiness maybe and I dont think this small horn can do a lot of 'reflection digestion' below 1k really. I would have been nice to see that like the rest of the upper region. Maybe its the "horn" - I need to do a dagger. I also own 10f/ and I wonder if you think these would work better the the Faital?

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[KCHANG]

Would it be enough just to have the sphere on the front half only? A dagger would protrude out the open back. I don’t really care about diffraction on the back 180deg.

Dr. Olsen's study shows that a hemisphere is not without ripples in the response (albeit better than a cylinder).

So, better buy four of those Blanda bowls to make two spheres. A dagger protruding from the back of a sphere should make an interesting design.

Kurt

 

[TNT]

The figure surely look like a 1/2 sphere

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[wesayso]

It is, here's the complete list from Olsen (thanks to P10)

 

[scottjoplin]

Odd that it's worse than the last one?

 

[wesayso]

I guess if you'd fit a cylinder shape on the back of the bowl it would be better.
(but the edge of that cylinder would still be equal distance, the sphere has no edges , the rectangle has different distances to the speaker)

 

[TNT]

I need to close my globes ;-) They are like 75% sphere.

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[scottjoplin]

That's too severe

 

[xrk971]

I am surprised a hemisphere is so bad - but I guess it has equidistant sharp edge with a round over.

Maybe a simple foam core long tail cone to make it look like a tear drop can work?

A sphere is just a smooth hypercube/Tesseract?

Hypercube Loudspeakers

There is some sort of resonance at 2k:

This used the interior chamber of the hypercube and not a Dagger rear chamber. Dagger would probably help.

 

[TNT]

I wonder if the Olson bodies are hollow or solid...

I'm contemplating something like:

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[KCHANG]

That looks a lot like the enclosure for the mid-range driver in B&W 801 Nautilus. They used that shape mainly for guiding the internal reflections, however, instead of controlling the external diffractions, according to their marketing literature I read a long time ago.

Kurt