Soft vs Hard Dome Tweeters: Which do you prefer?

[AcuDefTechGuy]

I once heard two DIY 2-way speakers where both were nearly identical except for the tweeters. The mid-woofers, cabinets, and crossover frequencies were identical, but there were some smaller differences in shapes of the roll off curves required by each tweeter, in order to blend well with the mid-woofer.

One tweeter was fabric and the other was aluminum. While this was not a blind comparison, no one, among the 15 or 20 DIY speaker builders present, could tell the difference.

Too bad the comparison wasn't between a Diamond or Be tweeter vs Fabric & Al.

 

[KEW]

I believe the worst dome tweeters are metal. I also believe the best dome tweeters are metal.

A metal tweeter has the potential to be harsher than a soft-dome could ever be and would suggest avoiding cheap speakers with metal tweeters.

However, metal also has the potential to sound better if properly designed. I have to believe a soft dome has lots of extra "breakup" waves rippling across it's surface. It is, after all, fabric and you cannot expect it to stay as rigid between the motor and the surround as metal can. Fortunately, it never calls attention to itself the way a metal tweeter that breaks up inside the audible frequency range does.

I don't know every company that uses Be tweeters, but I have to believe there is a reason why it is the material of choice among manufactures such as Paradigm, Focal, TAD, and Status Acoustics for their premier product lines with domed tweeters.

The best "value" execution of a metal dome that I am aware of is the Energy RC-10 which goes for about $230/pair when on sale at Frys (about every 6 months, it seems). It is an aluminum dome, but is largely clean to my ear (as in I'm not sure I would hear the difference if I didn't have a good Be tweeter sitting next to it to compare it to).

 

[SurvivalDad]

I wish I could hear the difference, but I just can't. Too much volume as a younger man, I guess.

 

[AcuDefTechGuy]

I wish I could hear the difference, but I just can't. Too much volume as a younger man, I guess.

I doubt you're the only one who can't tell a significant difference.

The Bias Force is a strong with this one.

My hearing acuity is so good I could even tell you the make and model of the speaker just from hearing the tweeter.

Diamond has that crystal sound to it, while metal has that shiny sound to it.

Silk unequivocally has that soft warm sound to it.

I'm not really inebriated or mentally altered by psychotropic.

 

[Irvrobinson]

I don't know every company that uses Be tweeters, but I have to believe there is a reason why it is the material of choice among manufactures such as Paradigm, Focal, TAD, and Status Acoustics for their premier product lines with domed tweeters.

Harman provides their reasoning in the Ultima2 product brochure. See:

http://www.revelspeakers.com/tl_files/catalog//LuxuryCars/Revel/Manuals/Active/Ultima2/prod_145_634595542765965291_Revel Ultima2 Brochure.pdf

Pages 14-15. I think there's a lot more to designing a tweeter than choosing a cone material, but you really can't argue with Revel's results. I've also wondered how much that waveguide they use and the low-diffraction cabinet would make any dome tweeter sound better.

 

[Irvrobinson]

I'm not really inebriated or mentally altered by psychotropic.

I believe you, and that's the frightening part.

 

[KEW]

I think there's a lot more to designing a tweeter than choosing a cone ...

Oh, I didn't mean to suggest that the dome material was the only factor or even a major factor.

However, I'm thinking that measurements of distortion and impulse responses would show consistent differences between soft and Be. I also think some high resolution ultra slow motion photography to monitor dome distortions would be revealing.

 

[highfigh]

A "single-blinded study" means the subjects don't know which speaker they are listening to at any given moment. Double-blinded means neither the subject nor the administrator knows. They can SEE all they want.

As Swerd, 3dB, and others have said, it is difficult to just separate the tweeter. You are listening to the entire speaker. One way I think would help in the comparison is to remove the bass from the equation via subwoofers. But that would still leave you with the midrange and tweeter.

How do you remove the midrange from the equation and just compare the tweeter?

I know about single and double blind- just hadn't seen 'blinded' used in that context.

The thing that makes this difficult as a "hot swap" evaluation is that it takes time to notice all of the nuances, it requires good level-matching & crossover design and changing the level of just the tweeter can make the bass and mids sound completely different.

It's interesting that it can be difficult to hear a difference when the response, dispersion and crossover requirements vary so much

 

[highfigh]

And then, there's this-

http://www.audioholics.com/loudspeaker-design/loudspeaker-drivers/diaphragm-material

 

[Irvrobinson]

Oh, I didn't mean to suggest that the dome material was the only factor or even a major factor.

Yeah, I didn't mean to suggest that you thought about dome material that way, I was just thinking out loud.

 

[AcuDefTechGuy]

Oh, I didn't mean to suggest that the dome material was the only factor or even a major factor.

However, I'm thinking that measurements of distortion and impulse responses would show consistent differences between soft and Be. I also think some high resolution ultra slow motion photography to monitor dome distortions would be revealing.

It's easier to see the difference on paper (measurements). But if you're measuring the speaker, you are measuring the effect of the whole speaker. And, of course, measurements don't tell the whole story.

I don't think any Beryllium speakers measure more accurately than the KEF 201/2 (titanium tweeter) or the LS50 (aluminum tweeter).

I bet KEF could have used paper and the 201/2 and LS50 would still measure better than any Beryllium & Diamond tweeter speakers.

 

[KEW]

I bet KEF could have used paper and the 201/2 and LS50 would still measure better than any Beryllium & Diamond tweeter speakers.

Shhh! They've spent a small fortune developing their Aluminum driver technology. If management finds out they could get the same or better performance from paper, there's gonna be some 'splaining to do!

 

[Irvrobinson]

I bet KEF could have used paper and the 201/2 and LS50 would still measure better than any Beryllium & Diamond tweeter speakers.

Unfortunately, we'll never know. Paper would be a lot safer than beryllium, which is toxic. Beryllium dust is known to cause lung cancer, for example.

 

[rnatalli]

Most speakers I've preferred over the years used metal domes, but there are a few using soft domes that I've liked.

 

[KEW]

Unfortunately, we'll never know. Paper would be a lot safer than beryllium, which is toxic. Beryllium dust is known to cause lung cancer, for example.

Just to clarify, the real safety concern is in its manufacture where it is air born as dust that you can breath or absorb through skin.
I could take a chisel and shatter my Be tweeter, but it would end up in pieces that gravity would drop to the floor. Now, if I used a Dremel to grind it...

 

[Irvrobinson]

Just to clarify, the real safety concern is in its manufacture where it is air born as dust that you can breath or absorb through skin.
I could take a chisel and shatter my Be tweeter, but it would end up in pieces that gravity would drop to the floor. Now, if I used a Dremel to grind it...

I don't know how brittle Be is, but I'm guessing that if you shatter your Be tweeter there will be a bit of dust produced. I don't worry about it, but I'd walk away from the area of the broken tweeter for a while while you're sobbing from dismay, just to be sure.

 

[gene]

Unfortunately, we'll never know. Paper would be a lot safer than beryllium, which is toxic. Beryllium dust is known to cause lung cancer, for example.

Be is safe as long as you don't burn it. I suppose if your house goes on fire, you should get out before the tweeters burn up

 

[jcparks]

I loved the tweeter in my Vandersteen Model 3's. The Highs were transparent and silky smooth, however I get a similar effect from my Overnight sensations at a fraction of the price. I think the details are in the budget. If you have a big budget, a well designed metal dome is the way to go, however a soft dome is going to give you way more bang for the buck.

 

[KEW]

I loved the tweeter in my Vandersteen Model 3's. The Highs were transparent and silky smooth, however I get a similar effect from my Overnight sensations at a fraction of the price. I think the details are in the budget. If you have a big budget, a well designed metal dome is the way to go, however if you don't a soft dome is going to give you way more bang for the buck.

...and won't screw the pooch the way a poorly designed metal-dome can.

Finished it for you

 

[KEW]

Be is safe as long as you don't burn it. I suppose if your house goes on fire, you should get out before the tweeters burn up

If it is pure Be, burn temp is over 1100F, so as long as you get out before you burn up, you should be okay!

(but if it is a composite, the burn temperature could be much lower, depending on the other materials)