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Nor was the Exhibition designed by Victor, but rather by Robert L. Gibson (U.S. Patent No.750,460). I read somewhere that Gibson received a 25-cent royalty for each Exhibition sold - - which alone would have made him a very wealthy man!Phototone wrote:The Orthophonic soundbox with the corrugated aluminum diaphragm was designed by Western Electric engineers, not Victor.
I totally agree with this statement. It seems to be a toss up between the Victor Exhibition and Victrola #2, both are good soundboxes to play the acoustic recorded records (prior to 1925ish). However, the Victrola #4 with its larger diaphragm and the needle bar set-up, was a better improvement, it allowed better movement in the needle bar to play the new electric records in addition to acoustic records. The Orthodontic was the next of all of the Victor soundboxes, especially in playing electrically recorded recordings. Like Greg said, it really was the exponential horn that made the difference.gregbogantz wrote:This is just my opinion and not based on any scholarly research. But before the introduction of the Victor #5 orthophonic reproducer, I don't believe that there was any real science applied to reproducer design. It was cut-and-try, and buy-guess-and-by-golly. "Gee Ralph, that little twiddle that I did to the needle bar sounds better, don't ya think? We'll apply for a patent with some jibberish claims that really don't mean anything and then let's put into production". You see all kinds of little tweaks and twiddles done to the basic design of the reproducer from the very first Victors all the way up to the #5, and in all the competitors' designs. And they all turn out to be pretty much the same basic design when you ignore the details that don't really contribute much to the sound of the units.
But the Victor #5 was actually designed from an analysis of the need to match the exponential horn that these were used with. Western Electric made a big deal about the "matched impedance" blah blah of this design, but most of that was pretty much hot air so far as the reproducer goes. The soundbox design is STILL not much different in principle from all the earlier ones. However, they did manage to address some significant issues such as the use of a more compliant diaphragm as realized in the use of the corrugations in the aluminum and the need for reducing the moving mass of the vibratory elements. Beyond that, the "matched impedance" jargon was mostly sizzle used to sell the newfangled steak. The biggest improvement in the Victor ortho phonos was the use of the expenential horn which WAS in fact a result of proper mathematical analysis applied to the problem of designing an mechanical impedance transformer that is required to couple the high-pressure output of the reproducer to the low pressure emission from the mouth of the horn. That's what the horn is - a mechanical impedance transformer, not an amplifier as it was commonly referred to in early advertising.
Here's the US Patent data: http://pdfpiw.uspto.gov/.piw?Docid=0075 ... first+pagephonogfp wrote:Nor was the Exhibition designed by Victor, but rather by Robert L. Gibson (U.S. Patent No.750,460). I read somewhere that Gibson received a 25-cent royalty for each Exhibition sold - - which alone would have made him a very wealthy man!Phototone wrote:The Orthophonic soundbox with the corrugated aluminum diaphragm was designed by Western Electric engineers, not Victor.
George P.
A book you might be interested in reading is "Modern Gramophones and Electrical Reproducers". It was published in England in 1929, only one printing. The first 7 chapters are about acoustic reproducers, horns, and tonearms, chapters 8 thru 11 are about electrical reproduction and recording, speakers and amplifiers.johnwilla wrote:I am curious about the development of the sound box as exemplified by the Victor No. 2 and Exhibition sound boxes. I wonder if any member of the listserv is aware of documentation of research, notes, etc., on this subject? Searching for patents in Google Scholar is pretty daunting, as is a search of the patent gazette. I read the pages in Victor Data Book about sound boxes, and there are some references there to documentation the author found in preparing the book. I wonder if there was any effort to record experiments with these at Victor? Was it hit-and-miss? I assume that by the time of the orthophonic soundbox, there would have been quite scientific approaches to establishing the size of the diaphragm, configuration of the spider, etc., etc., but that is the kind of thing I am curious about with reference to the earlier versions. Anybody know of a handy dissertation on sound box development?
Thanks in advance. I am always grateful for the considerable help of members.
3) Robert L. Gibson was the assignee, as noted at the top of the first page of the text.Henry wrote:
Here's the US Patent data: http://pdfpiw.uspto.gov/.piw?Docid=0075 ... first+page
Notes:
3) No Robert L. Gibson is found, but Henry Jones is the signatory (see p. 5 of the full document text).
4) The text description sounds like the Exhibition, although the drawing differs from the sound box appearance as actually produced. Note patent date January 26, 1904.
