Hi, i'd like to know what you think about the differences between ribbons and amt tweeters.
I want to know about the specific differences, and if you think wich one of the 2 is overall better (if it's possible to say that).
I want to know about the specific differences, and if you think wich one of the 2 is overall better (if it's possible to say that).
I remember when I search for AMT vs RAAL before on thus forum. Many prefer RAAL saying that it is more neutral.
AMT is a very clever way of packaging the magnetic field around the diaphragm. a ribbon should theoretically be better but require a much more powerful magnetic circuit as well as a transformer.
so i would say that AMT for price/performance and ribbon for cost no object ultimate high end.
but this is just theoretically. i don't have any listening experience here.
so i would say that AMT for price/performance and ribbon for cost no object ultimate high end.
but this is just theoretically. i don't have any listening experience here.
The open backed AMT's are bipoles whereas an open backed ribbon would be a dipole.
AMT's are in phase front and back I think, unlike most drivers, including ribbons.
AMT's are in phase front and back I think, unlike most drivers, including ribbons.
Ok, but i find the cheapest amt at 300$. While you the fountek neocd 3.0 can be found for 90$ (it should be an "average" ribbon).
This subject has been covered on this forum before. On one audio half cycle the pleats are compressing air on one side of the diaphragm and rarifying it on the other. For the other half cycle (drive voltage sign reversal) the oposite applies. Thus the AMT is no different to a cone etc, making it a dipole when unenclosed.
AMT's and ribbons share one characteristic in that they are acoustically large in the vertical dimension and small in the horizontal dimension. This means they are going to have broader directivity horizontally than vertically. As an AMT can displace more air than a ribbon for the same motion it can be crossed over at a lower frequency for a given SPL. These are theroretical differences, but like most things in audio the final arbiter is the "earometer"
Keith
Agreed with the above. AMT's also have a higher max power handling and SPL (at least the Beyma TPL-150). AMTs are much less fragile than ribbons. I would note that being able to cross them lower (sometimes much lower) can be very useful if you're concerned about lobing at the crossover and power response.
Two things puzzles me with AMT
One is the front grille
If it was mounted on a dome tweeter or any other kind of driver, noone would buy it
And there would be good arguments why not
The other is less obvious
Its the folding of the diaphragm
Im sure theres lots of things going on in such a folded design
Phase issues maybe, or other nasty things
But it seems the avantages of the AMT are enough to keep in front
Technically, planars with edged coils on the diaphragm should be superiour
But fore whatever reason its not
But maybe it will be, in time
One is the front grille
If it was mounted on a dome tweeter or any other kind of driver, noone would buy it
And there would be good arguments why not
The other is less obvious
Its the folding of the diaphragm
Im sure theres lots of things going on in such a folded design
Phase issues maybe, or other nasty things
But it seems the avantages of the AMT are enough to keep in front
Technically, planars with edged coils on the diaphragm should be superiour
But fore whatever reason its not
But maybe it will be, in time
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ok but the $2 million Transmission Audio system uses ribbons, not AMTs.
what i was trying to say is that AMT is a somewhat practical design, thats why you can find it in prosound appications such as the Beyma driver or Adam Audio studio monitors.
but ribbons are more of a purist thing like vacuum tubes. that is not to say that you can't buy a vacuum tube amp for less than a solid state Krell.
Yep, adam is the reason why i got interested in ribbon tweeters. I didn't know they were amt at first. But i knew that many people who listened to electrostatic hifi speakers say they simply are the best (except for bass). So i believe that ribbons have the same sound quality of the electrostatic. I've also read a lot about adams (as i'm interested in studio sound too), and read many very positive opinions about them.
A custom designer is building a pair of speakers for me, made with seas excel w15ch and fountek neocd 3.0 tweeters. I want to hear the adams, and see how much better the tweeter is.
About raal, i've just read about them too. Many people consider them the best, but i really don't think the price gap between fountek neocd 3.0 (wich i believe has the best price/quality ratio) and the raal is ok. Ofc the bigger raal can be crossed lower, but it costs 5-6 times more...
ribbon performance can vary a lot between models:
http://www.zaphaudio.com/nondomes/
unfortunately Zaph didn't test any high-end ribbons there, but he did prove that cheap ribbons can suck.
i don't know if RAAL is actually better or just more expensive than cheap ribbons but i do know that cheap ribbons have a lot of room for improvement.
of the cheap ribbons Zaph did prefer Fountek as far as i recall.
the way a traditional ribbon is constructed though makes it inherently nonlinear. thats why i had to devise a different technology that i described in other threads.
AMT is theoretically linear but at the expense of a lot of bending in the diaphragm which is likely to have its own effects.
AMT and Ribbons will have different kinds of distortions. therefore it probably will not be possible to say which one is "better".
theoretically AMT should have the advantage at lower frequencies while ribbon have the advantage at higher frequencies. but this may not translate into actual products available on the market because all designers shoot for more or less the same 3 khz crossover point.
a speaker with large AMT for midrange and a small ribbon for tweeter would be a good strategy but there probably aren't any AMTs that would fit the bill ?
Thank you for the link, i'll read it as soon as possible.
Indeed the problem is distortion at the lower frequencies (<3kh). The big raal seems to be perfect in those frequencies. But indeed the price is just too high. 500$ compared to the 90$ for the fountek neocd 3.0 are simpli too much more.
Hope my fountek neocd 3.0 will work excelent with the seas w15ch ^^.
Agree .
In regards to the Fountek tweeters , do they use a transformer for imp matching ?
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All small ribbons tweeters use transformers
Most small (and cheap) planar tweeters dont, because "voicecoil" is edged/laid on the diaphragm
BTW, does anyone have the specs of the oem version of the raal? For example, what's the crossover recommendation? Is it hard to get it for a custom design?
Good question
Im sure some of the people who makes tubeamp transformers could
I once asked a "local" expert, and he told me that he needed the exact impednace of my ribbon foil
Might not be easy to measure, and I expect even very small variations will be multiplied
I had plans to use transformers from some old GAMMA(Decca copy)
But they look a bit dodgy
Here a guy who sell parts fore the famous DECCA
http://hd-audio.orpheusweb.co.uk/price.html
Heres how to DIY
http://home.comcast.net/~hendentures/index_files/Page331.htm
http://www.surplussales.com/Inductors/FerToro/FerToro-3.html
I have neo magnets fore 3 different size ribbons, so its due time I get on with it
Thanks for the info Tinitus .... Sad to have transformer in front of foil ... very sad 
Well get going , I'm already finished with my 3 way and have been frying Amplifiers 😀 separating the pretenders from the real thing..
Pretenders so far :
OCM 200 Pr --- Fail
Eagle 7a - Big fail
Perreaux - Fail
Parasound Halo - Fail ( mono blocs would work )
Worked so far
Krell KSA 200
Adcom 555 ( moderate level )
Adcom 565 Mono Blocs
System is currently Bi-amped and addictive.... 🙂
Well get going , I'm already finished with my 3 way and have been frying Amplifiers 😀 separating the pretenders from the real thing..
Pretenders so far :
OCM 200 Pr --- Fail
Eagle 7a - Big fail
Perreaux - Fail
Parasound Halo - Fail ( mono blocs would work )
Worked so far
Krell KSA 200
Adcom 555 ( moderate level )
Adcom 565 Mono Blocs
System is currently Bi-amped and addictive.... 🙂
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