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post #421 of 1530

The Stax SRD series is indeed what you would find in the base of electrostatic speakers scaled down. Transformers to take the single ended input and phase split it plus providing massive voltage stepup and a small power supply to polarize the diaphragm. 

post #422 of 1530
Kevin and spritz beat me to it!

But yeah, ES speakers have transformers or (in the case of a few MartinLogan models that come to mind) complete amplifiers built in. They still need a bias supply and all of that, even if they're "passive."

Magnepans aren't stats. They're also not (to my understanding) truly planar magnetics either - they have a unique (inasmuch as it's patented and they defend it) orientation that differs from a conventional planar magnetic (e.g. Eminent) or ribbon (e.g. Bohlender) and other designs (e.g. AMT) - they're sort of a ribbon and sort of a PM. Magnepan calls it a "quasi-ribbon driver" - it uses mylar like an ESP, but a magnetic strip like a PM or ribbon. They're very different internally from something like a MartinLogan Aeon or Quad ESL - that's for sure.

The end result though is fairly similar - they all produce a planar radiation pattern and are true dipoles, so keep both of those in mind when placing (as both MartinLogan and Magnepan will tell you - pull them out from the wall, toe them in, tilt them slightly, etc).
Edited by obobskivich - 9/4/12 at 11:05am
post #423 of 1530

Thanks to Kevin, Spritzer and Obo for explaining that to me - I see a thin, wafer-like design and leap to the conclusion that its electrostatic. When I look at MartinLogan alongside Magnepan. its obviously not quite the same thing, but as I said I havent had much interest in unconventional designs prior to the buzz created by the Mini Maggies. Color me embarrassed but a few percent wiser.  wink.gif

 

 

 

post #424 of 1530
If it helps your understanding any, the Magnepan speakers have more in common with HiFiMan headphones than Koss ESPs (still not quite the same though). From a functional perspective, you can treat them all roughly the same, as they're all planar dipoles. smily_headphones1.gif
post #425 of 1530

I think some Maggies (1.7 and up?) are actually true ribbons

post #426 of 1530
Quote:
Originally Posted by n3rdling View Post

I think some Maggies (1.7 and up?) are actually true ribbons

1.7 is a "Quasi-Ribbon" according to Magnepan. They're vague on the 3.7, on one hand I see "Quasi-Ribbon" but on the other I see "True Ribbon" (both of these are Magnepan terms) like the 20.7. I don't think any of their speakers are truly analogous to what you'd find if you ripped a BG apart though. redface.gif
post #427 of 1530

Whatever it is it sounds fantastic.

 

Quote:
Originally Posted by obobskivich View Post


1.7 is a "Quasi-Ribbon" according to Magnepan. They're vague on the 3.7, on one hand I see "Quasi-Ribbon" but on the other I see "True Ribbon" (both of these are Magnepan terms) like the 20.7. I don't think any of their speakers are truly analogous to what you'd find if you ripped a BG apart though. redface.gif
post #428 of 1530
Thread Starter 
Quote:
Originally Posted by obobskivich View Post


1.7 is a "Quasi-Ribbon" according to Magnepan. They're vague on the 3.7, on one hand I see "Quasi-Ribbon" but on the other I see "True Ribbon" (both of these are Magnepan terms) like the 20.7. I don't think any of their speakers are truly analogous to what you'd find if you ripped a BG apart though. redface.gif

I have a pair of Magneplanar 3.6's, and they do, indeed, have a 'true' ribbon tweeter. So do the 3.7, the 20-series, the "Mini Magneplanar" and a few other of their speakers.  In the 3.5, 3.6 and 3.7, the tweeter is a 6-foot-long (or is it 5 feet?) pleated piece of aluminum foil hung in a strong magnetic field.  Just a very thin piece of foil, through which you run your treble signal.  2.9 ohms.  There are tiny dots ( 1/64 inch or so) of silicone adhesive along the edge between the foil and the magnets along the sides, about every 8 inches.  These are apparently to keep the diaphragm from getting stretched out easily- they tie the diaphragm to the frame of the tweeter, but since the foil is pleated it is still quite free to vibrate.  These little "suspension dots" are hard to see.  I think Magnepan has a patent on this aspect of the tweeter. 

 

Here's a company that rebuilds Magneplanar tweeters for folks in South Africa, where I suppose it's difficult or costly to use the "exchange replacement" service that Magnepan offers. On their website you can see pictures of the tweeter as it appears on it's own, removed from the speaker "panel" http://www.celestialsounds.co.za/magnepan-ribbon-rebuild/ .  The tweeter can be damaged by WAY too much power, DC, or other failures of judgement or equipment. In my system, which is tri-amped, the tweeters are driven directly by a Nirvana Electronic Works  class-A amplifier.  If the amp's output stage ever failed and sent DC through the tweeter, I imagine the diaphragm would melt until a spot burned all the through and opened the circuit. There's a fuse, but the Semmelheinz corollary of Murphy's Law states that the expensive tweeter diaphragm will open first, saving the 50-cent fuse from damage. If that were ever to happen, one just packs the tweeters off to Magnepan in Minneapolis, and they send a new pair for something like $300.  They're very clever, those Magnepan folks. To protect the tweeter in shipping- either when installed in the speaker or when being mailed as a replacement part- they use a 5 foot long piece of steel banding tape- the stuff that is used to secure items to shipping pallets.  The magnets just hold the steel tape in place firmly, making a very good "shipping cover" for the tweeter.

 

Here's a picture of the tweeter as it is installed in the speaker, as viewed from the back- that's the tweeter on the right....

 

 

 

 

The midrange and woofer drivers in Magneplanar's ribbon-equipped models are actual 'planar magnetic'  drivers, which conductors bonded to a plastic film, suspended in a magnetic field. The tweeters in ribbon-equipped models are just thin aluminum foil, no plastic film "base."

 

Not all Magneplanars use ribbon tweeters. The Magneplanar models that use "quasi-ribbon" tweeters have conductors bonded to a plastic film for the highs just like the MG 3.6's midrange and woofer panels.  In fact, the MG 3.6's midrange panel is flat to about 18,000 Hz and only down 3 dB or so at 20,000. It would be prefectly useable as a tweeter- but the "true ribbon" has a lower moving mass, is MUCH narrower which improves horizontal dispersion, and so on.  The ribbon is a better treble driver.

 

Just all FYI.

post #429 of 1530
milosz,

As always - you're the man. Thanks for the explanations! biggrin.gif
post #430 of 1530

Sorry I am late to this but a few pages back some one was mentioning squeal in their pair.  I don't know if this makes sense but if you leave them plugged in overnight and on (doesn't have to be playing anything) does the squeal seem to go away? 

post #431 of 1530

Not if there's mice in them...........just sayin.wink_face.gif

post #432 of 1530
Quote:
Originally Posted by livewire View Post

Not if there's mice in them...........just sayin.wink_face.gif

So does this somehow imply that Koss headphones are better than STAX for attracting household pests? tongue.gif
post #433 of 1530
Quote:
Originally Posted by obobskivich View Post


So does this somehow imply that Koss headphones are better than STAX for attracting household pests? tongue.gif

 

No, STAX is definitely the winner here..........http://www.q-audio.com/antsinstax.mov

post #434 of 1530
Quote:
Originally Posted by WilCox View Post

No, STAX is definitely the winner here..........http://www.q-audio.com/antsinstax.mov

Glad someone else got that one...biggrin.gif

But c'mon, MICE are worse than ANTS.
post #435 of 1530

Disagree. If you had mice in your headphones you could easily take them out. Ants...not so much.

 

Quote:
Originally Posted by obobskivich View Post


Glad someone else got that one...biggrin.gif
But c'mon, MICE are worse than ANTS.
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