Cinaudagraph - The mother ship of New Enland speakers

[Andy]

I posted in the Bozak forum about a Speaker from 1930's in which Rudy Bozak was said to be the chief engineer. The speaker is the Cinaudagrah PA speaker made in Stamford CT. Their most famous speaker was one made for the New York Worlds Fair 'The Super PA 27'....a 27" inch speaker with a 6" voice coil, and cover a range of 25 to 10,000 cycles. Said to be the largest loudspeaker, shipping weight, 600 lbs. !

This New England made loudspeaker looks to be the largest made ? Klangfilm of Germany made some amazing speakers, but I think 22" was their largest.

[mrdb]

There is an article in the February, 1963 issue of

Electronics World written by Charles McShane, chief engineer of Cinaudagraph Acoustical Labs entitled "Hi-Fi Loudspeaker Cones". I understand that he had much to do with the design of the AR3a tweeter with Roy Allison.

The intro under the title states: "We know one speaker sounds different from another and we are beginning to understand why. Here are some design and construction variations that produce such differences".

The article discusses the influence of different cone materials, mass, compliance, edge suspension types and other parameters on the frequency behavior and distortion of speakers, with an emphasis on low frequency drivers. He discusses long throw woofers and the effect of long voice coil versus short voice coil relative to the magnetic gap. He also shows dwawings of cone noding at various frequencies and what can influence it.

Interestingly, at the end of the article is a separate short announcement of a Live-versus-Recorded concert of the Fine Arts Quartet at Harvard University. The speakers used were AR3s. The unknown author states that it was frequently difficult to tell when the musicians were playing or the speakers were. The author noted that the only difference heard was a slight increase in reverberant sound when the musicians were playing.

Bob