I picked up a set of Diamante's for cheap. They have trashed foam surrounds but otherwise seem fine. I plan on veneering the "marble" with a beautiful teak or rosewood- I haven't decided.The angles will look pretty cool with the right veneer. The marble is not so cool but rigid and heavy.
Curious if some upgraded drivers would improve the sound- as apposed to re-foaming. I realize this is a shot in the dark but my understanding is Roy from GMA has passed so not sure where to get driver advice. Open to any and all suggestions.
Carpathian, if you are curious, I probably would not have been as eager to restore had I even passingly considered the issues I would be facing. But now that I am in… no quitting.
And if anyone else is considering veneering over cultured marble with a variety of angles……… I wouldn’t recommend it. I have found a successful process, but it is a pain. I intentionally have let them set for a few months to see if the adherence is stable. Even the speaker cut-outs have no wiggle room so after veneering them I had to slightly turn down the holding rings by 1/32”
What I would love to do but won’t, is cut the top 4 inches of the speaker off, the obelisk, and make it flat. Veneering those is an absolute bear. I had every finger bandaged from razor cuts on the first one. The reason I didn’t start the second was I am rethinking the process to possibly find an easier but aesthetically attractive approach.
i won’t do anything beyond the veneering and surrounds until I listen for a bit. I will look things over on the cover to make sure no leaking caps but otherwise no immediate changes. I have a decent number of high end caps in my tool box so at some point I might tinker but I would make sure the existing unites were mapped and saved for reinsertion.
As a previous owner of GMA speakers I would suggest you finish your cosmetic work and then spend some time listening before messing with the crossovers. While yes to a point Roy had to parts source to a price point he also parts sourced to a voicing he thought was correct for his designs. Following the advice of Kenjit and others and making wholesale changes and upgrades may result in nothing more than an unlistenable speaker with premium parts. I would trust Roy's judgement over the "self appointed" experts. But feel free to trust whoever you choose.
Before you consider changing anything in the crossover, decide if you like them the way they sound. The crossovers are simple looking because they were first order and will have a minimum number of parts. Messing with the crossover could make matters significantly worse.
Make sure you upgrade those crossovers in there as they were using quite basic and cheap circuits to save money. You might need to use an active crossover
Nope. I have 1 veneered. It got pretty frosty and my barn isn’t heated. I also got distracted with a zillion other things. I am committed to completing. I do appreciate your continued curiosity.
I will figure out how to post some pics when I finish and let everyone know how they sound. Small delay as I am working on some other projects temporarily- namely a motorbike for the grandson. One speaker has been fully veneered and looks pretty good. The metal covers are now a little large so I need to spin them down on the lathe.
No idea. I haven’t mounted the drivers due to the veneering project. All the dang angles on these things have me slicing my fingers up with razors as I trim the veneer. Veneering box speakers is a breeze. Marble geometric, not so much 😉 Another few weeks and we will fire them up with both tubes and solid state to see which sounds best. Thanks for the inquiry.
Thanks for asking. I have all the drivers rebuilt. I also have the wire grills reshaped. Just tonight I veneered one of the speakers with an exotic grey walnut. To say it was a challenge would be an understatement with all the angles. I don’t know how to post pics or I would. I will attempt to send you one directly.
So for those willing to attempt a replacement of a surround; It wasn't bad. If you remove the dust cap you can shim the voice coil so it is centered. I would recommend practicing putting your glue on some scrap first and understanding its working time and any idiosyncrasies. The first speaker the glue tube had some gel in the top and made a bit of a mess. Took some effort to clean it off. Some videos suggest using a brush to spread it evenly on the surround- I found my finger was far superior to avoid mess. Overall, the Eton mid- ranges tuned out pretty great. Still awaiting the ScanSpeak surrounds.
I had a pair of the first run Diamantés with solid black bases and the dark green swirled uppers. I liked the appearance of them. I toured the factory in Colorado Springs and spoke with Roy prior to purchasing them. The speakers have a live sound and excellent reproduction of dynamics. They were definitely not a warm sounding speaker in my setup. More of a sit up and listen presentation than a sit back and relax.
I used OCOS speaker cables with the snap connector ends which greatly simplified installing the uppers onto the bases. Routing speaker cables through the bases and trying to pull back the excess cable whilst placing the uppers on the bases was a PIA for one person.
Amplification at the time was a Classe DR5 preamp and a pair of Classe DR8 amplifiers.
You might want to look to see if yours have some of the updates. The first one, and one that made the most significant improvement was the addition of C channel aluminum braces which were bonded to the lower sides of the cabinet in the woofer section. As I recall the braces were composed of two per side, four for each speaker and bonded with construction adhesive. The instructions also stated to remove approximately 18 inches of the wool from the transmission line. I did the install myself. Later on there was an upgraded crossover, Series 3? which mellowed the speaker. I didn’t like the crossover upgrade and eventually sold the speakers. I don’t recall how one would identify which crossover is which.
Appreciate the recommendations. leather may be a good choice but I am familiar with veneering techniques and a Rosewood or straight grained teak might be just the ticket for these. I also thought about veneer that has a pronounced heartwood color that could be centered down the front bevels. We shall see. The foam surrounds are a full 203CM/8" so most aftermarkets wont work. Ordered originals which take a bit to receive.
I never met him but have never seen anyone post that he was anything but a true genius and a really nice guy. I saw these in a local ad and couldn’t believe a pair would be tucked away in the middle of nowhere. They were not in the hands of an audiophile. Covered in dog hair and dust, and by nature not very attractive, they were a sorry lot. They will come back to life and stay in the family collection. I don’t like to see vintage high end go to the trash or destroyed.
I would also agree to refoam and not try and replace the drivers. I know Roy would also for some drivers write - , 0 , or + on the back of the drivers as he would then match the drivers and only include the same matched drivers that he individually tested. So for instance both tweeters would have the marking - on them not - and then +.
I've owned the Europas, Callistos, Eos HX and C1.5 and they were all excellent speakers. I still have the Callistos and spare woofers for them. I've since upgraded to full range speakers but the midrange, detail, soundstaging and realism of the Green Mountains was first rate. I also enjoyed speaking with Roy on many occasions although I really didn't understand all the physics. I always felt like I just had a one hour physics class when the call ended. He was such a great, knowledgeable guy. I was in line to get the EOS ribbon tweeter model but unfortunately that never happened.
Roy would dumb things down so that i could understand what the hell he was talking about. in the end it was all academic, its how they sounded that counted. wished he had quit smoking.
Your friend is spot on in many of the discussions I have seen. This one has been refreshingly civil- maybe I should bring up fuses or wire 😉. I have been able to order replacement surrounds and even the tweeter silk dome. Should take a few weeks to all come in and I will update. I asked a local cultured marble place for some scraps to experiment on veneering techniques as well. And DeKay…. I hit the jackpot on the marriage front.
Here is a reply from my friend who owns a couple pair of Green Mountain speakers and knew Roy well. He is very technical, basically an engineer:
I've found over the years that people don't want advice in audio forums.
I'm staying clear of them all.
People used to argue with Roy, who was a Physicist, about speaker design.
None of them ever won the argument, but some kept trying.
Tell them anything and you're an audio snob.
Between you and me, I doubt any "updated" drivers would work, as Roy used 1st order crossovers in all his designs, meaning the woofer had to play higher and the tweeter lower.
Dekay, I saw that link as well. I have the drivers pulled and awaiting some feedback from Madisound. ScanSpeak was quick to respond but not much help. My wife is gagging over the look of these things :-0
I appreciate everyone's input thus far. Truly helpful and welcome.
My speakers use all scanspeak drivers. It is really quite a blessing to be able to buy them off the shelf from Madisound when needed.
I’ll mention that while the main speaker ID numbers remain the same, scanspeak will sometimes add a suffix that will indicate the latest iteration of the driver.
The mid woofers I have purchased over many years have a different suffix that has changed a couple of times over the years and indicate there are slight changes in the manufacture of the woofer. As an example, the latest I purchased have a slightly larger surround than the previous. I believe all the speaker sound characteristics remain constant, I don’t notice a difference in their sound profile.
A local dealer has drivers re-foamed all the time. He has a tech that can do it, but, it takes the tech hours to do a pair, while the place they use charges $50 to do the job. The commercial operations can even do extremely delicate work, like replacing the surround on Lowther drivers, some can re-cone and replace spiders.
My buddy Dale was friends with Roy, who did pass on. Dale knows a TON about Green Mountain Audio products and I sent him the link to this thread. Before you do anything wait to see if he has any advice.
Most bigger cities that I know of have PROFESSIONALs that are skilled at rebuilding drivers—everything from new surrounds to new cones and even coils. This might not be the exact same quality speaker that was in it originally when you are done but you actually take the chance on improving them with new modern materials and compounds being used. Do your research first and even get references. You might want to go the extra 100 miles to get a better tech to do the right job.
Congrats on the speakers. Over the years I owned Imagos, Callistos and Continuum C3. All were excellent performers. Roy was a true genius in my book and a real gentleman.
It isn’t really marble. It is a synthetic resin. I figured I would practice different techniques on the underside and see what sticks best. The material is very similar to cultured marble shower walls. I believe if roughed up it will hold. I generative titebond on both substrates, allow to dry, and then reactivate with an iron. I prefer this over contact cement as you can adjust for fit.
Speaking as a woodworker, veneering marble isn’t that straightforward. Since you are only doing one side, and since the affects of environment on marble and wood are very different, choose wisely and test. A self-balanced veneer - two sheets stacked in opposite directions - is more stable than a raw veneer. A paper backed veneer is even more stable. Marble is a strange product with adhesives - so contact cement may be out. I use heat lock - but have no idea how it would work with the marble.
Contact Scanspeak, give them the model #s and see if they have any or if there’s a very similar or maybe even improved version. Start by going to the source.
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