How much impact does driver material actually make?

[infinitesymphony]

Just reporting what I found when I looked up Zylon. Seems like it's being used as a kevlar and carbon fiber replacement (vests, bike and auto parts), but there are questions about durability when exposed to sunlight and humidity.

 

[Harmonie]

Just reporting what I found when I looked up Zylon. Seems like it's being used as a kevlar and carbon fiber replacement (vests, bike and auto parts), but there are questions about durability when exposed to sunlight and humidity.

Seems that you are not in that biz then, I'm relieved
Any advanced fiber's tensile strength weakens under light (not UV, not sunlight, any visible light). Zylon more than others.
But it's initial strength is way above others.
But as @Frank Dernie indicated, the cones do not need more strength, but better damping and stiffness., so no correlation to light.

 

[tvrgeek]

PSP made a concave tweeter. All kinds of claims. Decent, but not revolutionary. Some woofers have concave dust caps. A concave cap, or entire dome requires a longer former to clear the pole piece, so more mass. Basically not a good idea.

The plasma speakers were actually a disaster. Who wants to fill their house with natural gas or ozone, or whatever they used. I guess some used helium. Some have suggested Corona effect, but the amount of ozone they produce is lethal.

There is a reason almost all speakers are conventional dynamic drivers. They work pretty well. ES have advantages, but many disadvantages. Planers, AMT, ribbons and so on. Bottom line is they just don't work overall as well. I would argue with the advantage of 360 degree radiation as it is the near reflections that mess up the imaging. Even bi-polar and di-polar have to have a lot of space around them or they sound pretty terrible. Minimum 2 feet clear from anything. I remember Heil dealers had to make a special show room to demonstrate theirs.

 

[mhardy6647]

I took the grille off one of my little Klipsch Promedia's one day and found one of the dust covers had been pushed in but i'm very careful with my toys and don't drink a lot or do a lot of drugs yet I had zero recollection of this happening so my mind was blown. Even though I knew it made no difference to the sound, it just looked bad so I pushed the other one in to at least make them look the same but since it makes no difference to the sound why don't all speakers just come with convex dust caps? Voila! Problem solved. I started watching the video on how to fix them but any video that starts off by telling you that you need "duck tape" is hard to take seriously

Duck Tape is a thing.

 

[mhardy6647]

The EPI/Epicure concave dome tweeters of the 1970s were quite nice (still are, to my ear).

EPIsprings by Mark Hardy, on Flickr

Electrovoice sold the DuKane Ionovac plasma tweeter (as the EV T3500) a long time ago (late 1950s). I think the horn was made by EV. These also make ozone, but not too much. Very sweet sounding but seriously low sensitivity.
https://products.electrovoice.com//binary/T-3500%20Ionovac%20EDS.pdf
http://www.roger-russell.com/ionovac/ionovac.htm

The Hill Plasmatronics speakers used helium for the plasma to sidestep the ozone issue.

 

[aarons915]

Dr. Toole has made comments before about how people hear "metallic" or silky sounding tweeters based on the material during sighted sessions and those characteristics disappear during blind listening sessions. Based on that I still believe that the frequency response and directivity are what really matter.

 

[carewser]

I don't know if you are in this biz and what you are trying to demonstrate, but you can't really compare material for Hifi use and bullet proof jackets

Yes you can and I already did by saying that if someone comes at me with a gun i'll put up my kevlar woofers to protect me

 

[Inner Space]

Duck Tape is a thing.

View attachment 91724

The original duck tape was an inch or more wide, made of a tough cotton weave known as "duck". Your great-grandma had it on her venetian blinds. Then came duct tape, borrowed from the HVAC business. This new Duck tape is just an inspired brand name - but kind of full circle.

 

[Coach_Kaarlo]

Just reporting what I found when I looked up Zylon. Seems like it's being used as a kevlar and carbon fiber replacement (vests, bike and auto parts), but there are questions about durability when exposed to sunlight and humidity.

Mate, Zylon is used in yacht rigging and F1 wheel tethers - components which see just a little light......


Yamaha actually coat the Zylon weave in Monel, widely known and used for its corrosion resistance properties.

https://en.wikipedia.org/wiki/Monel

https://en.wikipedia.org/wiki/Zylon

https://www.toyobo-global.com/seihin/kc/pbo/zylon-p/bussei-p/technical.pdf

These guys spent 8 years developing this speaker design, perhaps you could / would expect they considered some of these simple driver cone material issues before releasing the final product. The world is full of people who do not understand the engineering behind the products they use every day - doesn't prevent the enjoyment in the use of these products - nor does it mean those with far greater knowledge haven't already solved problems we are not even cognisant of either.

Physics, and material science matter more than many realise. As do the mode shapes generated in the driver material during operation. Stiffness is king, low mass is king, high internal damping is king.

[Edit: I have designed 60,000kg machines which vibrate at 1,000Hz with 6g of alternating acceleration, so I understand some of the fundamental physics a little - very difficult to balance strength, stiffness, fatigue life, and mode shapes with natural resonant frequency (breakup freq.)]

 

[infinitesymphony]

Thank you for the info @Coach_Kaarlo. As far as I can tell, Yamaha are the only speaker company attempting to use Zylon in the almost 20 years since it was released. In every case you mentioned and more -- yachting, F1, table tennis rackets, speakers -- steps have been taken to encase the Zylon in another material (epoxy, synthetic jacket, etc.) so that it is not exposed to UV radiation or moisture. Do you think these considerations have prevented others from using the material, or are cost and availability the more significant factors?

 

[mhardy6647]

speaking of driver materials -- I rather literally (OK... almost literally!) stumbled across this vintage ad in a when I was looking for info on the (somewhat) infamous Carver M-400 'Cube' amplifier I thought it was worth a drive-by here to share it as an historical (or hysterical, if you prefer) artifact. Note that it's a four-page (!) front-cover fold out spread -- so I cannot really do it justice with a cut-n-paste exercise.

https://worldradiohistory.com/Archi...iFI-Stereo/80s/HiFi-Stereo-Review-1980-10.pdf

 

[Pearljam5000]

Beryllium sounds different to me than other tweeter , i believe 100% that materials do make a big difference

 

[restorer-john]

but there are questions about durability when exposed to sunlight and humidity.

Maybe we'll be seeing Yamaha NS-5000s on kerbside rubbish pickups in 15 years.

 

[mhardy6647]

Maybe we'll be seeing Yamaha NS-5000s on kerbside rubbish pickups in 15 years.

It could happen -- although I've yet to find a pair of NS-1000s on the swap pile.
Yet.

I have found some pretty good things, though.

 

[Harmonie]

Thank you for the info @Coach_Kaarlo. As far as I can tell, Yamaha are the only speaker company attempting to use Zylon in the almost 20 years since it was released. In every case you mentioned and more -- yachting, F1, table tennis rackets, speakers -- steps have been taken to encase the Zylon in another material (epoxy, synthetic jacket, etc.) so that it is not exposed to UV radiation or moisture. Do you think these considerations have prevented others from using the material, or are cost and availability the more significant factors?

Not 100% sure, but I tend to remember that it was used for car speakers as well .
A significant factor is surely the cost; it ain't "cheap" and it's used when no alternative: like good properties with super-light material, or heat resistance or the "best" available.

 

[Coach_Kaarlo]

Not 100% sure, but I tend to remember that it was used for car speakers as well .
A significant factor is surely the cost; it ain't "cheap" and it's used when no alternative: like good properties with super-light material, or heat resistance or the "best" available.

Or someone did some research and solved some of the problems associated with the traditional application = all materials technology pretty much.

Carbon fibre for example ranges from cosmetic junk to the motorsport autoclaved components which are incredibly light, stiff, resilient, etc.

 

[valerianf]

About tweeter material, just listen a cymbal sound track: you will immediately recognize the aluminium dome material.
You get some harmonics that you will never have with a silk dome tweeter.
But for other instruments a silk dome tweeter sound better.
How does sound a beryllium tweeter?

 

[KeithPhantom]

About tweeter material, just listen a cymbal sound track: you will immediately recognize the aluminium dome material.
You get some harmonics that you will never have with a silk dome tweeter.
But for other instruments a silk dome tweeter sound better.
How does sound a beryllium tweeter?

To my ears it sounded the same as an aluminum one or even a paper one. It doesn't matter the material that much (unless is for a very specific reason), what matter is the implementation. If you can get a perfectly flat FR with a nice CSD and it sounds good, i don't care if you made the speaker out of toilet paper, it sounds and measured well.

 

[thewas]

I had written about the sound of different tweeters here, including scientific research with listening tests:

https://www.audiosciencereview.com/...rbeth-30-2-vs-kef-r3.14450/page-2#post-445233

Different sound is only due to different FR (which can be equalised), resonances & distortion (which can be made low enough to be inaudible) and due to differences in radiation pattern, no magic behind.

 

[sfdoddsy]

As evidenced by the various responses above, the obvious answer is that the material makes a difference how a driver behaves, but not whether that behaviour is good or bad.

I’ve owned and built speakers with drivers ranging from paper, to magnesium, to papyrus, to aluminium ribbons, to electrostatically charged plastic, to ceramic, to diamond, to the intestines of a ritually slaughtered goat.

In spite of their claims at the time, and my varying levels of enthusiasm, none are or were intrinsically better than another.

Berylium is the flavour of the month for tweeters, for example. Yet SB Acoustics lowly SB26AC measures better than their lofty SB29 Be.

KEF and Genelec aside, none of the top-rated speakers here have exotic or unusual drivers. The Revel M106uses quite ordinary SB Acoustics drivers. But it uses them well. The Ascend Sierra has exotic drivers yet doesn’t use them well.

There is a thread that is no doubt tripling as I type about the Purifi kit speaker. Whether it is because of shipping damage, poor design, poor execution, or wrath of the audio gods, the drivers come across as over-priced crap.

Yet if you read the equally well-conducted review from Erin of the Selah Purezza which uses the same driver and an alternative non-dome tweeter, the very same drivers come across as the second coming.

It is all about execution.