The Talking Machine Forum — For All Antique Phonographs & Recordings

I think that the diaphragms are normally made from mica or aluminium.

I wonder, has anyone ever made their own DIY diaphragm - maybe even from a different imaginative material ?

Some gifted amateur repairers have made dies to stamp out aluminium diaphragms. Many years ago I saw the process demonstrated on TV using an aluminium pie dish!

Since I started repairing soundboxes, I've been keeping in a box 'for experiments' every conceivable small bit of material that I find suitable for a diaphragm. I've joined so far small bits of cardboard and hard paper, aluminium or metallic plates, polystyrene of several thickness or density, wood, plastic, etc etc. Since a boy I developed the rule of scratching the edge of every thing that can be converted into a diaphragm to test how it sounds.
So far, I've tried diaphragms made of thick and thin paper, plastic, aluminium, thin, etc.
My very first soundbox was a self-made one, and used a thin Kraft card paper diaphragm.
I've made aluminium and thin sheet diaphragms for a Meltrope III, and they were quite decent. I made the annular corrugations and the central cup by hand, pressing the sheet carefully and forming it, using adequate hand tools and working the soft metal sheets placed over a buffing cloth. It is easier to do it than to explain it. With the adequate metal sheet, anyone can make its own diaphragms...!

Some years ago I thought about experimenting with diy diaphragm using an HMV No. 4 soundbox. Regarding the material for the diaphragm itself I think the best could be carbon fibre (light, flexible yet strong material) but difficulties in finding samples of it of correct thickness stopped me.

Very interesting indeed.

I think I will experiment then with a spare soundbox / reproducer I have.

I've done quite a bit of experimenting with DIY sound boxes as well as other aspects like horns and turntable systems. I've put all my results up on YouTube. This video here shows my latest sound box design and a sound comparison with variations on the design and a HMV 5b:

https://youtu.be/kZ9Wskmrs74

A nearby collector has been making his own for a number of years using some type of thin aluminum... he cuts them out with a drafting compass with a phonograph needle instead of a piece of lead, going around and around until it cuts through. I cut out a rough sample from a soda can to see how it sounded when dropped on a table... the result was good, it rang like a good piece of mica. The sides of soda cans are thin and easy to cut with scissors. I don't know how a bottom would work, but they are somewhat thicker...

I would be fun to make a more compliant version like a loudspeaker and then back-load it by putting an enclosure on the side of the reproducer. This would undoubtedly give better bass response. You might even be able to remove the driver cone from a good tweeter and install it in the reproducer. An aluminum ribbon-tweeter would already have the ribs you need, but they are in a straight line so may not work too well...

Way back when I bought my first cylinder phonograph, (an Edison Home), it was needing a reproducer. I borrowed one from a friend of my dad's, took it all apart, and made a copy of it from scratch, including the diaphragm. I used copper of the correct thickness. I made one half of a die out of aluminum. It had all the annular grooves in it as it should. I then poured lead into the aluminum half, let it cool, then pulled out the lead. This formed the other side of the die. I then inserted my copper disc and pressed the lead/aluminum dies together, and presto: an Edison diaphragm. The only thing I bought was the stylus & stylus bar, (from Neumann Miller). (I was still in high school and couldn't afford a real Model H reproducer, but I could make one!)

Thank you everyone for your advice and very interesting experiences.

So ....... last weekend we went to the supermarket and bought a duck. I noticed it came in quite a thick aluminium tray. The idea being you bake it in the tray with some kind of 'roast in a bag' covering.

Anyway, you've guessed it, I immediately thought the aluminium tray would potentially make a good diaphragm - so I tried it .. and surprisingly it does ! (Really !).

As I say, the aluminium was quite thick but produces great, smooth sound. I use it on a floor standing gramophone and strangely it now sounds better with the lid open.

The whole process took about 15 minutes - after I soaked a few of the soundbox's nuts and screws in oil for 3 days. Nail clippers used to cut the circle shape.

Brilliant !