Theater center ribbon tweeter mod

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wink

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I posted this on FB a few days back. I’ll post it here for those with a throwback system like mine.
A while ago I bought replacement panels for my Prodigy and my Theater center. Before replacing the Theater panel I considered upgrading to the Focus because I loved the seamless blend between the stat panel and a ribbon tweeter. I decided to forgo, for now, the upgrade and order the new panel from ML. While waiting for the panel to be made I had the idea to replace the dome tweeters with a ribbon. So I found a tweeter that had the correct measurements and ordered two of them. Once I got into the housing I realized I would have to modify/cut the housing to fit both, so I opted to install only one for now to see if I liked it. This way I could return to stock if I didn’t…..it was a great match; sounded really good. New panel, new ribbon tweeter. Time went by and I was itching to take it back apart and install the other ribbon, one above the other. Unfortunately I ran into an issue with their magnets opposing one another, so I searched for one larger ribbon instead. Found the perfect one. Sonic measurements were right as well as physical measurements in its own casing, so it was shielded too.
Long story, short, install when perfect. I had to cut the tweeter housing quite a bit to allow fitment, so had to repaint the housing.

Here is the link to the tweeter used:

C596BBFF-E653-4838-8EB0-F02BDED729B9.jpeg
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C596BBFF-E653-4838-8EB0-F02BDED729B9.jpeg
 

Brandon Hartwick

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That fitment looks OEM, nice work. How different does it sound with a ribbon tweeter? I'm a sucker for AMTs, I don't care what other people think, my Wharfedale Evo's use them and they're so great.
 

wink

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Much smoother presentation. It doesn’t have the sharpness of the small dome tweeters. This particular ribbon only extends to 18k htz instead of 20k htz for the domes.
 

Robert D

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I had a theater i that I sold last year and bought a new Focus to take its place. I could have sworn that ML told me they don't make new panels for center channels. Where did you get your's done?
 

JonFo

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Thanks for sharing the details. Very well executed!

This is indeed a great way to modernize a Theater.

Now, about the need for some absorption on the wall behind it to minimize the comb filtering ...
 

hillbilly

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I'm a little confused. Is the AMT the same as a ribbon speaker, like Aurum Cantus?

Also, did you change the crossover value at all?
 

BDH55

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Very nice job! (y) Personally though, while I can do a lot of different things, I don't think I would ever have the guts to try something like this...
 

wink

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I'm a little confused. Is the AMT the same as a ribbon speaker, like Aurum Cantus?

Also, did you change the crossover value at all?
AMT (Air Motion Transformer) I call it a folded ribbon. There’s also the Planar Ribbon which I think you’re referring to. The ribbon I used is a similar to the one that ML is installing in all their hybrid speakers now..
No, I didn’t adjust the cross-over, I left it a 3k Although this is a large ribbon that could be crossed at 1k if I wanted, but I like to get everything possible out of the esl before transitioning to the tweeter.
 

wink

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Very nice job! (y) Personally though, while I can do a lot of different things, I don't think I would ever have the guts to try something like this...
It’s a 20year old speaker which helped tame the nerves a bit, but I still had that “WTF did I just do” moment. After it was finished however, I had zero regrets.
 

twodogs112

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I have one of the same center channel! Had it for over 20+ years. Still works great. I really like your mod, I might try it when the tweeter dies.
How did you hang your speaker on the wall? Did you use the ml bracket? I’ll be moving my system across the room due to renovation of my living room. Good thing, I’ll be able to bring back my big ml’s out of storage. I’ll be curious to hear what they sound like compared to my clarity’s and Kef 105/2.
My wife thinks I’m nuts with my hi fi stuff. But she has her hobby( salt water aquariums) and I have mine. Thanks.
 

wink

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I have one of the same center channel! Had it for over 20+ years. Still works great. I really like your mod, I might try it when the tweeter dies.
How did you hang your speaker on the wall? Did you use the ml bracket? I’ll be moving my system across the room due to renovation of my living room. Good thing, I’ll be able to bring back my big ml’s out of storage.
Yes, I used the bracket that came with the speaker. Provides the best use and placement for my setup.
What are the big ML’s you speak of?
 

twodogs112

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I have several ml speakers. My first is the aurius . Bought it when they first came out. Purchased to replace my accoustat spectra 1100, which I still have (working by the way). These are the “big” ones!! At least my wife says so!! I also have a pair of clarity‘s. A pair of motion 40 (60) for rear surround with the small motion for presence sound. The original cinema center channel (had for years). A pair of Kef 105/2 in perfect shape (awesome bass) and a pair of Kef 101 wannabes(aristian), beautifull wood with matching stands.
As you can see, I have a lot of equipment and more.
About to start renovating house, so lots of moving around and changes. Wife’s idea, not mine. But that’s ok, celibrating 15 years of marriage today. Happy wife, happy life. How true.
Thanks for the information on your center channel. I’ll have to contact ml and see if they have any wall brackets.
 

wink

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Wow! That’s a lot of storage space being taken up by speakers….Haha! My advice would be to combine all electrostats for a surround system, either the Spectra or the Clarity up front then Aerius or Clarity in rear with the Theater center…..would sound fabulous
Not sure that ML will have wall brackets, but go on USAudiomart and put in a Wanted ad.
 

twodogs112

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Wow , what a great idea. A veritable wall of electrostatic sound. The neighbors would be pissed when I play dark side of the moon with both of my subs cranking!!! Looks like more amps are in my future!
Thanks for the advice. Erik.
 

wink

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Let me know when you put it all together….and don’t forget the pictures when you do!
Dan
 

twodogs112

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Funny, I was thinking about it last night. With the house renovation we might be moving to what is currently the back wall which can accommodate all the speakers. I’ll keep it posted.
 
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