O.T. ID this whopper

[GM]

Mostly all I get are kids selling junk for their schools. As if I don't pay enough school taxes already! With the illegal invasion, it's considerably more than all my other taxes combined.

I thoroughly enjoyed listening to a transplanted West Coast born n' bred Mexican/American rail against how illegals were negatively affecting his pay/job security along with property values/insurance/maintenance in his neighborhood. He wants the Fed/State gov'ts. to cut off all financial, medical, etc., aid and run them back over the border as much as I do. He was particularly narrow minded about how to deal with the increasing teen gang property destruction/violence.

GM

[wws944]

Thank you GM for posting those scans. Very interesting! I can't help but wonder how the off-axis response held up at 10 khz though.

The wikipedia web page on Bozak is unusually extensive. I think their comments about how many Bozak-designed McIntosh speakers that were sold directly contradicts what Roger Russell says on his pages. (Wikipedia claims 'many', RR claims '5 or so'.)

It is also interesting to me that he varied the cone thickness from center to edge. Seems he used the same concepts much later, through the 1960s at least. How would would that compare to the Altec bi-flex approach? How smooth is the transition between halves of the cone in the 'crossover range' in the Altecs?

[bfish]

Re the directional thing, I think all cones are stuck with the same source size/wavelength/directivity physics.

Edit;
There I go thinking conventionally again...the dust cap was a 6" dome on this honker...

Yeah, the progressive density cone was a neat trick. Unlike most mfrs, it appears Bozak made many of his own cones in-house, and the progressives were a blend of lambs wool and shredded paper.

...How smooth is the transition between halves of the cone in the 'crossover range' in the Altecs?

Badmaieff's '58 BiFlex patent describes the coupling transition;

SOUND-REPRODUCING DEVICE - Google Patents

[bfish]

Well, I've been searching for pictures of Rudy's monsters as they were implemented at the 1939 Worlds Fair. From various clues in the references, there were 8, each in a 14' horn, and located near the Lagoon of Nations. This led to an article in the Aug '39 Pop Sci describing the Fountain of Flame at the Lagoon. On p48, a layout drawing of the Fountain shows them housed in opposing pairs in the 4 round, low "huts" on the Fountain island;

Popular Science - Google Book Search

...one of which is shown in this photo;



(is that dark spot in the mouth a HF horn?)

Piecing together other bits from various sources, it appears that aside from some recorded sound effects, the music they played came from a 40+ piece orchestra which was housed in a remote building. Dual mics were used for independant channels, to give a stereo output (2 horn huts faced one side of the lagoon, 2 more on the other side.

Some references allude that much of the Fairgrounds was scrapped for the war effort that soon followed. Given the need for steel and copper, and the likely deterioration of paper cones in the damp environment, the assumption they were scrapped is a likely one.

Another reference, from a later-day Bozak tech, documented that the one that had been gathering dust at the factory eventually got thrown away. This may have come as a great disappointment for PW Klipsch, who had repeatedly asked for the unit for his personal collection.

[GM]

You've dug up the rest of all I've ever seen on them and WRT a possible tweeter, I have an old/faded scan of a 1941 RCA architectural and engineering specification manual for all things sound recording/reproduction that specs a nominally flat 75-7k cps (Hz) as the norm for vocal and orchestral PA apps (as opposed to the 50-11k for 'true' reproduction in cinema/HIFI apps) which RB apparently used as a guideline for the driver/horn design, so I'm guessing no super tweeter was used, especially since it would have required a visibly big one to keep up with the big horn, i.e. its mouth area would have to have been at least as large as the main horn's throat area, ergo would have been fairly long even if multiple large format drivers were used in a truncated throat.

WRT beaming, obviously, with no polar response plots we can only speculate, but with such a large diaphragm its HF response could conceivably be launching off it out near its surround for a wide enough HF 'sweet spot' if its material had the right TL velocity factor for the BW, though it seems reasonable to me that he would use the multiple density construction to limit it to 'fit' inside the desired horn throat perimeter if he didn't want to roll off its HF response with a front filter chamber or phase plug. In this scenario, the horn's expansion would define its polar response as it would be merely acting as a waveguide (WG).

GM

[bfish]

This Life Magazine shot from the French Restaraunt in the French Pavillion gives a view of 3 of the 4 "horn huts". (click image to enlarge)



Prelinger has some nice early Kodachrome (silent ) reels of the '39 WF. If you pause this one at 1 minute 16 seconds in, you'll see a different view of the horn huts with some of the fountains active;

Internet Archive: Details: [Amateur film: Medicus collection: New York World's Fair, 1939-40] (Reel 4) (Part I)

[Panomaniac]

They were right out ther ein the middle of the fountain, weren't they? Crazy!

The 1930s never fail to amaze me. What a decade!

[bfish]

Yep. You can catch glimpses of the low, dark structures in this night performance;

YouTube - Lagoon of Nations at the 1939 World's Fair

One has to just imagine the music accompaniment in the silent flicks.

Today's Bellagio display is certainly impressive, but hardly original...

(And it doesn't have flames, fireworks, or 14' horns with 500lb drivers either).

[hmolwitz]

A little more info is available on the Lansing Heritage site if you search on Cinaudagraph.
I had a Cinaudagraph 10" and 15, the 15 was described as full range, and succeeded up to about 10k, a nice sounding driver beautifully constructed which wound up in the hands of a collector in the Chicago area, I threw in a 10 just to keep them together....
Harry