Klaus,
And anyone else who is looking at and comparing diaphragm materials should be very aware that the diaphragms from TAD are vapor deposited and very different than the material from Brush Wellman's Materion division. The Materion material is made from a beryllium foil and is much stronger than the TAD process though it is heavier in the end.
A very good friend of mine used to work at Radian and also was friendly with Jonas and knew all the players from Radian, Emilar and Renkus. That was a big clash of personalities and that is why we ended up with three companies with nearly identical products in the first place.
And anyone else who is looking at and comparing diaphragm materials should be very aware that the diaphragms from TAD are vapor deposited and very different than the material from Brush Wellman's Materion division. The Materion material is made from a beryllium foil and is much stronger than the TAD process though it is heavier in the end.
A very good friend of mine used to work at Radian and also was friendly with Jonas and knew all the players from Radian, Emilar and Renkus. That was a big clash of personalities and that is why we ended up with three companies with nearly identical products in the first place.
Beaming Is a concern. I may experiment running two of the Yamaha drivers per channel, one on the mid low horn and one in the mid, mid high horn.
Hello Radian,
You have IMHO, more risk to break the diaphragm of a TD2001 on a 600Hz horn than on a 200Hz horn.
Also the suspension of the Yamaha 6681A (of which I am the proud owner of 2 pairs) is a beryllium-bronze made of copper, tin and beryllium and this alloy is not so brittle as pure beryllium is.
I guess that for most endamaged Yamaha 6681A the reason of the endamagement is not in the rupture of the S shaped beryllium-bronze pins but most probably a burned coil.
Best regards from Paris, France
Jean-Michel Le Cléac'h
You have IMHO, more risk to break the diaphragm of a TD2001 on a 600Hz horn than on a 200Hz horn.
Also the suspension of the Yamaha 6681A (of which I am the proud owner of 2 pairs) is a beryllium-bronze made of copper, tin and beryllium and this alloy is not so brittle as pure beryllium is.
I guess that for most endamaged Yamaha 6681A the reason of the endamagement is not in the rupture of the S shaped beryllium-bronze pins but most probably a burned coil.
Best regards from Paris, France
Jean-Michel Le Cléac'h
Hello Jean-Michel,
Thanks for joining our discussion.
Yes I know that people have been running their 6681b to about 250hz and I
think it is totally fine. What I am concerned about is a failure or mistake of
the electronics with a 1st order network in that region.
My drivers had hair cracks but electrically they where fine, so I assume that
the copper/beryllium suspension fails earlier than the coil burns up.
I could be the only one who had this failure but I want to warn people of
risking this wonderful driver. It is just to precious to ruine it by mistake.
As I said before a one horn approach from 250hz to the tweeter is a
compromise IMO. An Atlas Sound PD5V on a Sato or 15A like horn to about
800-1200hz and a small cd like the Seos 12" or tractrix on top will have the
better sonics.
Klaus
Klaus,
I have seen two failures in the 6681b/1401a drivers.
One is detachment from the aluminum dome of the paper VC former (little fingers they are).
The other is burnt voice coils.
I expect that it is entirely possible to fatigue the fingers of the surround. I'd expect that it is a concern. But one has to live dangerously in this audio quest thing, imo.
You can't protect against every source of failure. Of course some people may opt for more safety and security. Nothing wrong with going that way. These are drivers that can not be replaced.
I have yet to find a system with a break in the center of the mids that worked as I would like. There are very good ones, but all in all my view is that it usually ends up being a compromise that I don't like and tends to glare at me due to my particular sensitivities, not visual prejudices (don't care much if it looks good, or conforms to my expectations), I only care how it sounds.
_-_-
I have seen two failures in the 6681b/1401a drivers.
One is detachment from the aluminum dome of the paper VC former (little fingers they are).
The other is burnt voice coils.
I expect that it is entirely possible to fatigue the fingers of the surround. I'd expect that it is a concern. But one has to live dangerously in this audio quest thing, imo.
You can't protect against every source of failure. Of course some people may opt for more safety and security. Nothing wrong with going that way. These are drivers that can not be replaced.
I have yet to find a system with a break in the center of the mids that worked as I would like. There are very good ones, but all in all my view is that it usually ends up being a compromise that I don't like and tends to glare at me due to my particular sensitivities, not visual prejudices (don't care much if it looks good, or conforms to my expectations), I only care how it sounds.
_-_-
Thanks for the historical information about Radian, Emilar, and Renkus. I knew they spun off from Altec sometime in the late Sixties, but I didn't know about the history after that.
Materion/Brush Wellman seems to know beryllium fabrication pretty well, presumably because of experience in the nuclear and military sector. Looking forward to their diaphragm for the Radian 745Neo.
Radian, you are saying that the horn that Romy uses for his upperbass channel with Fane is not done properly. Would you be some kind to provide more explanations about it? What is problem with this horn and how shall it be changed to meet your approval?
I am building a wooden Goto S150 and a Trio midrange horn for the JA-6681B. Does anyone have any experience with these or other horns with this driver. I am open for suggestions.
I am also thinking about using a Trio Tweeter horn for another pair of JA-6681B. Will have to match the throat angles and diameters ofc.
I am also thinking about using a Trio Tweeter horn for another pair of JA-6681B. Will have to match the throat angles and diameters ofc.
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I guess that will be the effect. I am going for what felt natural with my Trio clone.
I started out with the Trio as a model, and when I got the Beyma CP380/M and the Community M200 drivers, I felt like upgrading for something better and also experiment with other horns. I will not stray too much from the principle behind the Trio. When I ran the Community M200 2" compression drivers too high, it did not sound very good, so a smaller horn on top sound natural to me.
I have also experimented with the TPL-150 AMT driver as a replacement for the Trio's top horn with positive results. They don't fit perfectly with the Radian 750-8 2" compression driver I am using now, but will be an okay compromise if all compression drivers I try fail at producing smooth sound between 2kHz and 7kHz without distortion. It is a less lively but very accurat and for easy listening. Works with waveguide, but now I am running it dipole because it sound nicer.
I use a ribbon driver as supertweeter.
Let me know how the 160Hz horn sound like.
Will hopefully finish my wooden Goto S150 this or next week.
I started out with the Trio as a model, and when I got the Beyma CP380/M and the Community M200 drivers, I felt like upgrading for something better and also experiment with other horns. I will not stray too much from the principle behind the Trio. When I ran the Community M200 2" compression drivers too high, it did not sound very good, so a smaller horn on top sound natural to me.
I have also experimented with the TPL-150 AMT driver as a replacement for the Trio's top horn with positive results. They don't fit perfectly with the Radian 750-8 2" compression driver I am using now, but will be an okay compromise if all compression drivers I try fail at producing smooth sound between 2kHz and 7kHz without distortion. It is a less lively but very accurat and for easy listening. Works with waveguide, but now I am running it dipole because it sound nicer.
I use a ribbon driver as supertweeter.
Let me know how the 160Hz horn sound like.
Will hopefully finish my wooden Goto S150 this or next week.
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The JA 6681B has a 1.4 inch exit, but is really a 1 inch exit, with a 14 degree exit angle. For use as a mid high horn it may be worthwhile experimenting with redesigning of the throat to reduce the 14 degree exit, with the new horn beginning at the mesh screen.
BTW i have two pair and will be conducting a very similar experiment
BTW i have two pair and will be conducting a very similar experiment
Okay, cool. I was thinking about it, but I have not seen them yet, and don't know if I dare to dismantle them the first thing I do. The metal throat extension is probably part of what make it sound so nice. I could go with a slow opening GOTO drivere here as well, to match the Goto S150 horn better.
For a vintage Western Electric sound. I like it. It will probably not be perfect, but it will sound very special. I think fast opening horns sound too blunt, if you know what I mean. I was a little dissappointed at this one: http://www.loudspeakersplus.com/product/PH4530/P-AUDIOPH4530/ Though I have not heard the Avantgarde Trio midhorn yet, I fear it will sound very similar. Therefor I am focusing on the Goto now. It is anything but fast with its 135-150cm depth.
For a vintage Western Electric sound. I like it.
It will probably not be perfect, but it will sound very special. I think fast opening horns sound too blunt, if you know what I mean. I was a little dissappointed at this one: http://www.loudspeakersplus.com/product/PH4530/P-AUDIOPH4530/ Though I have not heard the Avantgarde Trio midhorn yet, I fear it will sound very similar. Therefor I am focusing on the Goto now. It is anything but fast with its 135-150cm depth.
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No, my time is limited. I can only build one horn at a time. You mean the 340Hz? I think a 30-40cm deep horn is a too short for the 2" Community M200 and the 2" Radian 750-8, that I have heard so far.
Yes, the 1" and 2" compression drivers I have tried have sounded harsh at times, but that was not what I meant with blunt. With blunt I mean my perception of the sound not being focused enough. I think if I make a horn that opens slower I will get a sound with more energy (almost liquid?). It is hard to explain.
I have sort of given up on making my compression drivers sound smooth with any kind of material I feed them. Netflix movies and metal music will never go together with horn speakers. So I do not plan to make the best allround speakers of all time. I am now looking for a cool horn effect, extreme detail and tube amp sound, while listening to music suitable for horns.
BTW, the best allround speaker of all time for bad recordings would be a subwoofer+midbass AMT+ribbon tweeter, for sure. AMT drivers are the lazy sound engineers deliverance from sin.
You mean the 340Hz? I think a 30-40cm deep horn is a too short for the 2" Community M200 and the 2" Radian 750-8, that I have heard so far. Yes, the 1" and 2" compression drivers I have tried have sounded harsh at times, but that was not what I meant with blunt. With blunt I mean my perception of the sound not being focused enough. I think if I make a horn that opens slower I will get a sound with more energy (almost liquid?). It is hard to explain.
I have sort of given up on making my compression drivers sound smooth with any kind of material I feed them. Netflix movies and metal music will never go together with horn speakers. So I do not plan to make the best allround speakers of all time. I am now looking for a cool horn effect, extreme detail and tube amp sound, while listening to music suitable for horns.
BTW, the best allround speaker of all time for bad recordings would be a subwoofer+midbass AMT+ribbon tweeter, for sure.
AMT drivers are the lazy sound engineers deliverance from sin.
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Quote: I think if I make a horn that opens slower I will get a sound with more energy (almost liquid?). It is hard to explain.
not hard to explain easy. if you have a long slowly expanding horn like an exponential and you compare that to a conical horn with a flare that opens up quickly you will find that the exponential sounds less natural and that it is more distorted compared to the conical expansion. now you may very well prefer the sound of the exponential but that does not change the facts. strange that you cannot get your comp drivers to sound smooth? I expect that you may be doing things wrong. best regards Moray James.
not hard to explain easy. if you have a long slowly expanding horn like an exponential and you compare that to a conical horn with a flare that opens up quickly you will find that the exponential sounds less natural and that it is more distorted compared to the conical expansion. now you may very well prefer the sound of the exponential but that does not change the facts. strange that you cannot get your comp drivers to sound smooth? I expect that you may be doing things wrong. best regards Moray James.
Sorry I have not checked this thread for a while.
I had a drawing done in 2010 for a discussion in the Analog Forum.
It was very crude but I show it anyway. The widest part of the phase
plug should be at the edge surround of the cone and not like in the
drawing that shows it above that point.
Starting at the pole piece of the speaker a phase plug should be
progressively open up, following the contour of the membrane. I would start
at about 3mm clearance to the cone at the pole piece and try to end at
the edge surround between about 8-15mm. Of course this depends on the desired
compression ratio and the size of the cone.
This way the compression happens almost like in a WE555 driver.
In my opinion this is the most important feature in the WE555 that makes
it sound so natural. If one would envision a fluid being compressed in a
normal compression driver vs. the WE555 it would be clear what was the more
natural and smooth way.
With a cone speaker it is not any different.
To cover a third to halve of a cone with a flat piece of board is IMO not wise and far away
from optimized airflow. Great care is taken in a hf horn to find the best contour and good
throat transition and when it comes to low frequency reproduction we seem to forget everything.
As if the laws of physics do not matter as much at those frequencies.
At the moment I have no time to write my thoughts about the subject in more detail so this has to
do.
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