Midrange dome drivers banned ?

[Frank Dernie]

Zylon is a synthetic polymer fiber. Claiming it's "technically the best" speaker material is nothing but marketing speak in the absence of scientific proof within the audio community.

This is true.
Zylon almost certainly doesn't produce a dome without breakup in the audible range but can be made with a matrix (the polymer used to bond the fibres together) with far more damping than any metal so maybe keeping the in band peaks in check, like with any other soft dome.

 

[Frank Dernie]

Another reason for Yamaha's selection of Zylon is that Beryllium metal is possibly toxic, or would pollute environment, when it would be broken into powders... Yamaha is such a big company and they should be careful enough about possible social responsibility for any kind of even rare cases of damages to people, consumers and environment, I believe. They need to show such a preventive attitude to the society.

TAD is still using vacuum vapor deposition Beryllium metal in their drivers, though...

I think the reason they stopped using Beryllium is more due to cost than environmental concerns.

 

[Frank Dernie]

[QUOTE="jtgofish, post: 865840, member: 34919"

No.There are very good technical reasons why Zylon is a superior material.[/QUOTE]

Please list any of them.
It doesn't have any special properties ideal for driver diaphragms that I am aware of.
I have only used it for the wheel tethers on Formula 1 cars where its elasticity and long extension to failure and energy absorbtion for a given weight make it a top choice.
None of these excellent characteristics are exploited when it is used in a speaker driver.

 

[jtgofish]

and then there's ZYLON® — an ultra-strong synthetic fiber with exceptionally high acoustic velocity, double that of titanium or magnesium and comparable to that of beryllium.12 Nov 2019

 

[Frank Dernie]

and then there's ZYLON® — an ultra-strong synthetic fiber with exceptionally high acoustic velocity, double that of titanium or magnesium and comparable to that of beryllium.12 Nov 2019

Comparable acoustic velocity but inferior stiffness.

 

[jtgofish]

Comparable acoustic velocity but inferior stiffness.

There is hardly any difference in stiffness.Youngs Modulus 270 for Zylon and 287 for beryllium.They are both extremely stiff.
Kevlar is only around 90.

 

[Frank Dernie]

There is hardly any difference in stiffness.Youngs Modulus 270 for Zylon and 287 for beryllium.They are both extremely stiff.
Kevlar is only around 90.

Yes but you are making a common error when comparing a reinforcing fibre to a homogeneous material. By the time the fibre is laid up in a woven or even UD matrix the mechanical properties are considerably lower than those of the fibre alone and will vary with load orientation due to fibre orientation in the composite, whereas the homogeneous material maintains its properties in all directions.

 

[More Dynamics Please]

So there's some evidence that Zylon could be a good speaker material but no definitive audio industry conclusion that it's "technically the best" despite any such claims by Yamaha's marketing department. By the way, Zylon was previously discussed in this year-old ASR thread:

https://www.audiosciencereview.com/...act-does-driver-material-actually-make.17255/

 

[jtgofish]

Yes but you are making a common error when comparing a reinforcing fibre to a homogeneous material. By the time the fibre is laid up in a woven or even UD matrix the mechanical properties are considerably lower than those of the fibre alone and will vary with load orientation due to fibre orientation in the composite, whereas the homogeneous material maintains its properties in all directions.

Perhaps that is why Yamaha uses Zylon treated with Monel.
Zylon has a 20% better weight to stiffness ratio than beryllium.
But really the main advantage of using Zylon is that all three drivers can be made from the same material .Which should bring gains in terms of driver integration.Some companies like Focal have done that with Kevlar but Zylon would appear to be a superior material to Kevlar or carbon.ISo perhaps it would be fair to claim that Zylon is the best possible material to use if you are wanting to use the same material for all drivers. Have you ever seen a 12 inch pure beryllium woofer?

 

[Doodski]

Have you ever seen a 12 inch pure beryllium woofer?

I don't think a hunk of beryllium could be put in a press and squished out to that size without deformation and other issues. That's how Focal makes their tweeter. In a press between dies.

 

[gene_stl]

Plasma tweeters are one of the stupidest ideas ever to hit the light of day.
The ones using Helium waste a strategic resource that is now required to be recovered by scientific labs. It has gotten quite expensive. Of course you also could use argon which is distilled from air.
(And yes I have heard them and if anyone wants to buy my pair of Ionovac tweeters please private message me)

Martin Collums the designer of many of the aforementioned Monitor Audio speakers wrote a book in the mid to late seventies called high performance loudspeakers. In it he said that the Yamaha beryllium drivers had the lowest distortion he had ever measured. (Separate mentions in chapters on midranges and tweeters) I have not seen anything since then that tempted me very much. I love restorer-johns remarks on the subject. It's always nice when someone has the same prejudices as you do.

The use of diamond for diaphragms is mainly a sales gimmick that allows them to charge a huge premium. They probably ARE very good. But they are polycrystalline diamond not single crystal like the wifes engagement ring. So although they are probably quite strong and stiff they would likely crack earlier than a single crystal diamond would. The process is being industrialized for chip substrates because diamond is very thermally conductive. (Hence being called ICE) They do have mid range sized drivers. Very expensive. But the price of these should come down to synthetic corundum levels. Eventually

There are also tweeters (but no dome midranges that I know of) made with corundum which is the mineral species that with coloration makes ruby and sapphires. It also is quite strong and stiff. Tang band corundum tweeters are about $60 from parts express and are quite tempting to me.
Parts express also has some ceramic tweeters which probably have similar characteristics. I would go for these if I couldn't get a beryllium offering.
But there is nothing in the Midrange size range.
https://www.parts-express.com/speak...s-tweeters/tweeters/tweetertype/Corundum-Dome
https://www.parts-express.com/Tang-Band-25-1719S-1-Ceramic-Dome-Tweeter-264-865

I want to build a center channel that matches the Left and Right as depicted in my avatar and about me. I have managed to find two more NS500 tweeters to go with the two (extry ones) I already had and so far one only 88mm midrange. But it is easier to buy a used pair of NS1000M than to buy some of the above mentioned things. Which are not only rare but expensive and hard to source.

I was watching on fleabay a replacement part CMMD revel midrange. The seller was extremely proud of it. Too much so. I think I could easily buy a whole NS1000M for what was asked.

 

[Frank Dernie]

Perhaps that is why Yamaha uses Zylon treated with Monel.
Zylon has a 20% better weight to stiffness ratio than beryllium.
But really the main advantage of using Zylon is that all three drivers can be made from the same material .Which should bring gains in terms of driver integration.Some companies like Focal have done that with Kevlar but Zylon would appear to be a superior material to Kevlar or carbon.ISo perhaps it would be fair to claim that Zylon is the best possible material to use if you are wanting to use the same material for all drivers. Have you ever seen a 12 inch pure beryllium woofer?

Why would using the same material for all 3 drivers, apart from them all looking the same colour, be important?

Once you are using a fibre reinforced matrix the fibre, be it glass, carbon, kevlar, flax or zylon is just one (albeit very important) part effecting the mechanical properties.

It isn't the material you are listening to (unless the cone is breaking up) but the driver's ability to accurately reproduce the signal being applied to its motor system. The material the diaphragm is made from is only one aspect of that.

 

[thewas]

I don't think a hunk of beryllium could be put in a press and squished out to that size without deformation and other issues. That's how Focal makes their tweeter. In a press between dies.

Yes, Yamaha had to do a lot of effort in the 70s for their Beryllium membranes, namely vapour coat them on a copper dome which they afterwards etched away.

 

[jtgofish]

Why would using the same material for all 3 drivers, apart from them all looking the same colour, be important?

Once you are using a fibre reinforced matrix the fibre, be it glass, carbon, kevlar, flax or zylon is just one (albeit very important) part effecting the mechanical properties.

It isn't the material you are listening to (unless the cone is breaking up) but the driver's ability to accurately reproduce the signal being applied to its motor system. The material the diaphragm is made from is only one aspect of that.

Yes and a steel car which weighs 1600kg going 109.6 km an hour and which drives into a huge stationary steel pipe weighing 9256 kg will make exactly the same noise as a carbon fibre car weighing the same amount as the steel one and going the same speed running into an immobile giant custard pudding also weighing 9256kg.I am sure Peter Cook and Dudley Moore discussed this very thing.

 

[More Dynamics Please]

Perhaps that is why Yamaha uses Zylon treated with Monel.
Zylon has a 20% better weight to stiffness ratio than beryllium.
But really the main advantage of using Zylon is that all three drivers can be made from the same material .Which should bring gains in terms of driver integration.Some companies like Focal have done that with Kevlar but Zylon would appear to be a superior material to Kevlar or carbon.ISo perhaps it would be fair to claim that Zylon is the best possible material to use if you are wanting to use the same material for all drivers. Have you ever seen a 12 inch pure beryllium woofer?

That's a more reasonable claim to make though Zylon would need to be tested against all other available materials to validate. In the absence of definitive proof it would be more accurate to say that Zylon is one of the best materials to use if wanting to use the same material for all drivers.

 

[Frank Dernie]

Yes and a steel car which weighs 1600kg going 109.6 km an hour and which drives into a huge stationary steel pipe weighing 9256 kg will make exactly the same noise as a carbon fibre car weighing the same amount as the steel one and going the same speed running into an immobile giant custard pudding also weighing 9256kg.I am sure Peter Cook and Dudley Moore discussed this very thing.

No it won't.
The sounds will be different
The point is a speaker isn't making a sound by impacts causing its cone structure to ring.

Properly designed the cone will act as a piston. If it does resonate, like paper and plastic do, damping will be applied to reduce the colouration.

It is important to understand that in a speaker you are not listening to somebody using the cones as percussion instruments but, ideally, the cone does not breakup in its passband so that any characteristic sound the material would have won't be part of the sound coming from the speaker.

There seems to be a huge number of enthusiasts who haven't understood this.
I hope I have explained it adequately.

 

[Coach_Kaarlo]

No it won't.
The sounds will be different
The point is a speaker isn't making a sound by impacts causing its cone structure to ring.

Properly designed the cone will act as a piston. If it does resonate, like paper and plastic do, damping will be applied to reduce the colouration.

It is important to understand that in a speaker you are not listening to somebody using the cones as percussion instruments but, ideally, the cone does not breakup in its passband so that any characteristic sound the material would have won't be part of the sound coming from the speaker.

There seems to be a huge number of enthusiasts who haven't understood this.
I hope I have explained it adequately.

@Frank Dernie I love your engineering logic and reason. And the materials discussion. I wonder if we are missing something however - which is related to the information we are using to discuss the topic.

To the best of my knowledge no-one has material data or measurement data for the new Yamaha drivers. Or if they do they have not shared it. So we are guessing and speculating. They are a composite and therefore the exact composition matters, as does the process. Pre-preg does not have the same material properties of carbon strands - to use your example.

Interesting that on one hand most people who are aware of, and have listened to (or even measured them), have found the 1970's Yamaha beryllium drivers superior in many ways. Even compared to modern drivers. Yet also most seem unable to understand why that is / was. It was only partly the material - the technology, design execution, and manufacturing were a huge part.

I think Yamaha have access to resources and technology many (most) others driver or speaker manufacturers do not - there was no-one on the planet who could make Beryllium domes close to the Yamaha methodology or result. Most use cheaper or compromised methods which result in heavier or lower quality domes.

While I think it is too early to judge the Zylon / Monel composite (as we have no real data), the speakers which use this composite once again have incredibly low distortion at very high levels (I have tested / listened to them and would say they are comparable or better than the NS2K's I owned). My view is that the future of materials is composites, and the cynic in me thinks the same proportion of the population are always early adopters and laggards - it's been 50 years since the Yamaha Beryllium exercise, maybe in 2070 we will understand what they were up to with Zylon / Monel and how they executed it.......unless someone buys a pair of the speakers and actually measures them before then......

 

[gene_stl]

I don't see much point at all , to trying to make all the driver cones/domes/whatever out of the same material.

My first job out of university was at a Materials Research Lab. I like Yamaha stuff generally, and I also like composite materials, but I still think I would pass on a composite that needed to be coated with Monel to survive. And what's with the little trombones on the back of the drivers?

 

[jtgofish]

Perhaps just perhaps Yamaha being manufacturers of some of the worlds best musical instruments and state of the art motorcycles might have some insight into materials and their application?
Has anybody here even heard the NS5000s?I have.

 

[Doodski]

Perhaps just perhaps Yamaha being manufacturers of some of the worlds best musical instruments and state of the art motorcycles might have some insight into materials and their application?
Has anybody here even heard the NS5000s?I have.

Wowowow. NS-5000 is $20K in Canada. They sure do look nice.