It's exceptionally rare in woofers for a reason, it's pretty much not feasible to do it in larger sizes. In fact I am at the moment unaware of any Be cone woofers. AlMg is common though.
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What is generally the best material for speaker cones with the least compromise and most benefits?
- Thread starter CleanSound
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I don't agree with this. I think the value companies would all use it (unless it was a precious metal, or dangerous, or something), but the audiophile brands would insist on using rare, weird, or really expensive materials (wood, plasma, tungsten), charging a huge markup, and insisting on their unmeasured benefits.
OP
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At most only mid-range.
There are only two models that I am aware of.
The legendary NS-1000/2000 https://en.wikipedia.org/wiki/NS-2000
and the Paradigm Persona
Anything larger than that is not only hard to do, but the physical properties becomes challenging for low frequencies. (at least that's what I read on the wild wild internet)
The only application where Be makes sense is in a midrange, and even then, the advantages would only be relevant in a very specific use case. The breakup of tweeters is already ultrasonic for every other material, so no real advantage there. Woofers simply don't need materials that rigid given how slowly they move, and for the bandwidth they are designed for - a more ductile cone is probably advantageous if you're hitting it with a 4" voice coil and 500 watts. And regarding the NS-1000, it was an amazing piece of engineering...for 1974. Back then they measured frequency response with a device resembling a seismograph.
A small, very rigid Be midrange might make sense, but why would you want to run a midrange up high to begin with? The only other application it makes sense is in larger compression diaphragms, but even then it is as much for durability as sound quality.
There's an insidious 'luxury mindset' in audio, which assumes that the more expensive and difficult a thing is, the better it is. This simply isn't the case.
If you want to look at the ultimate in esoteric midrange engineering, look at the scanspeak Ellipticor D8404/552000. This thing has a beautifully machined waveguide, an elliptical motor structure, neodymium magnet array and the diaphragm is coated textile. It costs $2.5k each.
When sb acoustics, scanspeak and purifi want to make the most sophisticated small woofers in the world, what materials do they use? Paper - sometimes with a coating, or some odd fibers mixed in - but you pay for the time it takes to make the cone geometry perfect, the glue dialed in, the surround geometry idealized, the indentations and cuts perfect.
In speaker engineering, you don't pay for materials, you pay for the insane R&D involved in managing dozens of resonances you know the source of and hundreds you don't know the source of.
A small, very rigid Be midrange might make sense, but why would you want to run a midrange up high to begin with? The only other application it makes sense is in larger compression diaphragms, but even then it is as much for durability as sound quality.
There's an insidious 'luxury mindset' in audio, which assumes that the more expensive and difficult a thing is, the better it is. This simply isn't the case.
If you want to look at the ultimate in esoteric midrange engineering, look at the scanspeak Ellipticor D8404/552000. This thing has a beautifully machined waveguide, an elliptical motor structure, neodymium magnet array and the diaphragm is coated textile. It costs $2.5k each.
When sb acoustics, scanspeak and purifi want to make the most sophisticated small woofers in the world, what materials do they use? Paper - sometimes with a coating, or some odd fibers mixed in - but you pay for the time it takes to make the cone geometry perfect, the glue dialed in, the surround geometry idealized, the indentations and cuts perfect.
In speaker engineering, you don't pay for materials, you pay for the insane R&D involved in managing dozens of resonances you know the source of and hundreds you don't know the source of.
MAB
Major Contributor
The exotic tweeter materials craze is odd. I hope nobody figures out how to reasonably manufacture Beryllium cones of any diameter.
Let's look at some exotic materials in tweeters...
For instance some Scan Speak tweeters:
Perhaps diamond?
Some Seas tweeters.
I look at the obsession with exotic materials as a challenge to make a good speaker despite the exotic materials, not because of them...
Some of the worst commercial speakers I have heard have Be tweeters, although I tend to think they are voiced obnoxiously bright because the customer is going to expect the tweeter to shout out.
I still think paper woofers look fantastic, and sound great too:
So many engineering problems can and be solved in the driver with paper.
Exotic materials mostly require additional effort and approaches to deal with the problems they bring, like ultra-light and stiff magnesium:
www.audiosciencereview.com
I don't believe there is a best materials for speaker cones. If there is one, it's probably paper.
Let's look at some exotic materials in tweeters...
For instance some Scan Speak tweeters:
Perhaps diamond?
Some Seas tweeters.
I look at the obsession with exotic materials as a challenge to make a good speaker despite the exotic materials, not because of them...
Some of the worst commercial speakers I have heard have Be tweeters, although I tend to think they are voiced obnoxiously bright because the customer is going to expect the tweeter to shout out.
I still think paper woofers look fantastic, and sound great too:
So many engineering problems can and be solved in the driver with paper.
Exotic materials mostly require additional effort and approaches to deal with the problems they bring, like ultra-light and stiff magnesium:
Active DSP DIY speakers, for testing a few ideas
FFLOTSAM (Fabricated From LeftOver Things Studio Active Monitor) Active DSP speakers, for testing a few ideas I had some stuff lying around; a few random Baltic Birch-ply panels, some countertop material, a few cans of partially used brown spray paint, and some not-too clumpy spar varnish (that...
www.audiosciencereview.com
I don't believe there is a best materials for speaker cones. If there is one, it's probably paper.
That Scan Speak Classic isn’t the prettiest driver. I am surrounded with 5 of them at Center, Surround and Rear.The exotic tweeter materials craze is odd. I hope nobody figures out how to reasonably manufacture Beryllium cones of any diameter.
Let's look at some exotic materials in tweeters...
For instance some Scan Speak tweeters:
View attachment 325014
Perhaps diamond?
Some Seas tweeters.
View attachment 325015
I look at the obsession with exotic materials as a challenge to make a good speaker despite the exotic materials, not because of them...
Some of the worst commercial speakers I have heard have Be tweeters, although I tend to think they are voiced obnoxiously bright because the customer is going to expect the tweeter to shout out.
I still think paper woofers look fantastic, and sound great too:
View attachment 325016
So many engineering problems can and be solved in the driver with paper.
Exotic materials mostly require additional effort and approaches to deal with the problems they bring, like ultra-light and stiff magnesium:
Active DSP DIY speakers, for testing a few ideas
FFLOTSAM (Fabricated From LeftOver Things Studio Active Monitor) Active DSP speakers, for testing a few ideas I had some stuff lying around; a few random Baltic Birch-ply panels, some countertop material, a few cans of partially used brown spray paint, and some not-too clumpy spar varnish (that...
I don't believe there is a best materials for speaker cones. If there is one, it's probably paper.
They are solid performers.
mhardy6647
Grand Contributor
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'zackly. Saw lots of "cones" being mentioned. Indeed, I had typed a cone-centric (so to speak) reply but deleted it when I saw your edit.
Thus I urged my hifi fellow travelers to note well that the OP dude had added "I'm only talking in the world of compression speakers."
MAB
Major Contributor
I was thinking about this. Agree, Beryllium does push that mode to way outside of audibility, but the breakup is really dramatic! Same with Seas Excel woofers (for example), great low-distortion response until the breakup mode and you get a 12dB peak. I think the drivers are great but more difficult to work with.
Regarding the mass. I am not sure how much mass matters, but that isn't an area where Beryllium is outstanding. Here are a bunch of drivers of different materials. I graph them all vs. piston area.
Roughly normalized for area, Beryllium is in the middle of the distribution. The ScanSpeak Discovery D2608/9130 is the lowest mass/area. I'm not saying Beryllium is bad, it just confuses me!
Here are the masses and areas from various manufacturers:
| Material | Model | Moving Mass (g) | Effective Piston Area |
| Beryllium | ScanSpeak D3004/6040-10 | 0.35 | 7 |
| Textile | SEAS Excel T25CF-001 (E0006) | 0.33 | 7 |
| Textile | SEAS Excel T25CF-002 (E0011) | 0.37 | 7 |
| Textile | SEAS Excel T29CF-002 (E0040) | 0.35 | 8 |
| Textile | Seas Excel T35C-002 | 0.47 | 11.9 |
| Textile | Seas Exotic T35 X3-06 | 0.47 | 11.9 |
| Textile | Seas Prestige 19TFF1 (H0737) | 0.23 | 4 |
| Textile | SEAS Prestige 25TFFC (H0519) | 0.3 | 7 |
| Textile | SEAS Prestige 27TDC (H1149) | 0.3 | 7 |
| Textile | SEAS Prestige 27TDFC (H1189) | 0.37 | 7.5 |
| Textile | SEAS Prestige 27TFFC (H0881) | 0.25 | 7.6 |
| Textile | SEAS Prestige 27TFFNC/G (H1396) | 0.26 | 7.5 |
| Textile | SEAS Prestige 29TFF/W (H1318) | 0.35 | 8 |
| Textile | ScanSpeak Discovery H2606/9200 Horn | 0.4 | 5.7 |
| Textile | ScanSpeak Classic D2010/8513 | 0.25 | 3.8 |
| Textile | ScanSpeak Classic D2010/852100 | 0.2 | 3.8 |
| Textile | ScanSpeak Classic D2008/8512 | 0.25 | 3.8 |
| Textile | ScanSpeak Classic D2008/852100 | 0.2 | 3.8 |
| Textile | ScanSpeak Classic D2905/9500 | 0.45 | 8.5 |
| Textile | ScanSpeak Classic D2905/9700 | 0.45 | 8.5 |
| Textile | ScanSpeak Discovery D2604/8300 | 0.42 | 8 |
| Textile | ScanSpeak Discovery D2606/9200 | 0.3 | 7.1 |
| Textile | ScanSpeak Discovery D2606/9220 | 0.33 | 7.1 |
| Textile | ScanSpeak Discovery D2608/9130 | 0.18 | 7 |
| Textile | ScanSpeak Ellipticor D2404/5520-00 | 0.34 | 4.6 |
| Textile | ScanSpeak Ellipticor D3404/5520-00 | 0.57 | 11.4 |
| Textile | ScanSpeak Illuminator D3004/6020-00 | 0.35 | 7 |
| Textile | ScanSpeak Illuminator D3004/6600 | 0.35 | 7 |
| Textile | ScanSpeak Revelator D2104/7120-00 | 0.22 | 4.5 |
| Textile | Scan-Speak Ellipticor D8404/552000 | 5.75 | 57.8 |
| Metal | SEAS Prestige 22TAF/G (H1283) | 0.23 | 5.9 |
| Metal | SEAS Prestige 27TBFC/G (H1212) | 0.34 | 7.5 |
| Metal | SEAS Prestige 27TBCD/GB-DXT | 0.33 | 7.5 |
| Metal | SEAS Prestige Titan 27TAC/GB | 0.36 | 7.3 |
| Ceramic | Accuton Cell C30-6-358 | 0.28 | 8.55 |
| Ceramic | Accuton Cell C25-6-158 | 0.17 | 5.94 |
| Ceramic | Accuton C25-6-012 | 0.23 | 5.94 |
| Ceramic | Accuton C30-6-024 | 0.49 | 8.55 |
| Textile | Satori MD60N-6 | 2 | 32 |
| Textile | Morel MDM55 | 2.8 | 28 |
| Textile | Morel EM1308 Elite | 3 | 28 |
| Textile | ScanSpeak Discovery D7608/9200-10 | 3.3 | 55 |
| Beryllium | ScanSpeak D2908/7140 | 0.33 | 7 |
| Beryllium | ScanSpeak Illuminator D3004/6040-00 | 0.24 | 7 |
| Beryllium | ScanSpeak Illuminator D3004/6040-10 | 0.35 | 7 |
| Beryllium | Scanspeak Illuminator D3004/6640-00 | 0.35 | 7 |
| Beryllium | Seas Excel T29B001 | 0.3 | 8 |
| Beryllium | Satori TW29B-B | 0.46 | 9.6 |
| Beryllium | Satori TW29BN-B-8 | 0.44 | 9.6 |
MAB
Major Contributor
My attitude towards Beryllium doesn't keep me from wanting these:
usa.yamaha.com
:
History of Speaker - Yamaha - United States
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In the end though the specific stiffness matters (that is per mass unit) and there Beryllium has one of the highest values (and the highest of all metals):
Specific modulus - Wikipedia
MAB
Major Contributor
Agree on the technical merits. But looking at the response of the various drivers, all of the Be tweeters have worse off axis response than a typical textile dome. For instance two of ScanSpeak's drivers:In the end though the specific stiffness matters (that is per mass unit) and there Beryllium has one of the highest values (and the highest of all metals):
Of course ideally you might want also a high specific damping, although if that first break up mode quite above 20 kHz has audible consequences is questioned.Specific modulus - Wikipedia
en.wikipedia.org
The dotted line is my trace of the D2908's 30 and 60 degree off-axis responses. To my eye, the D2904 is a more useable tweeter, slightly better sensitivity, considerably better off axis performance. Both are lightly waveguided, I'm not qualified to judge the exact differences there. Does the Be-proof screen mess up the off-axis response? That would be ironic!
Come to think of it, isn't it strange that we have so many material science research into cables like cyro and single crystal, and also resonator cups and spikes and suspension and absorbers and CD weights, and even earth radiation resonators
Yet we never see these research make their way into speakers
I was thinking of gold speakers
Yet we never see these research make their way into speakers
I was thinking of gold speakers
Last edited:
robh
Member
A better answer might be spreadsheet/chart of the pros and cons of each type, or a rating from 1-5 on various aspects such as ease-of-use, driver longevity, sound quality, etc. ie. Paper might score high on ease-of-use, but low on longevity, especially with foam surrounds Lol.
I'm sure all the functional differences and their challenges exist in the minds of speaker designers, but not sure if that's ever been put to paper.
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A soft dome starts usually breaking partially up already in the audio band, effectively reducing the active radiating surface and thus also the geometry related beaming.Agree on the technical merits. But looking at the response of the various drivers, all of the Be tweeters have worse off axis response than a typical textile dome. For instance two of ScanSpeak's drivers:
View attachment 325128
The dotted line is my trace of the D2908's 30 and 60 degree off-axis responses. To my eye, the D2904 is a more useable tweeter, slightly better sensitivity, considerably better off axis performance. Both are lightly waveguided, I'm not qualified to judge the exact differences there. Does the Be-proof screen mess up the off-axis response? That would be ironic!
MAB
Major Contributor
Thanks. That makes sense..
Frankly, for a typical two-way speaker a material like paper is often better than exotics, since the polar pattern can be less pistonic. Some paper drivers have surprisingly good dispersion well above where an ideal piston would not, allowing them to blend nicely with a dome tweeter. So once again: it all depends.
Ride that proprietary material difference.
harbeth.co.uk
There's also a video of him showing paper deforming under pressure vs RADIAL. No word on whether carbon fiber, stiffer paper, diamond, etc. de-form under pressure.
Harbeth's history in speaker cone research - Harbeth
The hear of today’s Harbeth sound is our unique, Patented, RADIAL™ cone material.
harbeth.co.uk
There's also a video of him showing paper deforming under pressure vs RADIAL. No word on whether carbon fiber, stiffer paper, diamond, etc. de-form under pressure.
Take a look at the W18 graphs above, near 5kHz. Obviously, those rather stiff cones deform rather badly up there.Ride that proprietary material difference.
Harbeth's history in speaker cone research - Harbeth
The hear of today’s Harbeth sound is our unique, Patented, RADIAL™ cone material.
There's also a video of him showing paper deforming under pressure vs RADIAL. No word on whether carbon fiber, stiffer paper, diamond, etc. de-form under pressure.
