AMT 3 DAMPING QUESTION

[Hannibal Selector]

Are there any AMT 3 owners out there that can give me a good
description of how they were originally stuffed? I want to build
clones and have the big AMT's, the recommended Eminence
1040SF's and Alpha 6's, and have the x-overs covered (triamp
via active). I have the dimensions pretty well worked out, but
these things were overdamped BR - I would like to be able to
faithfully reproduce just exactly how these were stuffed, in case
the design called for more or less damping than other overdamped
BR designs. Any details would be GREATLY appreciated.
You know, was it just walls and a sheet behind the drivers? Two
sheets? Full wall-to-wall? And if so, was it loose, middling, tight?
Was it all sheets? All batts? A combination of both? Something
else? Dacron, 'glass, wool? Any felt or foam on the walls? Ditto
for the mid-bass containment tube, how was it damped?
I just don't have access to one for a "Chinese blueprint" and not
sure I ever will.

This is one detail I haven't been able to find on any thread anywhere,
and I have looked high & low. Maybe it's out there, but I haven't
seen it.

I posted some (probably too many) AMT 3 questions previously in
Planars & Exotics and got no response, so maybe here in Multi-Way
is better. Or I'm open to suggestions on where to post as well.

Any help is greatly appreciated.

BTW, for any AMT/ESS junkies here who haven't run into this
awesome gallery of ESS ads, here's a link posted originally,
I THINK, on AK, by Cactus Jack (hope I got his name right):

* Michael Otto's Archiv * - ESS_Lautsprecher

Clicking a thumbnail gives you a not-so-big shot of the ad, but click
again and you get full-size.

Here's a thumbnail - if I can make it work - of ads for the AMT 1 Tower
and the AMT 3 from that gallery. It shows how the Tower, which is
transmission line, is stuffed. No such luck on the 3.

[Hannibal Selector]

OK, thumbnail didn't work, here's a link to that one page -
click on it to get full size:

* Michael Otto's Archiv * - ESS_Lautsprecher/ESS_amt_1+4+5+tower+rock_monitor

[puppet]

Don't know how you stumbled on that link but ..... thank you for posting it!

Can't help on your stuffing question though ... .. well other than to say you have the advantage of tuning the LF for your room by experimentation with the density.

Since you have those Eminence (1040SF) drivers .. do you happen to have any thing to add besides what is posted on OCS .... (like freq. response graphs)?

I'm in the planning stage of a bass cabinet for my pair of heils. It was recommended to me (here) by a knowledgeable fella (John Busch) that a couple Seas H1411's in a sealed enclosure might work pretty nice too. I realize the 1040SF's are better suited for the BR designs ... but the 12" driver in that series might work well for a sealed alignment. If you happened to have a graph for the 10's a guy might be able to get a feel for how the 12's might look on paper.

Good luck on your build!

[Hannibal Selector]

Hey Puppet.
Sweet link, no? I thank that German (I guess) dude for putting it up
in the 1st place, and Cactus Bob (IIRC) over at AK for posting the
link. Maybe Cactus Jack. Arrggghhh, senior moment.

As for the 1040SF, all I have is what you have, I'm thinking.

I know nothing about sealed box design and have only the barest grip
on T&S parameters, frankly. If you're bound to a sealed design I can't
help you other than this: the AMT 3 already acts to a certain degree like
a sealed cab, and the 1040SF suits it beautifully, according to those that
have used them in their 3's as replacement/upgrade. If you're determined
to stick to a pure sealed setup, maybe the thing to do is shoot an email to
OCS. I didn't have to, because all the homework has already been done
for me - by ESS and various AMT 3 junkies.

Now if you're not locked in to sealed cab, you just might want to explore
the 3-clone route yourself, I got a lot of good information about that,
much of it from the '3' fans at AK. Or clone the AMT 1 Tower if you like
the TL idea. Planet 10 here has done that, I believe. You could thread
search by his name. I saw him mention using some Fostex 9" driver IIRC,
for what I ASSUME was a Tower clone. Myself, I see building a Tower
clone with added mid-bass transition driver as another great way to go.

Either way, after reading tons of AMT threads, I'm convinced that my
first instincts from eons ago were right - that 3-way is the best way
to frame a Heil. People have been known to shoehorn in a mid-bass
sub-enclosure between the AMT and bass cab on an AMT 1, for that
matter. There's one that usually shows up on image results for just about
any AMT google search; you've probably seen it. I'm told the driver in it
is an Eminence Alpha 6A. The other driver that I've heard '3' junkies
rave about is the Audax HM 130CO, now hard to get. I've seen them
still in stock @ some vendor in Britain, and Madisound told me maybe
they can get some around late February.

Lastly, if you do go '3' clone or close and want a passive 3-way network,
Automojo @ AK has done a lot of work on those; maybe try try a thread
search by his name there.

Have fun/best of luck with your build too.

[Hannibal Selector]

OK, it's Cactus Bob, not "Cactus Jack".
Break out the wet noodle, I took dudes name in vain.
Also in the AMT line-up of usual suspects at AK are
Gordon W and Ron C, as well as Automojo.

Check this out from DIYA, especially post 9:
ess amt 1c
Assuming you haven't already seen it, and the link works.

[Hannibal Selector]

Still could use knowing how the AMT 3 was originally stuffed, as per
my original post... Anybody?

[Hannibal Selector]

Bump.

[Hannibal Selector]

Bump.

[IBJamon]

Hey there. I just got AMT 3's today, and coincidently, one of each kind... 1 ported 1 sealed. I have a thread on AK going on about it with pics. Anyway, I opened both of them up and they are very tightly packed with stuffing; the sealed one well packed, and the ported one is so tightly packed it took significant effort to see the crossover.

IBJamon

[automaticmojo]

I will have to recall, but the AMT3's use around 3 lbs of stuffing per speaker. This stuffing isn't your traditional poly stuffing, it is very pillowy and loft, but clumps easy and need to be pulled apart before packing.
I would certainly use Acoustistuff if I was building a clone.
The Alpha 6A would be my budget choice for a transition driver, the Audax HM130CO would be a upgrade choice. Both work very well-the Alpha breaks in quite rapidly, while the Audax takes at least 50 hrs +.
At first I preferred the Alpha to the Audax, till I did some research and realized carbon fiber takes forever to break in, After break in it matches up perfectly, and has the clarity edge over the Alpha, and sounds more "natural".
The sotck AMT3 transition tube is around .23 cuft in volume and stuffed fully.
For coils, Menicus Audio IMHO has the best custom wound, large gauge/low ESR coils out there, and priced right.
Erse Pulse X caps are my choice-order them directly form Erse-they do the job without adding theeir own "sound", just what you want. Mills resistors get the job done as well.