beryllium diaphragm VS titanium diaphragm

someone says that beryllium diaphragm is better than titanium and make sound cleaner and better but i think this is marketing becase is expensive product. So after some research i found audioexpress page showing Radian 745NeoBe that 118 - 120 db produce 60 - 65 db 3ed harmonic distortion and B&C De980NT-8 WITH 118 - 120 db produce 45 - 50 db 3ed harmonic distortion and also higher frequency extension.

Also you will never see any Top brand use beryllium as L Acustics (Which has excellent sound and not even high presure levels distortion or harash sound...)
 
It's about Physics. Beryllium is lighter and stiffer then any of the common diaphragm materials. I have and use both beryllium and aluminums and can say beryllium is the best (but expensive ) sounding in my compression driver horn system. Titanium annoys my ears !!! My personal experience in my system and 2 cents worth.
 
Beryllium is technically better. Titanium gets its upper output from diaphragm breakup. Beryllium stays pistonic throughout the same range giving the impression of less extentsion when in reality it's capable of tracking the signal much more accurately when eq is applied.
 
There are good and bad titanium drivers.
I own Yamaha NS75Ts speakers which use titanium mids and tweeters and have also used Yamaha NS1000s that use beryllium mids and tweeters.The NS 75Ts [titanium] sound much better.
Some of the JBL titanium tweeters also sounded excellent.
 
this graph is old
Figure3FrequencyResponseandHarmonicDistortion.jpg

In our days mesurments shows other wach Radian 745NeoBe VS B&C De980NT-8 audioexpress Bench Test Tehnology of new titanium diaphragms are much better

Radian
Figure9-RadianAudio745NEOBe.jpg

B&C
Figure8-BnC-DE980TN-8CompressionDrvr.jpg

After 8khz B&C distrotion rised slightly but even so in top end they gonna have about same distortion & down than 10-12 KHZ lower distortion. There are many parametres for a good driver and not only diaphfragm.
 
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I was given a tour of the Harmon works back in the 90’s by the engineer who developed their titanium driver for their compression speakers . In his lab they had a beryllium cp, I think made by matsushita. He said it was outstanding and set the bar on performance. I asked why they didn’t just use beryllium and he said the lawyers wouldn’t allow it. If it shatters, it is poisonous or something like that.

Beryllium is superior because it’s lighter and stronger. When a driver moves, parts of it actually are moving backwards. On their computer, you could see this, parts zigging when they should be zagging. This causes cancellation. Of course, you could make the driver thicker to reduce that but hey, there goes response.

You can see how, when it comes to conventional speakers, berylium is the best Material .
 
someone says that beryllium diaphragm is better than titanium and make sound cleaner and better but i think this is marketing becase is expensive product. So after some research i found audioexpress page showing Radian 745NeoBe that 118 - 120 db produce 60 - 65 db 3ed harmonic distortion and B&C De980NT-8 WITH 118 - 120 db produce 45 - 50 db 3ed harmonic distortion and also higher frequency extension.

Also you will never see any Top brand use beryllium as L Acustics (Which has excellent sound and not even high presure levels distortion or harash sound...)

Are those drive units identical in every single respect other than the diaphragm material (including profile, thickness &c.)? If they aren't, your comparison is utterly worthless, since you have changed almost every single variable and haven't the first idea where and what causes the differences in performance.

Beryllium is technically superior to titanium for the reasons mentioned above: it has a higher stiffness / weight ratio, which when used optimally, allows a wider pistonic BW and potentially higher SPLs under otherwise identical conditions. So from that perspective, it doesn't make the slightest difference whether you think it is all marketing, because the laws of physics and engineering have rather obvious reasons for using it. Whether the implementation is of sufficient quality to exploit these potential advantages is another (separate) question: that is a matter of driver design.
 
There are so many other factors than dome material that I find this difficult.

But here are the two 34mm BlieSMA tweeters that are exciting people. Slightly different dome profiles, the AL being more rounded.

Beryllium gains on the higher first resonance at 32kHz rather than 27kHz and 1.5dB more efficiency. The frequency response and off-axis dispersion looks more a function of dome profile.

But not the smoking gun to say expensive and toxic beryllium is a compelling buy IMO. Titanium has its uses too, it is tougher for high power applications apparently.

SB Acoustics are doing interesting things with anodised Aluminium, which they call ceramic, and diffusors and flatter profiles which look good at the price too. But really, what's not to like about the affordable 1" SB26ADC?

All three illustrations are non-ferrofluid designs, BTW.
 

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Are those drive units identical in every single respect other than the diaphragm material (including profile, thickness &c.)? If they aren't, your comparison is utterly worthless, since you have changed almost every single variable and haven't the first idea where and what causes the differences in performance.

Beryllium is technically superior to titanium for the reasons mentioned above: it has a higher stiffness / weight ratio, which when used optimally, allows a wider pistonic BW and potentially higher SPLs under otherwise identical conditions. So from that perspective, it doesn't make the slightest difference whether you think it is all marketing, because the laws of physics and engineering have rather obvious reasons for using it. Whether the implementation is of sufficient quality to exploit these potential advantages is another (separate) question: that is a matter of driver design.
Thank you Scottmoose so end of story beryllium is higher than titanium but it doesnt mean that a titanium driver is not better than a beryllium driver... Must be all parametres of a driver the same to say that a beryllium is better.
 
Does Scottmoose or anyone understand why some metal dome tweeters are described as having a break up that is ultrasonic, such a this one

SEAS Prestige 27TBFC/G (H1212) Aluminum/Magnesium Dome Tweeter

Then what is the point of a beryllium tweeter if an aluminum dome can be made that breaks up outside our range? The FR of the aluminum dome doesn't look all that flat. Are there eariier mini break ups in the aluminum.

Will the aluminum dome still sound metallic. I associate a metallic sound with metal cone break up.
 
Does Scottmoose or anyone understand why some metal dome tweeters are described as having a break up that is ultrasonic...

Yes, it's simply because the main bell mode is above the nominal maximum 20KHz HF limit of human hearing.

Then what is the point of a beryllium tweeter if an aluminum dome can be made that breaks up outside our range? The FR of the aluminum dome doesn't look all that flat. Are there eariier mini break ups in the aluminum.

There are three points there. Last first: not unless there are. ;) Not every aluminium dome tweeter of a given size behaves the same way. In the case of the Seas you link to, no. Again, using the 27TBFC/G, it looks pretty flat to me. Ruler flat from ~2KHz - c.14KHz. Not bad. The rolloff above that is due to the mass (the Seas is an aluminium / magnesium alloy BTW) until you hit its main resonant mode.

What is the point? Two reasons really. Firstly, lower mass, so potentially (note caveat: this is not a given) the Be dome can remain flatter at the top end of the nominal audio BW. Secondly, distortion. There is the potential for increased IM distortion in the audio band if a bell mode above it gets excited. Having a greater stiffness - weight ratio, Be can allow this bell mode to be shunted to a significantly higher frequecy, where it is less likely to be excited & amplify distortion lower down the range. The audibility of this is debated; for whatever my view is worth (nothing) I do not see it as a black / white matter but an interesting point worth keeping in mind, but which is likely to depend on circumstance (not least motor & suspension design, frequency, mode Q & other factors). Direct comparisons are difficult since there are few tweeters that are identical in all respects other than having, say, an alluminium or Be dome material.

Will the aluminum dome still sound metallic. I associate a metallic sound with metal cone break up.

It also depends what you call a 'metallic sound'. If a driver is not in break up in the audio band (or it is heavily suppressed), you aren't hearing breakup. QED. You may however have distortion issues connected with it elsewhere. Depends on the driver. Most people love that Seas tweeter for e.g.; some hate it. I suspect a portion of those who hate it are listening with their eyes & are uneasy about that ~27KHz bell mode, but I wouldn't casually discount the potential for it to cause audible issues for some people either under certain conditions. YMMV.
 
IMHO, the magic is in the waterfall plots, compression and FR

Regardless of technology, my ears prefer the smoothest FR and lowest stored energy in the audible range, along with a lack of compression throughout my listening range.

I agree with this. In the same vein, the best overall non hornloaded tweeter I've heard is a compression driver with no horn. There are tweeters that are slightly smoother and extend higher but the headroom and low frequency capabilities can't be compared.
 
Does Scottmoose or anyone understand why some metal dome tweeters are described as having a break up that is ultrasonic, such a this one

SEAS Prestige 27TBFC/G (H1212) Aluminum/Magnesium Dome Tweeter

Then what is the point of a beryllium tweeter if an aluminum dome can be made that breaks up outside our range? The FR of the aluminum dome doesn't look all that flat. Are there eariier mini break ups in the aluminum.

Will the aluminum dome still sound metallic. I associate a metallic sound with metal cone break up.

A 3/4" or 1" aluminum dome can push the break up peak above 15khz.

The advantage of beryllium is that you can have a dome as large as 2-3" in diameter, and the peak is still ultrasonic.

That's why Be is popular in compression drivers, but not so much in HiFi dome tweeters.
 
Thanks Scottmoose and everyone for all the replies. I've tried to equalize out metal cone break up in drivers (not tweeters though) and it seems like the metallic sound remains especially if you learn to identify it. I think its a bit like trying to hammer a dent out on a car. Its gets better but you can still see it.

It sounds like some metal tweeters might actually have the rigidity without the metal sound. Never heard a beryllium driver though.
 
A tweeter is a rather different matter to a midbass or similar. EQing a major bell mode flat (or even applying a high Q notch alone) isn't going to help. The distortion lower down the range, which is what you are likely hearing, is still present. If you want to prevent that, you need to heavily suppress the bell / resonant modes, not just flatten them out. That really means high order crossovers well below the first mode (depending on order, 1 - 2 octaves below).
 
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Beryllium is technically better. Titanium gets its upper output from diaphragm breakup. Beryllium stays pistonic throughout the same range giving the impression of less extentsion when in reality it's capable of tracking the signal much more accurately when eq is applied.
Beryllium is technically superior to titanium for the reasons mentioned above: it has a higher stiffness / weight ratio, which when used optimally, allows a wider pistonic BW and potentially higher SPLs under otherwise identical conditions.
A 3/4" or 1" aluminum dome can push the break up peak above 15khz.

The advantage of beryllium is that you can have a dome as large as 2-3" in diameter, and the peak is still ultrasonic.

That's why Be is popular in compression drivers, but not so much in HiFi dome tweeters.

Whether the implementation is of sufficient quality to exploit these potential advantages is another (separate) question: that is a matter of driver design.

Might anyone here have heard a beryllium driver like the Radian 745neoBe in a two way system? If yes, might it have been used with a horn similar to the TAD or Athos 4001? If yes, were you satisfied with how the EQ for this driver was optimized? Did the 4001 horns have vanes or not? Please describe your listening observations.
 
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