The Talking Machine Forum — For All Antique Phonographs & Recordings

I received the diaphragm as promised by Phonoboy, (Mike). I have tested it an found it to be pretty decent for a first attempt at producing a diaphragm. I have put up here a version with his and mine of the same selection, and electrical recording of "Just a Night for Meditation"

Its a bit difficult to tell the differences as the camera pulls in the volumes at similar levels. In person the test one is less pronounced but certainly a good start. The diaphragm it self needs some tweaking to get the linkage and basic design a bit closer to what one would expect, it tends to warp around the edges an the link was too long but all things that can be figured out I am sure. I noted that some instruments tended as the vocals to come across very well while some other odd things like bells were way in the background compared to quite upfront and loud on mine. I have found that getting the balance of sounds right is among the more time consuming problems but well worth it to fix if possible. Overall I was impressed how well it did now and the potential that it may have.

https://www.youtube.com/watch?v=F_ApihBnAEs (Phonoboy)


https://www.youtube.com/watch?v=Ykc244R_QJs (True Tone) (Acousticedison)


Larry H, "Acousticedison"

I hear what you mean about the bells, and I have a theory. Could the distant bell sound result from the diaphragm warpage?
Perhaps the tension across the diaphragm is not uniform causing it to vibrate unevenly across its surface.
Thoughts?

Its quite possible, When I sent a video to Steven M I sent a photo as well an his comment was that warped diaphragms will not produce the sound properly, so if you can figure how to get them flat it might make quite a improvement. I would like to hear that! It might be you could weight it down between two pieces of waxed paper so that it wouldn't stick to the diaphragm till it was dry? You will have to play with it an see how to best accomplish that.

Larry

What solvent did you use when laminating the rice paper? Frow mentions that denatured alcohol tended to cause warping, but grain alcohol did not.

Bill

Frankly, I cannot notice any difference in the sound between the two videos. It requires live listening to discern such differences, the distortions and compressions of recording devices and you tube tend to remove any subtlety in sound.

Lucius1958 wrote:What solvent did you use when laminating the rice paper? Frow mentions that denatured alcohol tended to cause warping, but grain alcohol did not.

Bill

I used hide glue

I think both diaphragms sound good. The Trutone, has a brighter, mid high for trumpets and the like. I noticed the deep bass on Phonoboy's diaphragm, and I found the slope in the 600-1.7k range pleasing, then a nice gentle rise in the 4-6k range also the sibilant's were natural. I had made some diaphragms of rice paper soaked in shellac and baked in an oven that sounded pretty good, I attached the cork with glue all, and used black, natural silk chord in a loop, I simply used flake shellac to make a button on top. Also made recording diaphragms of papers, the outer edge thin and then two steps to the middle. then took the circular diaphragm and then cut towards the middle and glued over making a cone shape, then soaked in shellac and baked in the oven until the paper was hard. I then coated the edge of the diaphragm with rubber cement in layers until the desired thickness and carefully set it on fire, and made sure the rubber only burned to make semi liquid gasket.

Phonoboy wrote:

Lucius1958 wrote:What solvent did you use when laminating the rice paper? Frow mentions that denatured alcohol tended to cause warping, but grain alcohol did not.

Bill

I used hide glue

According to Frow, they used shellac: hence the query about solvents.

Bill

CarlosV wrote:Frankly, I cannot notice any difference in the sound between the two videos. It requires live listening to discern such differences, the distortions and compressions of recording devices and you tube tend to remove any subtlety in sound.

Carlos. Your quite right. In person the rice paper version sounds more distant, but my camera pulls the sound up to compensate and You Tube also restricts some sound. I have noted all along that with my older camera, (although it does a fair job to my surprise) its not like hearing it in person by any means. Still the new design Phonoboy has created was an eye opener as to how well it did do. Getting it totally suitable is always the hard part.

Larry

larryh wrote:

CarlosV wrote:Frankly, I cannot notice any difference in the sound between the two videos. It requires live listening to discern such differences, the distortions and compressions of recording devices and you tube tend to remove any subtlety in sound.

Carlos. Your quite right. In person the rice paper version sounds more distant, but my camera pulls the sound up to compensate and You Tube also restricts some sound. I have noted all along that with my older camera, (although it does a fair job to my surprise) its not like hearing it in person by any means. Still the new design Phonoboy has created was an eye opener as to how well it did do. Getting it totally suitable is always the hard part.

Larry

This is an ongoing experiment ,as I'm sure you all well know. I would like to thank you all for your interest/input. I am surprised by the number of people checking this post out.