Image Request: AMT / Heil diaphragm.

[Grumpy_Git]

Hi All

As per the title above, I was wondering if anyone had a picture of an un-folded AMT diaphragm. I'm in the middle of bodging together a small clone or three to fill my evenings and want to keep the whole project under 60GBP so replacement diaphragms are out.

So far I've spent:
25GBP on mild steel.
30GBP on magnets.
10GBP on various thicknesses of Mylar/PET
0GBP on alu foil from the kitchen.

Ideally i'd also like to know the overall dimensions and the number and depth of the pleats so I know how much density to achieve in MY folded element. I'm also nosey for just what they look like!
I've had a rough attempt working but think that I need more pleats so need to narrow pleat width and increase the number, parallelling some of them, as Re was already high.

I've searched all over the net and there are no pics that I can find, surely someone took a pic or two when they pulled out a duff element for replacement.

Pics of everything WILL follow but not till I'm finished and they work.

Cheers

Nick.

[bolserst]

Originally Posted by Grumpy_Git

I was wondering if anyone had a picture of an un-folded AMT diaphragm.

You might check out the DIY AMT article posted here:
Hornloading the Heil AMT1

There is a picture of an unfolded diaphragm on page 22.

[Grumpy_Git]

Originally Posted by bolserst

There is a picture of an unfolded diaphragm on page 22.

Thanks for the heads up but I had already seen that and I have the original Neil Davis/AA article (I have been searching), I was hoping for one of the OEM diaphragms, I shall keep looking.

Nick.

[Baldin]

I'll mail some files for you, if you provide an address which will accept a 2 Mbyte file

[Grumpy_Git]

Baldin

Thank you for the offer, you could try:

Nick at kowal1 dot fsnet dot uk

replacing the at for @ and dot for . as required.

Nick.

[Baldin]

Should be in your inbox
/Baldin

[Grumpy_Git]

Baldin

I've just re-checked this thread and realised the email address I put up was wrong, my apologies, 800mile road trips tend to make me overly tired.

would you mind re-sending the email but to:
nick at kowal1 dot fsnet dot co dot uk

Sorry for wasting your time and thanks again.

Nick.

[Grumpy_Git]

Two items in this post.

First: Thanks to Baldon for his email.

Secondly: I've completed the first of the tweeters and it seems to be working nicely when i just run it instead of the tweeter in my main system so progress continues on the other two (I want them all across the fronts of my main system) I will try and get some freq responses done next week.

Now the reason for my post. I had to sell all my spare drivers some time ago and I would like to build a nice low/mid section to match these tweeters.

I was thinking cheap transmission lines, and the cheapest drivers I've seen recently that appeal are the Eminence Alpha 8A. does anyone have an opinion on these before I buy them or download the MJK worksheets. Basically I want a low cost TL and I dont really want full range, so fostex are out, some suggestions of completed projects would be nice as time and cash are limited right now.

Thanks

Nick.

PS: cant seem to upload photos or create albums etc.. anyone know how to do this?

PPS: found it

[Marveloudio]

the magnets are badly placed , only half of the stacked sheets have contact to the pole surface , a lot of flux is wasted , change the geometry for more efficiency ..

[Grumpy_Git]

Actually the magnets contact all the laminations as the openings/shorter laminations have 45 degree cuts reversed from the longer pieces so there are no gaps.


Nick.