Diaphragm works in progress. Share your ideas.

[larryh]

Hello all,

Several of us have been discussing off the board ideas were working on to develop diaphragms, mostly for edison, that may reach the levels of tone and sound that add to the enjoyment of owning these great machines and records. I wondered if perhaps there are a number of other "tinkers" who may be trying out ideas who would want to share ideas and discuss progress? Who knows what might be possible?

I have the thread on the Edison Online Discussion Board on "Designing an Edison Diaphragm" but its so far been mostly my thoughts over quite some time of how I arrived at what I now call the True Tone Diaphragms, for both Disc and some models of Cylinder machines. My intention from the start was to encourage others to to do the same and hopefully improve on my designs. That board has become rather sparse in attention over the years so perhaps we can move some ideas here to continue the search for exciting sound for owners of Edisons.

If you have some thoughts or hopefully design ideas it would be fun to share how the progress is going. We may want to provide some for others of like mind to get feedback on what others hear.

If you don't wish to post ideas to the group we could always PM them as well.

Larry

AcousticEdison (On Youtube)

[Phonoboy]

Linkage Cord jig #1. Result, according to Larryh, the cords are not quite long enough, but close.
hope the have more to report soon.

[larryh]

Mike,

Would you want to describe how this is used?

Larry

[Phonoboy]

Mike,

Would you want to describe how this is used?

Larry

Sure; what I did was take a measurement, and drive a pair of nails in a scrap board then clipped off the head. I then took some silk cord, bent one end around one nail and secured it with a peace of gasket tube, cut on one side. After doing the same with the other end, I applied epoxy to permanently secure the two loops, and slid the cord up off the nails.

[Victrolaboy]

Mike,

Would you want to describe how this is used?

Larry

Sure; what I did was take a measurement, and drive a pair of nails in a scrap board then clipped off the head. I then took some silk cord, bent one end around one nail and secured it with a peace of gasket tube, cut on one side. After doing the same with the other end, I applied epoxy to permanently secure the two loops, and slid the cord up off the nails.

Very clever.

[winsleydale]

Has anybody yet attempted to install a modern speaker cone into a reproducer? I imagine that would have the potential to really bring out the bass. It may be difficult to clamp the rubber gasket in without ruining its shape and thus its pliability, but I think it could sound quite good if done properly. This is all theoretical, of course.

[larryh]

Actually I believe a design of some years ago now used the small cone for a speaker glued to the diaphragm. I don't recall how it worked out but since it was short lived it may not have worked to suit the design?

Larry

[winsleydale]

I am thinking not of attaching it to the diaphragm, but replacing the diaphragm entirely with it.

[Victrolacollector]

I have also thought of using a rice paper type diaphragm in a Victor reproducer. I think the sound just might be more like a diamond disc?????

[Edisone]

I am certain that a plain paper cone, identical to the speakers of today, needs to be much larger than what would fit in an acoustic reproducer. They're too flexible to push any amount of air, as in a horn system. Remember that the only successful paper diaphragms of the acoustic era were LARGE - Pathé Actuelle, Pathé Diffusor, and the HMV/Victor Lumiere pleated diaphragms were all about 12" or larger. Acoustic reproducers depend on a diaphragm which PUMPS air via a stiff center & flexible edges - not flexible across its own surface, as paper. Thus the stamped patterns on Edison and Columbia copper diaphragms, the earlier built-up mica diaphragms, the cork-centered Diamond Disc/Amberola, the common mica held by soft rubber gaskets, and the later stamped aluminum with either thick centers, a central plate or Victor's "spider".

An odd combination of the two ideas: I have a Linguaphone with what appears to be an Orthophonic-era delicate aluminum diaphragm, plus soft rubber tubing as gaskets. The design called for "tucking" the outer gasket into place, but trying to squish it in place without deforming the diaphragm was a maddening nightmare! They must have had some trick which I couldn't discern.