[Danny Richie]

See recent comparisons of similar drivers:

http://www.zaphaudio.com/nondomes/

Here is some of the meat of it:

Aurum Cantus G3Si ($213) - Of the three true ribbons, the G3Si has the best low end performance. This isn't saying much since low end distortion is still horrible by dome standards. High tall order harmonic distortion, which is more evident in the single tone spectrum plots. Poor vertical off axis response.

LCY 130 ($199) - Very low sensitivity. Excellent vertical off axis response. Very close in on-axis performance to the Fountek, but at a much higher price.

Fountek NeoCD2.0 ($118) - Comparitively durable ribbon element. Of the three true ribbons, this has the best performance above 4kHz. It has the worst performance at 2kHz, rendered somewhat irrelevant because they are all terrible at 2Khz. It's excellent 4kHz+ performance is more obvious in the HD sweeps than the single and multitone spectrums however. Smooth response curve. Poor vertical off axis response.

Bohlender Graebener Neo3 PDR ($55 w/flange) - This B&G tweeter outperformed everything here, in most cases by a large margin. Response curve is ok, but linear and nonlinear distortion is excellent. This is a very clean and natural sounding tweeter.

Silver Flute YAG20-1 ($40) - Every test has to have a loser. This is it. Fairly flat and controlled response, but the distortion kills it.

Vifa D26NC55 ($29) - This cheap little dome tweeter outperforms everything here except for the B&G Neo3 PDR. It works well at 2kHz like the B&G, but has ever so slightly higher HD everywhere else.
Summary

None of the three true ribbons have very distinguished performance. They are more similar than different. But if I had to choose one, it would probably be the Fountek NeoCD2.0 because of it's durable ribbon, smooth response and clean top end performance. I'm not sure if I could live with that vertical off axis response. Generally, these ribbons do not live up to their price and hype. This point is driven home by their comparison to the cheap little Vifa neo dome.

None of the true ribbons should be used below 2.5kHz. The higher you cross them, the better you will avoid low end distortion. On the other hand, these are all large flanged tweeters, and as you cross higher, lobing at Fc becomes worse.

I often hear people babble on about the shimmer, sparkle and air of ribbon tweeters. These tests show where these "special effects" are coming from - distortion. This revelation isn't going to sit well with those who spent big money on ribbons with expectations or false beliefs that they are the best performers. What can I say except that I call them like I see (and hear) them.

The B&G and Silver Flute are both planar designs, but they are also polar opposites. The YAG20 is probably one of the worst performers I've ever seen, while the B&G performs on level with the best domes. It's hard to say what went wrong and what went right in their designs.

Folks, we have a winner - The Bohlender Graebener Neo3 PDR.

It also has a new face plate.  



You can order them straight from our web site here:

http://www.gr-research.com/drivers/bg_planar.htm

[jonwb]

Interesting discussion Danny... amazing how different implimentations of similar technologies can sound (well) so different.

Bohlender Graebener Neo3 PDR... This is a very clean and natural sounding tweeter.

Although my Alphas have the NEO8's instead of the 3PDR, I'd have to say your statement above most closely captures what I like most about the B&G tweeters.  Clear and clean... very fast and natural sounding.

Do you think a center channel w/ a NEO3PDR would have similar "voicing" to the Alphas?

[Danny Richie]

Actually those words were not mine but the guy that tested them.

Yes, the Neo 3 and Neo 8 do have a similar sound and the use of one in a center channel would match your Alpha's pretty well.

[Jon L]

I'm glad to hear Neo provides great value.  We need more of these types of drivers out there.  

But Mr. Krutke is basing his article on mounting tweeters on a baffle, measuring them, and I guess listening to the test tones.  

It is well-known that true ribbons are very finicky and tricky to work with.  It's very true they need to be crossed-over higher and given great crossover networks that require lots of tweaking.  IMHO, the great speaker designers can pull together fantastic-sounding speakers even with these poor ribbons

 

[brj]

Ok, I only had time to do a quick scan of the article, but... why do they all (including the dome tweeter) have spikes at 2 kHz?

The statement that the Vifa dome "works well at 2kHz like the B&G" seems out of place to me because they all appear to have issues at 2 kHz.  (Nice decay plot for the BG, however, although I wish they would add the Vifa decay plot for comparison.)

Too bad they didn't include the Aurum Cantus G2 ribbon, since many manufacturers on AC seem to use it or a derivation of it....

Some additional questions:

1) Can I assume that the decay plots directly map to what people consider the "speed" of a driver?

2) Can I assume that the red line at -40 dB on the HD plots represents the limit of audibility?

Thanks!

[Watson]

Ok, I only had time to do a quick scan of the article, but... why do they all (including the dome tweeter) have spikes at 2 kHz?

The statement that the Vifa dome "works well at 2kHz like the B&G" seems out of place to me because they all appear to have issues at 2 kHz.  (Nice decay plot for the BG, however, although I wish they would add the Vifa decay plot for comparison.)

Spikes in what?  If you mean distortion, that's because all of these tweeters are approaching their lower limit of operation around 2kHz.  The BG Neo3 PDR actually does quite well towards the lower end compared to the others.  You could probably cross it at 2kHz using a 4th order crossover.  Many of the others would have to be crossed higher.

[kfr01]

I'm glad to hear Neo provides great value.  We need more of these types of drivers out there.  

But Mr. Krutke is basing his article on mounting tweeters on a baffle, measuring them, and I guess listening to the test tones.  

It is well-known that true ribbons are very finicky and tricky to work with.  It's very true they need to be crossed-over higher and given great crossover networks that require lots of tweaking.  IMHO, the great speaker designers can pull together fantastic-sounding speakers even with these poor ribbons

 

I don't think Mr. Krutke would argue that "great speaker designers can pull" good sounding ribbon systems.  Experienced designers CAN make anything sound good.  

I think his point is this:  Based on John's widely accepted methods of testing speakers, it is less likely that a DIYer will be able to create a great sounding speaker with most ribbons.  Given their high price, most DIYers will probably be better off with even cheap soft dome tweeters.

His logic seems pretty defensible to me.

[kfr01]

Ok, I only had time to do a quick scan of the article, but... why do they all (including the dome tweeter) have spikes at 2 kHz?

You should have scanned a little more carefully.  

The tests included single and multiple test tones at 2khz and 4khz.  i.e., the spike at 2khz is supposed to be there.

F1 is the fundamental frequency (the actual test tone).  F2-F5 are the harmonics.  Those are the other tall spikes on the graphs.  See this page for a basic explanation of fundamental frequencies and harmonics. :http://ccms.ntu.edu.tw/~karchung/phonetics%20II%20page%20eight.htm

What you should be looking at is the relative height of all the other green information, including the harmonics, relative to the height of the fundamental.  The lower the better.  For example, see how all the other green information on the Neo3PDR - Single Tone Spectrum, 2000 Hz graph is much lower, relative to the 2khz test tone, than the information of the other tweeters.  The program summarizes this for you in the THD number.

John called the BG the winner because its distortion was lower than the others, even if the frequency response graph was average.  He weighted his test this way because frequency response issues are relatively easy to handle at the crossover design stage.  There isn't much you can do about distortion above your desired crossover point.

Hope this helps.

[Danny Richie]

IMHO, the great speaker designers can pull together fantastic-sounding speakers even with these poor ribbons

I have worked with them a lot and have to agree. I also find they need little tweaking and are not that hard to work with, but they can not be allowed to play down too low. I wouldn't want to try to calculate something or design anything for them without measuring equipment. They are not friendly to the hobbyist in that way.

1) Can I assume that the decay plots directly map to what people consider the "speed" of a driver?

Yep. How quickly a driver bleeds off stored energy and inertia is often what people refer to when they talk about driver speed.

I wish he would have posted the spectral decay of the dome tweeter as well. Since they have much higher mass than the others it is typically not as good.

2) Can I assume that the red line at -40 dB on the HD plots represents the limit of audibility?

You may not be able to hear the 2nd and 3rd harmonics with the low wattage test signal (typically 1 watt or less), but increase the power on them (10, 20, 40, 80 watts...) and then see what you hear.

Oh, and I have crossed Neo 3's as low as 1,500Hz with no problems at all.

[brj]

You should have scanned a little more carefully.  

The tests included single and multiple test tones at 2khz and 4khz.  i.e., the spike at 2khz is supposed to be there.

That's what I get for trying to scan and post as I was running out the door...

Thanks to you and Danny for the clarifications!

[Kevin Haskins]

That looks like a great unit Danny.    I like the wide dispersion and it looks like it's fantastic tweeter from the distortion measurements.   Damn good...

Also... it doesn't have the issues with being as fragile as a ribbon.   Heck... I'd even use one of those.     The price is certainly reasonable considering the performance.   It would even cross fairly low without any problems.    No wonder you have been using them for the last couple years!  

[Aether Audio]

Danny,

I often hear people babble on about the shimmer, sparkle and air of ribbon tweeters. These tests show where these "special effects" are coming from - distortion. This revelation isn't going to sit well with those who spent big money on ribbons with expectations or false beliefs that they are the best performers.

Hmm...Recently I've been hearing comments about my little ScanSpeak 9300 sounding "soft" in the highest registers.  Actually, it's a 180 degree "about face" from the original tweeter I was using - but that's besides the point.  

There's an upcoming review on our Continuum A.D.MKII's from a beloved AC member that I believe will be making that very claim even.  Aparently it doesn't seem to have as much "air" and detail as was expected.

I wonder.   Do ya think...maybe...?

Very interesting bit of data there Danny.  Thank you.  Education is a wonderful thing.

-Bob

[Danny Richie]

Aparently it doesn't seem to have as much "air" and detail as was expected.

He must have been using them with those little Black boxed chip amps that have become popular lately.  

I thought they sounded GREAT!

[Aether Audio]

Danny,

No, not at all.  In fact, he's using what appears to be excellent equipment.  Don't get me wrong either, as far as this one goes, I don't believe they get any better whatsoever - and to be honest I'm thrilled.  

The detail/air thing was the only (very mild) criticism and the reviewer even questioned his own expectations.  That's why I brought it up here.  This guy is VERY bright.  He actually suspected that it might not be a fault of the tweeter.  Very few people have the insight to be that observent.  And I'm not just saying that because it was one of our products.  I'm interested in the science.  I want to know why things sound the way they do.  That's how one makes better products - not by defending them.

It's my suspision that it's the extremely low distortion of the tweeter/waveguide system that leads to the "soft," less detailed sound.  Most people are so used to listening to so much H.F distortion, they think that if it's missing, there's something wrong.  I can't argue that there are those that may like the effect, but then we're getting into euphonia and I don't know how (well, actually I do) to do that.  Let's put it this way.  I don't want to do that - not in a product that is advertized to be a reference monitoring design.

But what folks like is what they like and there is no right or wrong there.  It would be nice though if they KNEW why they like what they do.  It would sure take a lot of the snake oil out of this business.

-Bob

[kfr01]

That looks like a great unit Danny.    I like the wide dispersion and it looks like it's fantastic tweeter from the distortion measurements.   Damn good...

Also... it doesn't have the issues with being as fragile as a ribbon.   Heck... I'd even use one of those.     The price is certainly reasonable considering the performance.   It would even cross fairly low without any problems.    No wonder you have been using them for the last couple years!  

Is this some sort of hint at a future Exodus Audio product?

[jackman]

Great thread Danny.  John Krutke is a good guy, with a very solid and streightforward approach.  With all of the miracle clocks, magic rocks and unfounded claims that are too common in this hobby (OK, obsession or at least compulsion), it's good to know there are still people who believe in real science.  

Those little BG's look very impressive.

J

[Danny Richie]

No, not at all. In fact, he's using what appears to be excellent equipment.

Oh I was just kidding you about those amps again and not really questioning the reviewer.

[Kevin Haskins]

That looks like a great unit Danny.    I like the wide dispersion and it looks like it's fantastic tweeter from the distortion measurements.   Damn good...

Also... it doesn't have the issues with being as fragile as a ribbon.   Heck... I'd even use one of those.     The price is certainly reasonable considering the performance.   It would even cross fairly low without any problems.    No wonder you have been using them for the last couple years!  

Is this some sort of hint at a future Exodus Audio product?

Nope...  Wiggins has used them in a Dipole design though and mentioned to me months ago how good they measure.    I'll pick up a pair to try though....nothing ventured nothing gained.    They overcome my biggest objection to ribbons (although they are not a ribbon) and they have excellent off-axis performance.

[Kevin Haskins]

No, not at all. In fact, he's using what appears to be excellent equipment.

Oh I was just kidding you about those amps again and not really questioning the reviewer.

I did a PCB for one of those little chip amp designs.  

It sounds pretty good for $30 in parts.   Not a giant killer but it was good enough we used it for the last speaker event.  

The Hypex units beat them fairly easy though.

[kfr01]

It was mentioned, so I thought I'd provide the link.  Adire's dipole design using the BG Neo 3 and 2 Extremis 7" drivers can be found for free, including crossover design, at the following link:

http://www.adireaudio.com/Home/KITDDR.htm