Paul, these shorts are an incredible legacy of your irreplaceable knowledge and experience. So great that you are archiving this. Can’t thank you enough. For our future.Hank
I bought a vintage pair of ESS AMT-3 Rock Monitors and a Sansui Eight Deluxe receiver at an estate sale. There was also a Nakamichi cassette deck, and another piece of gear and I won the whole lot for $25! Everything was in perfect condition and the woofers had new rubber surrounds. I added a 450-watt RMS per channel power amp (A/B) and a 12" JBL subwoofer. Absolutely the best find/bargain in my life and I now have the 1974 system that I could not afford back then when I was a 14-year-old budding audiophile!
Well said! I’ve been an audiophile for fifty years and even owned the original ESS AMT 1A speakers, but your simple definition of the difference was awesome! Thanks.
I enjoy learning technical things and the techniques employed in what makes it all go. Paul you sure do know how to put it all in a very defined and understandable & entertaining way. 👍👍
As an owner of a pair of ESS AMTs,.......what a great video. I had never seen a more descriptive video of how the AMT midrange/tweeter works. I still marvel at the transparent and live sound that these "multi-directional" speakers emit. I (sadly) at the end of my stereophile existence (75 this week), so I won't be trading and upgrading equipment any more.....but rest assured...If I was to trade in my ESS EMts for another pair of speakers.....your models would be first on my list. Bless you for ALL your great videos (in spite of the fact that you hate bass and treble controls...hahaha)
I built a pair of speakers using Decca-Kelly ribbons back in the '60s. They had the best treble I had ever heard. A party piece was to place a wine glass on a speaker which would shatter when a woman sang at a high pitch. After emigrating, I was stuck with cone speakers for a few years, but then got a pair of Maggies which I have now had for 40 years and am very fond of (re-paneled twice by Magnapan). The lack of distortion means I can listen to them for hours. Yes I added a REL sub and would encourage other owners to try one as they really add body to the sound. I convinced one acquaintance by demonstrating a soprano singing a solo, with and without the sub. Why would a soprano need a sub? Well try it and you may be astonished by the difference.
I had the ESS AMT-1Bs with the full size Heils, that had an Omnidirectional mid to high Frequency Range soundstage that no other speaker has today. It's sound presence is airy and remarkable. I auditioned Planar Ribbons and they are no comparison!
One of the best things about an AMT tweeter is that the diaphragm can be replaced easily in only a few minutes. Remove two screws, lift off the top plate, draw out the blown assembly, detach two wires. Reverse the steps with the new diaphragm. And, if I remember right (don't count on that), the diaphragm was relatively low-priced, maybe $10, in 1980.
I've had a pair of Infinity Gama's for about 20 years and recently bought some new speakers with Beryllium tweeters. The new speakers are amazing but missing the texture of ribbons. For me it's the sound that I got used to. Im not a speaker expert but I will be changing the Beryllium to ribbons. And hopefully be satisfied.
Jack Smiley was an engineer at ESS, and until a few years ago, he used to make AMT's that crossover at 500 Hz. The guy who built my speakers was his main customer, and I have a 5.2 system based on them. Taking the AMT's dynamism down to the mids is amazing. I appreciate planars for not being tiny little domes, but their lack of athleticism always leaves me wanting.
I just realized Chris designed planar tweeters at BG Radia corp (ex Bohlender Graebener). The PS Audio loudspeakers use the same kind of planar tweeters BG were producing. They look exactly the same. Now, BG went under when the owner died but their supplying factory in the Philippines didn't. Problem is: that Philippines factory QC seems to be very poor. So my guess is that PS bought a bunch of those drivers and is doing proper QC in the US and discarding tons of them.
So an AMT tweeter has more dynamics but has more top end distortion. A planar tweeter doesn’t have the same dynamics but a lot less distortion due to the lighter than air material. A dome tweeter is heavier than air so there is more distortion due to its inability to instantly stop.
Can almost describe the AMT's as linear arrays as each pleat is acting as its own driver, but they are all attached to a common motor instead of separate motors. It might be interesting to build some "new" (custom) ones using a mylar substrate and aluminum oxide (or some other material) deposition onto the substrate to make them even lighter in structure and maybe a few design tweaks to the motor to keep the full coil in the guass field (having trouble finding diagram of how they are made so maybe thats not an issue, but very few speakers do this and its a typical weak spot).
I have a pair of ESS Rock Monitor II Limited Edition with 2 6" woofers and a small (half size?) Heil driver. I absolutely love them. Sadly ESS is only making parts and 1 speaker these days. The AMT 1D Revival.
Great example & explanation Paul, thanks! So, with the fact that the material is so thin and it is vibrating to move all that air, is there a worry that the material will wear out and the tweeter will need to be replaced regularly?
Still have my original ESS AMTs but they got relegated to my TV room when my music room got a pair of used Quad electrostatics about 20 years ago. Both sets of speakers still work although I expect the Quads to fail eventually. Tried to get them rebuilt about 4 years ago and was told they are now too old to repair. Maybe Paul will sell me just the top pair of planar tweeters to combine with existing speakers when the quads finally die.
If memory serves, which it does less each day,... the EMITs were relatively fragile as well? Tending to get fried likely from clipping the amp to drive them?
Thanks for your explanation. The law of physics says F = M * a So less mass is better to get the right acceleration, but what if you can raise the force? Yes it is more difficult to create this force without creating heat, but how do you create the required stiffness for your driver without adding mass? (and still keep the longevity for this driver? The -problems- challenges of an engineer i guess.
"Planar ribbon" is just a confusing term. The way Paul uses it then every flat panel is a ribbon. Here is a workable definition of a _ribbon_ (when it comes to transducers): a laminar object that is *attached to a baffle on **_at most_** two sides_ and nothing else* . Additionally, for the purposes of audio reproduction, *a ribbon is much longer than it is wide, so that it acts more like a line source for a sound wave.* A _planar_ transducer, such as what Paul is holding appears to be like the large transducer on Magnepan (and Clarisys and electrostatic panels, etc.) Such planes do not act like a line source because of the dimensions of the laminar material. What Paul is holding seems much more like the Magnepan marketing term _quasi-ribbon_ , which itself is more about marketing than describing how the transducer actually makes sound.
Yes typically a ribbon's magnetic structure is along the edges and the ribbon is the conductor. While a planar has the magnetic structure as a parallel plane in front and/or back with the conductor attached to a flexible membrane and holes in the magnetic panels for the sound to pass through.
It’s not a secret, states on their website that its made of teonex. He mentioned Kapton which is what a lot of planar drivers use for its temperature tolerance, which is higher than teonex. Maybe Teonex has some damping qualities that is desirable or perhaps it’s just because it’s cheaper… or both. Check the IRS Epsilon white paper for some information on diaphragm material and challenges with damping, etc. Haven’t seen a better write up for that subject.
