Big nipples

[neildavis]

PE only had 2 of the 1009 diaphragms in stock, so it may be a while before I can finish this. But at least I'm done with the smell of burning steel. It uses a column of 5/8" neo magnets that go in the inner pipe.

Uncut nipples:


Cut and primed:


This is the design that uses smaller nipples.

[Soundslike]

Re: Big nipples

Who's going to be the first to ask, "What the heck is this?"

[Deward Hastings]

Re: Big nipples

Who's going to be the first to ask, "What the heck is this?"

I'm seeing an omnidirectional tweeter, but the "magic" is escaping me. Accordian, maybe, like a circular AMT?

[JRT]

Re: Big nipples

Who's going to be the first to ask, "What the heck is this?"

Looks like the start of a DIY quasi-omnidirectional tweeter, a cylindrical ribbon radiator. That's my guess.

Edit: Deward beat me to it...


.

[neildavis]

Re: Big nipples

...Accordian, maybe, like a circular AMT?

See figure 11:
http://www.google.com/patents?id=Yjw...page&q&f=false

For this design, the magic will just be 4 of the 1109 diaphragms, wrapped around the inner structure:


I actually wanted to make a much larger one using 8 low-cost diaphragms from Hygeia (for the RT-5001), but I'm having some language barrier problems. If anyone speaks Chinese and wants to help, send me a PM :o.

I've got a diaphragm ready to etch for the small nipple version, but it's been sitting around for a couple of years :(. I thought maybe doing the larger version would get me motivated to finish off the micro version.

The magnet structure for the small version is on the left:

[Wolf]

Re: Big nipples

Who's going to be the first to ask, "What the heck is this?"

A 360 degree dispersion AMT. He's been talking about for quite a while now.

A 'clone' of the attached below...

Later,
Wolf

[neildavis]

Re: Big nipples

A 360 degree dispersion AMT. He's been talking about for quite a while now.

I've made many, many Heils, and even wrote a DIY "how-to" back in 1974 for AA (see the link). But I sort of got burnt out on them, and I've had trouble getting motivated to finish that micro version. But I'll get there eventually.
http://www.audiodevelopers.com/misc/...icle/index.htm

My wife got me a a rather large lathe for Christmas (1948 vintage), so I've been thinking about cylindrical speakers lately :D Once I gear it down it should be able to turn 12" cylinders.

A 'clone' of the attached below...

Nope...that is a true ribbon, not an AMT. Hygeia makes Heil drivers that they call "Aero Striction Tweeters", but nothing circular. I don't know of anyone who has made a cylindrical Heil. And I don't think anyone has tried making an omnidirectional "micro Heil".

[Soundslike]

Re: Big nipples

Very interesting..., thanks gentlemen, to all who offered an explanation..

Ron

[Paul W]

Re: Big nipples

Neil,
How would you compare/contrast the diaphragms PE sells with the Beyma TPL-150 diaphragm?

I'm thinking a flat neo motor would be a piece of cake, but I sure don't want to tangle with the diaphragms like you did! I was blown away when I first read your article in the 70's.
Paul

[neildavis]

Re: Big nipples

Neil,
How would you compare/contrast the diaphragms PE sells with the Beyma TPL-150 diaphragm?

It looks like the Beyma units use a Kapton film, which will result in better power handling (very high melting point). The PE units are either polyethylene or mylar--actually I haven't even opened them up to look at them. My preference is for the softer polyethylene material due to better internal damping. As long as the material is fairly thin and lightweight, the sound should be comparable, although some people claim to hear differences (ESS used all 3 materials through the years).

The diaphragms I wanted to get are the ones made by Hygeia--$18 vs $70 for the units from PE (1107). But after several rounds of emails, each time asking how many units I wanted to buy, I gave up on Hygeia, at least for now.

I'm thinking a flat neo motor would be a piece of cake...
Paul

I've made a number of flat ones, and they are usually fairly easy. However, probably the easiest uses 2"x3" steel bar stock. See http://home.comcast.net/~neilandbarb...DIY1/index.htm.

The mini-Heil shown below is also fairly easy to build.

...but I sure don't want to tangle with the diaphragms like you did! I was blown away when I first read your article in the 70's.
Paul

I had some fairly good success with etching the diaphragms, but for some reason I just can't get motivated to make some more. I even had a template manufactured so that I could UV-cure etch resist, but I've never used it...

[Paul W]

Re: Big nipples

What is pleat depth of the different diaphragms? (PE 1107, 1108, Beyma, Hygeia)

[neildavis]

Re: Big nipples

What is pleat depth of the different diaphragms? (PE 1107, 1108, Beyma, Hygeia)

That's a good question. If I'm going to use a factory-made diaphragm I usually just buy one and make the gap in the magnet structure to fit. But it would be nice to know before buying. :rolleyes:

In general, the larger diaphragms use thicker traces and are deeper as a result. I'll measure my 1109's when I get back home. I don't have a 1107 or 1108 right now.

When I was looking at using standard pipe sizes I found 3 combinations that would work to make a cylindrical Heil--see the chart below. Obviously, knowing the diaphragm depth would help. Hygeia finally got back to me about the small diaphragms that they use in the RT2002--about $3, with an apology about the high price due to the small quantity that I wanted. :D So I'm kinda jazzed--a high-quality omnidirectional Heil tweeter that can be build on a low budget is exciting stuff.

BTW, the magnet structure in the first pictures of this thread uses the 2" and 1-1/4" pipe nipples. I wanted to build the version with the 4" pipe, but 8 of the 1109 ESS diaphragms were too expensive for a prototype, so I scaled back.