The quest for the best

[skatz]

OK here's another crack at it. Go to post "InDIYana 2018 dates are official" on this list, and see post 194--there are others but that was the first I came to. This was a speaker actually built by Harry Olson, 15" coax, in a donut shaped enclosure. It sounded remarkably good I thought.

[Dave Bullet]

The 30s were a great decade for innovation: radar, television, tape recording and the helicopter, to name but a few inventions, all came from that period.
Geoff

Necessity is the mother of invention. War is the mother of necessity.

[scholl]

Lots of rich folks but also Hotels and bars used these in public areas too. A nice PA system. Hear the boxing match or regatta at your favorite bar.

[skatz]

One more try.

[skatz]

PE seems to have solved the problem posting photos. This is the Harry Olson enclosure I mentioned in an earlier post, a 15" coaxial in a donut enclosure, which should eliminate most edge refractions.

[craigk]

[dst]

The "Big Brother" speaker, as it has it's eye on you!

[Pete Schumacher]

PE seems to have solved the problem posting photos. This is the Harry Olson enclosure I mentioned in an earlier post, a 15" coaxial in a donut enclosure, which should eliminate most edge refractions.

Edge diffraction is still there. Its just that the baffle step transition is now greatly smoothed. However, because the tweeter is not presented with the same smooth wall transition, there will probably be quite a bit of diffraction ripple in the upper octaves.

[fpitas]

Is that available with maple frosting?

[Wolf]

Can't you see it's a bagel, not a doughtnut!?
How about some cream-cheese?
Wolf

[skatz]

Bagel, schmagel!
Of course there is still diffraction, but ameliorated quite a bit by the enclosure.

Steve

[fpitas]

Bagel, schmagel!
Of course there is still diffraction, but ameliorated quite a bit by the enclosure.

Steve

I doubt the enclosure does much above a few hundred hertz. That's still useful, but not a panacea.

[skatz]

I'm not sure if it was Olson, or one of the other pioneers, but someone published diffraction data on different enclosure shapes. The sphere was the least diffractive; this would approach that.
Harder to see in the photo, but the surface of the 15" cone was studded with pyramidal shaped projections; I'm sure that would mess up the diffraction from the tweeter considerably. I am not sure what the function of those was supposed to be.
Never claimed it to be a panacea, just of historical interest.

Steve

[badman]

That's not a doughnut it's a piece of corn dog.

[skatz]

Each to his own.