Why is there not at least a 6” BE midrange? Is it too brittle? What about beryllium formers? Apparently it had amazing temperature related properties? Is it magnetically inert enough? The BE former could theoretically be literally part of the BE dome or cone (shape and contours and thickness is also important but there’s a company in LA called LA Guage that has extremely impressive abilities to mill it and a thin dome with any thickness and an extremely thin former could probably also be worked out but those are so thin i’m not sure if humans can machine .001mm or whatever it is either way as a number of stiffened foils which must be possible, this could change things what’s going on? I know how lethal it can be but this clip shows some great promise
I’m aware of Paradigm and TAD concentric i’m just surprised that this is all I can find aside from Compression drivers
Basically is there anything preventing a company like Bliesma or Scan Speak from making a 6” BE driver. Scan Speak would put up the money, Bliesma seems like a game changer but i’ve yet to hear them. A 6” Similar to the M74B? They haven’t made a basket woofer type yet but they must have plans that would be the next next step.
And also why not use it as a Former it doesn’t change properties basically at all from extreme temperature changes, is lighter than titanium, stiffer, better damped. Just seeing what the furniture may hold.
I think the main questions are to what end and at what cost. Ceramic diaphragms, diamond diaphragms, whatever, are all possible and used here and there, but they all have their own issues - whether that's cost, new processes that have to be debugged, requiring new material characterization, nasty breakup modes some people don't like, etc. As you indicated, beryllium also has health hazards. Working in a bunny suit/cleanroom is its own joy on top of the large costs involved.
And then there's this interpretation of the situation from B&W on tweeters, at least:
https://www.stereophile.com/news/112204bw/index.html
"Most notable is the incorporation of a diamond diaphragm for the tweeter of the top units in the line, in place of the aluminum dome used in the past. This material was employed after Finite Element Analysis (FEA) indicated that the physical properties of other exotic materials, such as titanium and beryllium, did not offer significant advantages for audio performance despite being, variously, stiffer and/or less dense than aluminum."
And then there's this interpretation of the situation from B&W on tweeters, at least:
https://www.stereophile.com/news/112204bw/index.html
"Most notable is the incorporation of a diamond diaphragm for the tweeter of the top units in the line, in place of the aluminum dome used in the past. This material was employed after Finite Element Analysis (FEA) indicated that the physical properties of other exotic materials, such as titanium and beryllium, did not offer significant advantages for audio performance despite being, variously, stiffer and/or less dense than aluminum."
I've read that beryllium foil is very difficult to work with when it comes to shaping/forming. Also if any machining is done then the health hazard of the dust created is especially challenging to deal with. This is why audio companies often go with the Chemical Vapor Deposition approach when it comes to forming small and thin structures from beryllium.
So for something like a 6" midbass with a pure beryllium cone, I think it's probably just a cost vs performance vs fragility thing that prevents it from happening. Same with diamond diaphragms and why there seems to be a maximum size that they are made up to.
So for something like a 6" midbass with a pure beryllium cone, I think it's probably just a cost vs performance vs fragility thing that prevents it from happening. Same with diamond diaphragms and why there seems to be a maximum size that they are made up to.
Also it's interesting that when Yamaha released the NS-5000 in 2019 they went with Zylon synthetic material instead of beryllium like with the old NS-1000: https://usa.yamaha.com/products/audio_visual/speaker_systems/ns-5000/index.html
I had seen a little youtube tour around a facility in souther california that is now able, no hands being used but to type buttons, to machine some VERY intricate pieces which were to be used to “a high level legendary space agency. It was one of those put a billet in, seal everything shut and watch the robotic blasting/laser thing just doing so easily something that must me tenfold more difficult than the 6” or even 4”-5” diaphragm. I tried posting the links but apparently i’m too new still on here at this point to get a 3-5min uploaded youtube video to be placed in my thread. Long story short I fully respect your answers, as of now the questions I have deal more with theoretical and physical implementation with very little to no Elexteocal engineering knowledge. As I have said before my father does have fairly in depth knowledge of EE, which is what i’m gonna call it now. He opened; completely setup(his own mic pre’s, HUGE consoles and quite a few swiss made (brand names should be treaded on lightly in this forum as I’ve come to understand. He was doing fully mastered and completed Digital Recordings a matter of months before Berklee was.
One interesting tid bit, as he did many many of the demos and some singles or however it was done between 77-91 In the Boston area, and before that at UMASS Amhearst in 68- very early 70s, his acclaimed for quality short on cash studio Sound Techniques, in case anyone was curious, was located in Watertown MA. At the exact same time Boston was recording their self titled album also in Watertown, MA (4 sq miles large) and Leon (my father) knew Tom Schulz fairly well. I was not aware Schultz was far more than middle of his class electrical engineer (or a field of study very similar at MIT a few years before. What had taken Leon Janikian, again my father, a matter of 3-3.5 years to be getting some very hi end recordings on demos (the small records?) Schultz was not only able to use completely proprietary experimental techniques, but the final recording for that bazillion ( last I checked around 20+ million copies of the “boston” album was done from schultz from A to Z. Schultz like my father did a good amount of literally 7-10 blocks away still in Watertown and they used to hang out all the time. A little bird told me they Mr. Schultzs goal was to play everything he could in almost literally the exact way it was cut on the record, something which both myself Aaron J and Leon J (papa duke’s) who are both berklee and NEC “people” find it nearly impossible to come up with, love it or hate it, such music without being improvised at many points. Schultz always denied this to my father and would imply more or less that he didn’t need to hear it. I can assure you there are no pieces of either brilliant or not so brilliant pieces of music ever written without the use of ears and later in Beethoven life his muscles memory worked fine. He knew exactly what ode to joy sounded like. Very long point in being is that musicians learn using all ears and muscle memory. So he may have been a genius’s in many ways, he did not come up with those some ears some sight writing/reading
Not to be misunderstood, it is one of those albums where I can listen and listen without any tracks that make me want to smash the LP or should I say CD better yet great DSD.
While it's certainly do-able to machine thin beryllium cones and domes from billet, that's the least cost effective way possible to do it. You'd be spending expensive machining time to turn 99% of an expensive cylinder of metal into highly hazardous dust. Not to mention the fragility of the thin sections and the challenges of trying to hold it.
Also that machining center would be contaminated and would be impossible to sell on the market when it cones time to upgrade.
As a machinist myself there's no doubt in my mind that the CVD process is the way to go for thin beryllium diaphragms. Then you could have the VC former be seamlessly integrated into the cone, you could easy have rib structures on the cone if need be, etc. CVD is an additive process so there's little waste.
Not to mention that you could do diamond diaphragms with the same CVD approach.
Also that machining center would be contaminated and would be impossible to sell on the market when it cones time to upgrade.
As a machinist myself there's no doubt in my mind that the CVD process is the way to go for thin beryllium diaphragms. Then you could have the VC former be seamlessly integrated into the cone, you could easy have rib structures on the cone if need be, etc. CVD is an additive process so there's little waste.
Not to mention that you could do diamond diaphragms with the same CVD approach.
I know this is an audio forum, but I have a question that is musically related. I am a professional drummer and teacher and have drilled my own shells and used OEM Lugs (the metal things that sit on the outside of a drum shell) Would you be able to machine drum lugs. I would want actually a very simple design but preferably brass copper plated or made of brass (aside from the threaded part which must be a harder metal) Having one’s own unique lugs is actually basically seen as the difference between being an amateur builder and having a valid drum “company”. Based on your statement that you could conceivably machine a beryllium dome, I would assume that 10 double sided or 20 single lugs wouldn’t be a stretch and had to ask because i’ve been wondering this for years and would pay up. It is also an opportunity for you to show off your abilities and I would give you freedom to even use your own logo on them if you wanted, or do what you would like within the basic simple cylindrical design I would like to use. I have a few more specific questions but I will leave the questions here my friend. By the way, I don’t use the same Keller Maple shells everyone does. There’s a company I found that makes shells using Bubinga, cherry, walnut, and of course maple and birch as well as some exotics that are very affordable and this would give me the ability to make drums that are very difficult if not impossible (if they are willing to mix plys of different woods in one shell for me) for people to get. Basically they would be unprecedented, aside from the Yamaha PHX kits that aren’t made anymore and maybe two other examples but these shells would be different and I’m not going to try to explain it but the lugs basically create the look of a drum that allows us drummers to recognize one on sight. Let me know man, and while you’re at it i’ll take four accuton 7” super midranges the 168 except with beryllium diaphragms and formers.
Having specs beryllium diaphragms I know the problems. They are $$$&$. A 1" BE diaphragm can be $10. And that's is in volume. Expensive 1" headphone diaphragms are in the $1 range. Also the high q of the material will have difficult resonances in the audio range in larger diameters. There are other options better for midrange applications.
Would you say that ceramics, CF/Graphene, Nomex Core types, as well as good quality paper cones would all be superior? If there’s somewhere I can read up on materials science in loudspeakers, I would just do that but I can’t seem to find anything that isn’t in some way promoting a product.
I know of no dispassionate discussion of cone materials. Only the vendors offer info and of course its about selling. Voice Coil: https://audioxpress.com/page/Voice-Coil-Magazine Is the only other option and its not ideal. Unless you are in an unusual position you really can only get what someone is making already. Totally custom is a major undertaking ($$$).
I assume that making drivers from scratch would put me back possibly at least a million in R & D as well as production and all that crap. I don’t have money like that but I can’t seem to get a definitive answer as to why they use titanium formers as opposed to beryllium ones. There are driver companies who make cost no object stuff, like accuton scan speak Bliesma (who IMO could become groundbreaking and is in the process of doing so. This being said, because of the health risks Accuton won’t deal with BE, and their stuff is some of the most cutting edge performers on the planet.
I just wonder what is possible if I were Elon Musk and were this fascinated with sound. I will be brought to tears by hearing the right piece of music on a hand radio, but I still love the resolution, dynamics and ideally holography as well as the science behind these things. I’m not one of these people who listens to music to hear the system, but rather it is a sort of different fascination. My love for music is not a fascination it is something I was born with and sound quality doesn’t matter a huge amount to me in that regard. I just wonder what a 6” Beryllium Mid with a BE former, and a GREAT motor system designed cleverly and with great detail would sound like. I get the feeling it would be better in every way than what we have, but not that much cleaner.
This being said, we must be moving forward constantly as a society and this applies here as well. Breakthroughs aren’t made unless the current limitations are being pushed on and ideas are tested. There are people out there with the means to make these drivers and experiment with $$$$$ materials and concepts even if simply in the name of pushing the art and science forward.
Apparently BE along with all the known benefits, is particularly inert when faced with drastic temperature increases. At levels as unique as all of its other properties. This begs the question why no BE formers? I may be unaware of something that answers that question, or it is a matter of no one having the initiative to use some of their millions to find out? I don’t know the answer but if anyone does, let me know please.
I just wonder what is possible if I were Elon Musk and were this fascinated with sound. I will be brought to tears by hearing the right piece of music on a hand radio, but I still love the resolution, dynamics and ideally holography as well as the science behind these things. I’m not one of these people who listens to music to hear the system, but rather it is a sort of different fascination. My love for music is not a fascination it is something I was born with and sound quality doesn’t matter a huge amount to me in that regard. I just wonder what a 6” Beryllium Mid with a BE former, and a GREAT motor system designed cleverly and with great detail would sound like. I get the feeling it would be better in every way than what we have, but not that much cleaner.
This being said, we must be moving forward constantly as a society and this applies here as well. Breakthroughs aren’t made unless the current limitations are being pushed on and ideas are tested. There are people out there with the means to make these drivers and experiment with $$$$$ materials and concepts even if simply in the name of pushing the art and science forward.
Apparently BE along with all the known benefits, is particularly inert when faced with drastic temperature increases. At levels as unique as all of its other properties. This begs the question why no BE formers? I may be unaware of something that answers that question, or it is a matter of no one having the initiative to use some of their millions to find out? I don’t know the answer but if anyone does, let me know please.
Also, I know Hedd in Germany is working on a ab AMT midrange and is getting somewhere with it. This to me has HUGE potential. Imagine what a 20hz-20khz all AMT system could be? Getting below probably 400hz won’t happen for a long time with AMT but getting down there IMO will happen within 5 years and I cannot wait for that. The Hedd headphones use two distinct pleat patterns one of which digs down and they are the only headphones aside from a select few that sound somewhere near a speakers soundstage. But, no headphones will be like speakers any time soon. Also, these headphones are around 1,000 bucks now, and to me sound far better dynamically and in terms of holography than almost all of the planar masterpieces which do have their strengths but just aren’t for me.
I'm assuming you're referring to its coefficient of thermal expansion. If the voice coil wire is expanding at a different rate with temperature than the former, this is not necessarily a positive attribute. You often have to look at multiple interactions to determine the benefit of a particular material.
And if you want low expansion, this site says titanium is better.
https://www.engineeringtoolbox.com/thermal-expansion-metals-d_859.html
Companies like Purifi are out there trying to make significant improvements in performance. They and others have obviously studied the components and the whole, and decided where to put dollars to get the greatest improvements. My general take on things like this is there's often a good reason items like this don't exist. The market these days will bear a lot of cost, if it gives significant benefit.
https://purifi-audio.com/ptt6-5x04-nfa-01/
Last edited:
https://audioxpress.com/article/Voice-Coil-Spotlight-The-Beryllium-Advantage
"Early beryllium components were manufactured through a method known as physical vapor deposition (PVD), which is a process that involves depositing thin layers through the condensation of the vaporized element onto a form. Unfortunately, this method not only limits thickness, but also produces a relatively coarse grain structure that is more likely to generate potentially harmful breathable particles if breakage occurs.
In recent years; however, Materion Electrofusion has pioneered the use of rolled-foil beryllium for acoustic applications. Its Truextent beryllium foil benefits from the rolling process by achieving a more durable grain structure and the minimization of residual internal strains. As a result, rolled-foil beryllium components are significantly tougher, and when failure does occur, they generally do not result in breathable particles."
"Early beryllium components were manufactured through a method known as physical vapor deposition (PVD), which is a process that involves depositing thin layers through the condensation of the vaporized element onto a form. Unfortunately, this method not only limits thickness, but also produces a relatively coarse grain structure that is more likely to generate potentially harmful breathable particles if breakage occurs.
In recent years; however, Materion Electrofusion has pioneered the use of rolled-foil beryllium for acoustic applications. Its Truextent beryllium foil benefits from the rolling process by achieving a more durable grain structure and the minimization of residual internal strains. As a result, rolled-foil beryllium components are significantly tougher, and when failure does occur, they generally do not result in breathable particles."
https://audioxpress.com/article/Voice-Coil-Spotlight-New-in-Voice-Coils
"Titanium is appealing when compared to aluminum because there are less eddy currents . . ."
http://www.nessengr.com/techdata/metalresis.html
This is an auto-translated patent, so grammar is off here and there
https://patents.google.com/patent/DE3904373A1/en
"The disadvantages of bobbins made of highly conductive metals primarily from the eddy current formation in the coil body itself.
. . .
permanent braking effects so great that they have a significant damping represent the coil movement in the air gap of a magnet.
This is often a desired effect, but due to the also existing magnetic feedback on the movement causing signal current to higher frequencies a considerable Frequency dependence of the impedance. It means that in addition to the braking effect, a deterioration of the Rise time is caused by the increased coil impedance.
Eddy current formation can also be avoided by looking for the voice coil bobbin metals with higher specific resistances used, such as titanium or constantan."
"Titanium is appealing when compared to aluminum because there are less eddy currents . . ."
http://www.nessengr.com/techdata/metalresis.html
| Metal | Resistivity (µΩ-cm.) | Resistivity (Ohm / mil ft.) | Temperature Coefficient of Resistance / deg. C |
| Aluminum | 2.7 | 16.2 | 0.004 |
| Beryllium | 4.5 | 27.0 | 0.025 |
| Titanium | 43.0 | 259.0 | 0.0035 |
This is an auto-translated patent, so grammar is off here and there
https://patents.google.com/patent/DE3904373A1/en
"The disadvantages of bobbins made of highly conductive metals primarily from the eddy current formation in the coil body itself.
. . .
permanent braking effects so great that they have a significant damping represent the coil movement in the air gap of a magnet.
This is often a desired effect, but due to the also existing magnetic feedback on the movement causing signal current to higher frequencies a considerable Frequency dependence of the impedance. It means that in addition to the braking effect, a deterioration of the Rise time is caused by the increased coil impedance.
Eddy current formation can also be avoided by looking for the voice coil bobbin metals with higher specific resistances used, such as titanium or constantan."
Last edited: