Hey everyone , been gone off here a while, got a new computer and lost all my sites. John helped me find my way back.. Since I returned to enjoying Edsions last spring I have tried all kinds of new diaphragms with little success. Steve Medved was kind enough to give me a Waltrip foam type all in one diaphragm which no doubt was one of the best new designs to come along. I found it very hard to tell the difference in it and the original. As a matter a fact after going through a bunch of original diaphragms I finally reinstalled the Waltrip. Now that winter is set in and I have free time to play, I have begun to try some ideas for a new diaphragm. It has been a week nearly now, and I have done little else, its sort of becomes all consuming. Lots of lousy blasting poor tone tries. But I have had two that reached a very reasonable sound range with greatly reduced distortion compared to my other new "soda carton' models. I am finding that even if one turns out fairly well, the next almost just like it doesn't! I wouldn't ever say they sound as good as Edisons, as they don't, but the two that worked fairly well do have some very fine points so far. Wondering if any others out there have ever dabbled in creating a diaphragm and might like to discuss ideas?
To be truthful Larry, I've tried the "soap box/cereal box" reproducers with the dental floss hot glued to the back and honestly, I don't care what the guys that make these say, they don't hold a candle to the original diaphragms as far as I'm concerned. Knowing how tight old Tom was with a buck, I'm quite sure he tried a diaphragm that was quite similar to the ones that are out today and found they were as lacking then as they are now. But I'm sure to get flack for this so fire away.......................
Well I have two versions that show promise.. Its a lot more complicated than you might think. If something does great with hot bands, it may do lousy with a bass singer or a piano.. the one diaphragm I made has startling piano and string sound, but has a tendency to break up now and then enough that you can detect it. On a bass singer, on one record of his it goes through great, on another it buzzes on quick vocal changes. I think edison did make 1,200 before he got one he could live with.. I know I am not going to get that perfection tinkering here at home, but for people that like dance bands I think I am getting close to something better than what is available. It will probably take some time to get all this settled in.. Small changes make big differences and completely effect the tonal range.
This is why Edison had a different diaphragm for his Dance & the latter Edisonic(New Standard) reproducers. They were thicker and could handle the improved records. I'd love to hear your diaphragms when you perfect them.
Having done little else for a week now things are somewhat frustrating. I get a pretty good result that over night is deteriorating somehow.. Occurs to me it has to probably be the glue. I think I have an over all design that is pretty good, but still have about three more layouts to try for overall sound. Darn near burnt my self out on it so far.. But today is a new day.
Actually I am gluing pieces of shellac coated paper in a series of rings, reminiscent of the orthophonic diaphragm if that makes any sense.. What I found was that the first one that actually was strictly two flat sheets shellac coated and glued together was surprising, particularly while it was new. As it aged the paper became more hardened and had a tendency to warp. The original sound I heard was quite clear, clearer than anything since, but it was lacking in tonal range. In that edisonic reproducer it was most amazing at first.. I hoped it might have been an answer, but quickly I discovered I couldn't replicate the sound I heard the first try.. that is how I came up with thinking that series of rings of varying sizes leaving some of the thiner diaphragm exposed might be part of the solution.. Here again, to my amazement the first crudely cut and put together one was very expressive but had a tendency to have even more issues with some buzz than the first one. But I figured it was worth perusing.. I hoped somewhere long the line to hit a combination of ways to put it together that might be at least reasonable. So far that has gone on all week.. I don't know how many little diaphragms I tired, most not working.. I have honed in on trying to get the one that sounded best to work better. That is where the various glues come in and maybe the amounts of shellac. At first I was coating the whole thing with thin coats as it was put together but quickly realized that wasn't working and getting worse. So now it is the less is more trials.. Hope someday it will work..
It is back to the drawing board.. some of the ideas I had showed good promise, but time is the enemy of amateur designers. The materials I am using while good when first put together, within reason, are refusing to hold up after aging.. A tendency to warpage and hardening, neither of which so far I have been able to overcome with the current design.. I guess I needed a break. I have done nothing else for over a week. The search will go on and I will keep tweaking the design I started with, who knows maybe some other unthought of variation will work? Most likely though I will have to start looking at different materials. One starts to see the simplicity of cutting them out of soda cartons, faults and all..
Good thing I didn't give up too soon! Well I didn't intend to give up anyway.. I made a change is the basic paper I was using but stuck to one of the more promising layouts from the previous one and wholly cow.. this thing will for sure knock your socks off.. At least on the ones I have so far tried.. Now if I can just get it to work on several more like it I may have something here..
So far so good! This morning I am getting about the same results as last night. About as crisp an attack to instruments I have heard, at least on anything new.. Classical pieces reveal a depth of sound I had not heard before.. I just did a direct "soda carton" diaphragm test, and while for the simplicity of design it is able to reasonably play the record, when I put mine back in the tonal range was very apparent.. Warmth and depth of sound is the way I would describe it. And although I certainly don't wish to compare my design to Edison exactly, I will say that what I am hearing is no doubt what they heard when new. Mine may experience an occasional passage that will have a tiny feedback due to differences in design, and materials but for something home made I think it may have good potential. Today I will see if I can construct a number of them along the same lines and get within reason the same results.. then I need a few people with good ears to give it some trial runs on their machines...
Post by lukewarmwater on Feb 1, 2008 22:29:41 GMT -5
Well . . . I'm no expert either, but carbon (graphite) fiber is incredibly strong and dimensionally stable, flexible, but not stretchy. It doesn't absorb water (i.e. humidity). All sorts of things are made from it nowadays that require high strength to weight ratios and durability such as bicycle frames, aircraft parts, even guitars. I've included links to a couple of web pages including a wikipedia article below. Apparently carbon fiber is woven, so perhaps not airtight (I don't know), but I did see in the wiki article that it can also be had laminated with polymer which I suppose would make it airtight. I just thought it would be an interesting modern material to try.
I also wonder about the fact that no phonograph diaphragms were ever tensioned like a banjo hide is tensioned. Diaphragms are simply clamped in place. With tension, I would imagine that lows would be diminished and highs attenuated, but volume would be greatly increased. Would adding a dampener/weight to the diaphragm restore some of the lows and attenuate the highs while retaining volume? The Higham friction amplifier tensioned the diaphragm by pulling at the center resulting in greatly increased volume . . . so, what would be the effect of edge tensioning? The hide of a banjo (or drum) rests on a circular rim (called a tone ring) and the circumference of the hide is pulled tight. What if a small ring was added to the reproducer and the diaphragm was stretched tight evenly over the ring when the retaining ring was screwed down? What would it sound like? My banjos ring out loud and clear when I hit the strings or rap the hide. Tom Nechville makes a banjo where the hide tensions down with a helical ring like screwing the lid on a Mason jar eliminating all the hooks, nuts, and mounts of a conventional banjo: www.nechville.com/advantage.html. If the diaphragm was made slightly oversize, and a 'stiffener' ring added to the edge, the retaining ring could grab it and pull it tight over the 'tone ring' in the reproducer . . . . ??