How much impact does driver material actually make?

[2020]

I didn't know where to post this, but this moribund thread seems to address the issue.

A dealer who posts on the AVSForums 'Revel Owners Thread' posted this about the supply of beryllium for tweeter production. He posted this in response to a post that hoped the upcoming Revel Performa 4 line of speakers might include beryllium tweeters. I take no responsibility beyond the repost of the info....

"Here is something to think about.

It has recently become much harder to get beryllium for loudspeaker tweeters. The main supplier of the beryllium sheet metal used for high-end acoustic domes, Materion, discontinued the product in the necessary thickness, causing major supply chain disruptions.

• A sudden halt: Speaker manufacturers like Scan-Speak and brands that use their drivers, including BlieSMa, were reportedly informed without prior notice.
• No easy alternatives: The unique, delicate nature of beryllium domes means there are no readily available alternative manufacturers to fill the gap.
• Industry-wide impact: This affects multiple high-end audio companies that relied on the specialized beryllium material for their premium tweeters.

What this means for beryllium tweeters.

• Reduced availability: Beryllium tweeters may become scarcer in the market
• Changes in design: As a result, loudspeaker engineers are likely to explore and design around alternative materials with more consistent availability.
• Potential price increases: The limited supply of the raw material could also drive up the cost of any remaining beryllium tweeters on the market.

We don’t know what the long-term plan is, but they are not going away. However, the material is going to be hard to get, and therefore so will the tweeters and the speakers that use Be tweeters. We need to plan for them becoming difficult or impossible to get in the near future.

If you are thinking about purchasing Revel speakers with Beryllium tweeters, you should do it very soon. Feel free to contact me, I can find out what is currently available."

This dealer is very helpful and informative on AVSForum, and is considered a 'straight-shooter.'

Goodbye beryllium, hello diamond? Synthetic (lab grown) diamonds make it cheap too.

 

[steve59]

Vivid brand speakers use aluminum for their drivers and there's a fair amount of reviews that suggest their drivers are every bit as advanced as KEF. As 'The fifth element' is one of my favorite sci fi's so I can't get over the Vivid cabinet look, but despite their odd appearance they're serious products.

 

[dped90]

There is some sort of truth to this statement, though, as several Beryllium tweeters

Beryllium tweeters, such as those from Revel or TAD. But how likely would the same problems arise with 3" or 4" Be drivers from JBL or 18Sound used in a two-way speaker system?

Btw, any experience with Radian Be drivers, such as
https://www.usspeaker.comradian%20745neoBepb-1.htm

I thought of using them with a 1.4" 18Sound or Faital horn above my midwoofers.

Altec 416-8B in 100L Sealed

In this blog post I test the Altec 416-8B in a 100L sealed enclosure. Testing was done outdoors for the frequency response and then brought indoors for the distortion testing. The woofers are new from Great Planes Audio. A customer has sent me the finished cabinets with drivers to integrate...

josephcrowe.com

But I've heard that their "outdated" phase plugs are often not compatible with horns, and/or that it's more difficult to EQ them for flatter HF response than JBL and 18Sound drivers.

 

[dped90]

We need to plan for them becoming difficult or impossible to get in the near future.

How much can this ongoing problem be due to this apparent sweetheart deal between a lone compression driver manufacturer, the world's single biggest beryllium supplier, and their best customer the weapons makers?

https://investor.materion.com/news/...nt-Acoustic-Beryllium-Diaphragms/default.aspx

Go here https://www.usspeaker.com/ , click Radian and scroll down to Be diaphragms.

So, let's be honest with ourselves: Things are not going to change until consumers-that is speaker brands and the DIY community-speak up and loud about this unfair situation. https://www.materion.com/en/markets/consumer-electronics

https://hkvxni.files.cmp.optimizely...ng+Guide.pdf/f35b2af092fc11f0b3c68668ee5e8a84

 

[Arindal]

But how likely would the same problems arise with 3" or 4" Be drivers from JBL or 18Sound used in a two-way speaker system?

Not aware of any direct-radiating 3" or 4" Be diaphragms running high enough in frequency. In a compression chamber, or combined with a bigger horn, the phenomenon I have described, is basically non-existent, as the diaphragm geometry is not identical to the shape and size of the actual wavefront generated. With most compression drivers, the wavefront (if you want to speak of a wavefront at all), is much smaller and much less likely to be flat, as this poses problems inside a horn which you want to avoid at any cost.

Vivid brand speakers use aluminum for their drivers ... but despite their odd appearance they're serious products.

Not saying they are bad, but they are actually examples of speakers showing a pretty broad dispersion pattern in some rather narrow frequency bands. It is inherent to their baffle-less design, similarities to the 1st gen B&W Nautilus are not coincidental.

 

[Heinrich]

... not compatible with horns, and/or that it's more difficult to EQ them for flatter HF response than JBL and 18Sound drivers.

Speaking of Be equipped compression drivers you say it yourself. The problem is the phase plug and the connection to the horn, a high resonance frequency / break up of the dome isn't a solution alone. This shows again, that "better go Be" is a superficial perpective of laypeople made to believe in expensive boutique parts w/o any use.

Anecdotally, the switch from aluminum to titanium in JBL drivers was due to the brittleness of aluminum, that was used for the surround also. It cracked after a while in operation. Titanium wasn't chosen because of its strength (under very high temp/ like a few hundret degrees celcius). It was its persisting flex/. Radian went te other way and still offer excellent dias for the older JBL drivers made of al/alloy with a plastic surround, 20k no prob/ with these. When did you last got your ears checked ;-)

Don't believe the hype, it is fraud in my book.

 

[Arindal]

that "better go Be" is a superficial perpective of laypeople made to believe in expensive boutique parts w/o any use.

I agree that it is not the exotic material alone guaranteeing better sound quality. On the other hand, Be offers a pretty unique combination of parameters in case you need a combination of stiff, light-weight and almost flat diaphragm plus break-up frequency well above the typical range.

Anecdotally, the switch from aluminum to titanium in JBL drivers was due to the brittleness of aluminum, that was used for the surround also.

If diaphragm geometry and crossover were not meticulously optimized for the given material, that is pretty anecdotally. There are very good aluminum domes on the market was well, but they somehow deal with the properties of this particular metal.

 

[mhardy6647]

yeah, but beryllium is both exotic and toxic! The perfect audiophile combination:

Experience beryllium before you die! Perhaps only slightly before. It's life changing!

Plutonium's probably prohibitively expensive, even for a supertweeter diaphragm.

 

[dfuller]

The way I see it, you can get similar performance out of Al-Mg alloys as Be, it's just harder to get there. Getting close to Be's breakup behavior (ie, far ultrasonics) requires some pretty intense engineering.

Bliesma has managed to push the breakup of a 25mm Al dome out to about 34-35k using a variable thickness diaphragm. Doing that with Be doesn't require any tricks.

However both are not audible concerns as there is so little energy up there in most program material that the chances of exciting it is basically nill. It's not like a cheap Ti dome with a severe oil can resonance barely above the audible range which very well could be set off by average program material.

 

[Arindal]

but beryllium is both exotic and toxic!

Beryllium in cold, elemental form is not toxic AFAIK, although some people might show allergic reaction when touching it with wet, slightly acidic skin. As salt, oxide, fume or dust it is dangerous, though, but that is not really what comes out of a loudspeaker.

Bliesma has managed to push the breakup of a 25mm Al dome out to about 34-35k using a variable thickness diaphragm.

To be fair, Bowers&Wilkins did this years ago already with a two-layered dome.

However both are not audible concerns as there is so little energy up there in most program material that the chances of exciting it is basically nill.

Noticeable ringing at the resonance frequency of 35k is rather unlikely, I agree. Nevertheless a dome might show strange directivity behavior an octave below this particular frequency, depending on its geometry.

 

[bigguyca]

I didn't know where to post this, but this moribund thread seems to address the issue.

A dealer who posts on the AVSForums 'Revel Owners Thread' posted this about the supply of beryllium for tweeter production. He posted this in response to a post that hoped the upcoming Revel Performa 4 line of speakers might include beryllium tweeters. I take no responsibility beyond the repost of the info....

"Here is something to think about.

It has recently become much harder to get beryllium for loudspeaker tweeters. The main supplier of the beryllium sheet metal used for high-end acoustic domes, Materion, discontinued the product in the necessary thickness, causing major supply chain disruptions.

• A sudden halt: Speaker manufacturers like Scan-Speak and brands that use their drivers, including BlieSMa, were reportedly informed without prior notice.
• No easy alternatives: The unique, delicate nature of beryllium domes means there are no readily available alternative manufacturers to fill the gap.
• Industry-wide impact: This affects multiple high-end audio companies that relied on the specialized beryllium material for their premium tweeters.

What this means for beryllium tweeters.

• Reduced availability: Beryllium tweeters may become scarcer in the market
• Changes in design: As a result, loudspeaker engineers are likely to explore and design around alternative materials with more consistent availability.
• Potential price increases: The limited supply of the raw material could also drive up the cost of any remaining beryllium tweeters on the market.

We don’t know what the long-term plan is, but they are not going away. However, the material is going to be hard to get, and therefore so will the tweeters and the speakers that use Be tweeters. We need to plan for them becoming difficult or impossible to get in the near future.

If you are thinking about purchasing Revel speakers with Beryllium tweeters, you should do it very soon. Feel free to contact me, I can find out what is currently available."

This dealer is very helpful and informative on AVSForum, and is considered a 'straight-shooter.'

- You should have emphasized the key portion of the marketing guy's post as underlined and bolded above. There were issues with Beryllium foil, but not a catastrophe. Revel has other issues IMO.

Revel's product line has undergone many changes with many models dropped over the past year and of course, the company has effectively had several different owners. Most of these dropped models were not the Be models. Selected Be models have been available at very discounted prices, sometimes more than 50% off, over the past year. U.S. Audio Mart seems to still have some listings by folks who bought the models to flip.

Once Sydney Harman was no longer involved with Harman International and thus Revel, a decline began IMO. I believe the F208, a great speaker for the price, was the last model designed when Sydney Harman was involved. The F36, 2 1/2-way replacing the 3-way F12, instead of upgrading the F12, is an example of a clear step in the wrong direction. Dropping the non-Be Performa line was very unfortunate for customers.

- Beryllium: The U.S. is the largest producer of beryllium in the world. Materion is the major (only?) producer in the U.S. Materion is still selling acoustic beryllium.

MATERION'S TRUEXTENT ACOUSTIC BERYLLIUM SPEAKER DOMES, CONES & ASSEMBLIES

LEARN MORE ABOUT HOW ACOUSTIC BERYLLIUM FOR AUDIO DOMES AND CONES ENABLE CRYSTAL-CLEAR SOUND REPRODUCTION

www.materion.com

- Here is Grok's view of the Beryllium foil market.

Beryllium foil, valued for its exceptional stiffness-to-weight ratio, is primarily used in high-end loudspeaker tweeters (and sometimes midrange drivers) to produce clear, distortion-free high frequencies. The supply situation for this specialized material has experienced some challenges in recent years, but as of 2025, it appears stable overall, albeit with a small market size, higher costs, and shifts among manufacturers. Below is a breakdown based on current market dynamics.

Key Suppliers and Production​

• Materion Corporation (based in the US) is the dominant global supplier of beryllium products, including acoustic-grade beryllium foil (branded as Truextent). They mine, process, and fabricate beryllium into foils, domes, cones, and full diaphragm assemblies for loudspeakers and headphones. Materion has expanded production capacity at its Utah facility to meet growing demand across industries (not just audio), amid tightening global supplies. They continue to offer custom acoustic beryllium products in various sizes for tweeters, midranges, woofers, and compression drivers, with no public announcements of broad discontinuations in 2025.
• Other sources include limited production in China and Kazakhstan, but these are not major players in high-purity acoustic foil. Global beryllium extraction is low-volume due to the element's rarity and toxicity, which requires specialized handling.

Market Size and Trends​

• The beryllium foil market is niche, especially for audio applications. For example, the European market was valued at about USD 0.03 billion in 2022 and is projected to grow to USD 0.05 billion by 2033. Globally, demand for acoustic use remains small compared to aerospace, defense, and electronics, which can strain specialized supply chains.
• Recent forecasts indicate steady growth through 2030, but with potential impacts from U.S. tariffs and trade dynamics in 2025, which could raise costs or disrupt imports. Materion reported macroeconomic pressures and supply chain disruptions in its Q1 2025 earnings, though these are not specific to audio foil.

Recent Supply Challenges and Resolutions​

• In 2023, Materion abruptly discontinued a specific type of beryllium foil sheet without notice, impacting third-party loudspeaker driver manufacturers like Scan-Speak and SEAS. This led to temporary shortages and "material issues" halting production of several beryllium dome tweeter models (e.g., Scan-Speak's D2908/714000 and D3004 series). Reasons cited include the small market making it uneconomical, rising costs (foil prices reportedly jumped from $20–40 to over $120 per dome), toxicity concerns (beryllium dust is hazardous, leading to stricter regulations), and general beryllium shortages with lead times exceeding 40 weeks.
• By 2025, affected companies have adapted:
  • Scan-Speak replaced its beryllium tweeters with new TPCD (TeXtreme PolyCarbonate Diaphragm) metamodal models, which are now available as alternatives.
  • Other brands like Bliesma, SB Acoustics/Satori, and some DIY suppliers faced similar issues but have either switched materials or sourced alternatives.
  • Vertically integrated companies like Focal (which produces its own beryllium tweeters) and Magico remain unaffected and continue offering beryllium-based products without reported shortages.
• No widespread shortages are reported in 2025 industry coverage, such as at events like AXPONA or High End Munich, where beryllium-equipped loudspeakers (e.g., from Paradigm, Audiovector, and others) are still prominently featured.

Availability for Buyers​

• For loudspeaker manufacturers or DIY enthusiasts, acoustic beryllium foil is available directly from Materion in custom forms, though minimum orders and lead times may apply due to the material's handling requirements.
• End-users can find beryllium in premium speakers from brands like Focal, Magico, Paradigm, and Bang & Olufsen, with no evident retail shortages.
• If supply tightens further, alternatives like diamond-coated, Textreme, or soft-dome tweeters are increasingly common and perform comparably in many applications.

Overall, while past disruptions caused ripple effects, the supply situation in 2025 is manageable, with ongoing production from key players like Materion supporting the audio industry's needs. If you're seeking specific quotes or purchases, contacting Materion directly would provide the most up-to-date details.

Credit: Grok

 

[dfuller]

To be fair, Bowers&Wilkins did this years ago already with a two-layered dome.

I mean, obviously it's possible. I think Neumann did something similar where they just added a fabric layer to squelch the breakup.

Noticeable ringing at the resonance frequency of 35k is rather unlikely, I agree. Nevertheless a dome might show strange directivity behavior an octave below this particular frequency, depending on its geometry.

Luckily, it doesn't. In fact, its behavior is remarkably good for a dome tweeter, in that it isn't even really beaming at 20k.

- Here is Grok's view of the Beryllium foil market.

I know it's not a rule of the forum, but personally I find copy/pasting LLMs to be at best low effort and at worst just straight up wrong.

 

[Heinrich]

Luckily, it doesn't. In fact, its behavior is remarkably good for a dome tweeter, in that it isn't even really beaming at 20k.

You know it from elsewhere, spreading suspicion on and of everything on the world, which is counterfeit of scientific scrutiny.

In this case it was, there's resonance, too high in frequency to be heard, but there is influence an octave below, according to forum rules it has to be: "directivity", so it is to be heard somehow maybe by some.

No, there is nothing! The notion isn't reasonable, no proof given, not even as a concept of proof, no rational chain of causation on what and by which and so forth ...

... copy/pasting LLMs to be at best low effort ...

These little creepers, the LLMs I mean, copy the internet, as it seems, just talking ...