Greetings from Loomis CA

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I've always had an interest in music and as good of stereo equipment as I could afford. I have an older pair of ESS AMT, and I'm beginning the inquiry to rebuild the crossover network. The Air Force provided my soldering training, and I've been working in computer technology for some time (1984). Found DIY using google and joined recently. Looking forward to sharing and learning. Take care ;-)
 
Welcome to the forum...

we have redone a couple of AMTs... the tweeters are marvelous, the rest isn't really up to the level set by the tweeter...

stock woofer/PR, mid added, new XO:

heil_3way.jpg


replaced everything but the tweeters:

heil-fostex.jpg


dave
 
Hi Bndkoss, and Welcome to diyAudio 😀 😀 😀

Once upon a time I used to work over at McClellan AFB but relocated to Tennessee in '06. There was a nice bluegrass / folk music band named South Loomis Quickstep that I heard quite a few times over at the old Shire Road Pub and I was wondering if they are still around or not. Used to fly RC models out by the HP plant before the plant was built!!! Good to another see a NorCal type around here. Keep your eye on the Burning Amp Festival thread if you would like to see just what can be done with these little toys some of us dream up around here. I'm using AMT 1's as I write but use a simple cap in series and cross them high at around 6 KHz. That keeps me away from a nasty little notch they have at around 3.5 KHz. I wouldn't try using them below 2KHz IMO.
 
Response to Zen in Tennessee

McClellan as an Air Force base has closed, but it's becoming a business park. I was in the 2049th Comm Group and we supported the microwave radios for radio shoots to Beal. :clown:

I'm getting ready to approach reworking my cross over network. You've indicated that you crossed over the network at 2khz. Did that improve the base, and if so, with which woofer. The couple of threads I've caught on AMT is to reduce the cross over from the 1khz to 800hz. :idea:

Thank you for the kind welcome, and I look forward to hearing back from you.:yes:
 
Hi Bndkoss,
"McClellan as an Air Force base has closed, but it's becoming a business park." I was a sillyvilian that worked over in the Met/Nav Depot Repair Section and many folks there did their military time over in the 2049th. Art Linn was my boss at one time and he was the Chief over at 2049 before he retired and became a "double dipper". Did you know "Duffy" Johnson? (Good Guy) I took an early retirement from Civil Service and along with some other folks helped to start up one of the "new" companies in the new "McClellan Park" (AAR-ATICS).

"I'm getting ready to approach reworking my cross over network. You've indicated that you crossed over the network at 2 kHz." I indicated that I'm crossed over @ around 6 kHz and I did that to avoid a couple of things. The AMT1's have a bit of a notch around 3.5 kHz and I knew that my 10" Pioneer http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-088 would go high enough to get me above that notch and help avoid having a xover in the middle of the vocal range. Take a look at the old Walsh 5 Remakes thread to get some ideas and see just how ugly you can make a speaker look if you really try!!!

The AMT's are a very fast transducer and also very efficient so I have often considered moving up to a "pro sound" woofer but just haven't got around to doing it yet as I'm pretty happy with things the way they are (until the "next great project" comes to mind). Which cabs you have to work with? Knowing that will help to give some better ideas about what to do with the woofer and xovers.

:cheers:
 

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Hi c2cthomas,

Thank you for the correction of your crossover frequency, and the picture. Would you help me understand the woofer config, it appears to be mounted vertical and has caught my curiousity.:scratch1:

I was stationed at McClellan 1976 - 1977, and our relationship was one of mutual discontent. Glad to reach sillyvillian status, and return to being a citizen. The names you mentioned don't ring a bell.

Thanks for the link to the Pioneer speaker. My speaker is still in the original cabinet. However, some of the creative solutions I've seen makes me wonder if that old adult wood working class may come in handy?

Talk soon,
Bud
:xfingers:
 
Hi Bud,
Hmmm - '49er's from the mid 70's??? Bob Smalling "Panama Bob", Larry Walton, Clay Dukes, Dan Rivas????

Some info about the "upside down speaker" in the photo
http://www.diyaudio.com/forums/showthread.php?s=&threadid=100390&perpage=25&highlight=&pagenumber=2

http://www.diyaudio.com/forums/showthread.php?s=&threadid=112904&highlight=

http://www.ohmspeaker.com/coherentlinesourcedriver.cfm

This construction allowed me (and others that went down the quasi "Walsh" path) to have a nice open sound that gets away from the "speaker box" sound. Same thing with Open Baffle designs - they get away from "the box". Once you get rid of the speaker enclosure you encounter a much more open and uncolored type of reproduction and I find it much more pleasant for long term listening enjoyment. BUT - it isn't everyone's cup 'o tea and your mileage may vary.

You have not mentioned the cabinet you have to work with so hard to tell if you need a remake or not. I purchased my AMT1's off flebay and one of em got crunched during shipping so I needed to salvage the tweeters (which is all I really wanted anyway) and make new cab's. The Walsh F remake thread caught my attention so I tossed together a couple of test mules to see how things would work out. Very nice results - depending on your taste in speakers. Omni speakers drive some people nuts and other folks love 'em. I use mine for 5.1 HT and in that configuration I'm looking to get a wide listening area and omni speakers fit that bill. Any howww - once I got into salvaging parts out of the cabs that were crunched I got to see 1st hand just how cheaply they were made! Almost anything you make would be an improvement - and that includes making some mistakes.

Attached is a photo of my modified Pioneer 10 inchers.

:cheers:
 

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Planet 10

The pictures you included showed an original ESS cabinet with the 3 way design. c2cthomas indicated he received a pair of AMT's and the cabinet was damaged in shippment. The conclusion was the cabinet was not well engineered. Did you find the same during your project.

In addition the woofer and passive radiator were relocated to a lowered position. How did you cut out the radius to receive them in the new position?

There was a second speaker in the pictures sent that looked, well, beautiful. The wood grain and stain were extremely attractive to the eye. Is this a cabinet that you produce, and does it retain the original crossover? If so, where did you choose the crossover. I've heard as low as 800hz and as high as 6khz. It seems to depend on the woofer purchased and its operational specification.

I would appreciate your reply and feedback.

Thank you.
Bud 😕
 
Re: Planet 10

Bndkoss said:
The pictures you included showed an original ESS cabinet with the 3 way design. c2cthomas indicated he received a pair of AMT's and the cabinet was damaged in shippment. The conclusion was the cabinet was not well engineered. Did you find the same during your project.


The original cabinet was tossed -- ir was of a quality where it pretty much fell apart -- and a completely new one was built. That the new cab had to accomodate some freshly built grils determined the size & shape of the cabinet. Original woofer & PR were used, Eminence 6" mid added.

Personally i preferred the 2-way with the push-push 9" fostex woofers.

dave
 
Planet 10

When you built the new cabinet did you replicate the original dimensions? It appears by your response the AMT pictured was a project for a customer. If you were doing it over your recommendation would be to retain the 2 way design? What would the cross over network design be, and which capacitors would you prefer?

Did you use 3/4" furniture grade plywood or veneered MDF?

My speakers have a baffle but no PR in the rear. What would the changes need to be to place them in the new cabinet?

I feel like my early days in programming Assembly when the instructor told me he deserved the credit because of all the questions I asked.

Thanks in advance for your patience. :wave:
 
For the 3-way ones we retained the AMT bass dimensions. The box was made of MDF (MDF is free and it was before i'd convinced Chris that it was worth it to buy ply (Baltic Birch). The 2-way had the smallest box we could fit the 9" Fostex in, built with Baltic Birch... they are pretty good up to 8-10k, XO ended up 1st order at 3k (with a honken big LPad attenuation on the tweeter).

dave
 
Planet 10

Thanks for the reply. I've been reading other threads and your participation has consistently been professional, informed, and courteous.

I would be interested in engaging this conversation around the 2-way design. I'm presuming it was the picture with the tall, cherry stained cabinet. This looked very attractive to me. I believe that I could build the cabinets because I've made furniture in the past.

However, I would prefer to know that the cross over network would perform well at the outset. Are you willing to build the cross over network? If so, what cost would you find appropriate?

Secondarily, do you have drawings for the cabinet design build out, and are there plans available to purchase?

If this goes well, then I'm hopeful that the ESS speakers that I've enjoyed for over 30 years will reveal the true potential present in the Heil AMT. :happy2:
 
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