Let's talk Tweeters!

hi @timlub

My point, poorly made, was that the quality of the tweeter was pretty subjective, and I had not heard one that was so fantastic it would eliminate any other tweeter from consideration.

I consider the plasma tweeter revolutionary in terms of technology, not sound I'm afraid. 

You know guys, I've heard the meme that Plasma tweeters are the best in the world, but that's marketing hype. 

Of course, we can grant that the tweeters have immeasurable moving mass, but the novelty of the technology is not the same as the implementation. 

The measurements for the Lansch Audio 5.1 are not bad, in fact in some ways they are pretty commendable:

https://www.stereophile.com/content/lansche-audio-51-loudspeaker-measurements

But I wouldn't call the FR best in the world, and, oddly, there's some stored energy ringing happening near 20kHz. Maybe this is from the horn? 

Again, buy what you like, but I think that calling these the best in the world tweeters is a bit much. I think there are a number of dome's, ribbons and AMTs which would sound as good if not better to some. 

Best,

E

Tim:

I use much smaller AMT’s than that one, but yeah, they are still much larger than a dome.

Yes, having a low crossover point is great, but you can find that in a number of good tweets for a lot less. Maybe down to 1.8 kHz though.

It is a nice driver though, don’t get me wrong, but the relative value is a bit of a head scratcher. :) However, perhaps they are like SB Acoustics. The wholesale could be MUCH less than that, less than half. Then it becomes much more interesting. :)

Best,

E

BTW, top-end AMT tweets measure as well if not better, but are in the same price bracket too. 

@timlub 

580 EU / $680m US really IS pricey. 

On the other hand, with that output level it would go well in high end professional monitors mated with low compression /low distortion mids and woofers. 

Shame the reviewers did not compare frequency compression

seanheis1:

Magico's are also Be (with a graphite veneer). Same Scanspeak motor. 

The Focal's use a micro-motor which I normally dislike. B&W also uses a micro-motor tweet. They are designed to draw attention to themselves. 

Best,

E

seanheis1: 

Have you heard Be tweeters besides the Focals?

Best,

E

The plasma tweeter has some really interesting characteristics. I've heard it. Meh. 

I'd be happier with a top of the line AMT or Be from a number of vendors. This was at an audio show in a cramped room though, so it's quite likely I never heard it to full potential. 

@ejr1953 - Yes, well designed arrays are pretty impressive. They have some of the same advantages of large ESL's without their limitations. 

Yes, some use relatively inexpensive "full range" drivers, and adjust them using DSP to make floor to ceiling arrays and they are pretty impressive. 

Hi Realthing,

The article I know of from Pass was about using current sources + EQ circuits for certain types of woofers, in which he felt you would get a better response.

As far as I know, Pass has never attempted to sell all speakers as benefiting from this approach.

Best,

E

Feedback is good!

I am sorry if this is coming off as heavy handed. I have seen a number of good threads devolve into "my brand X is much better than your brand Y" or "you aren't getting 4D sound..."

So long as we can avoid that, all participation is welcome, especially from those with first hand experience, including and of course, especially @prof

I would like us to bend towards manufacturing choices and what kinds of pro's cons each has.

For instance, MBL's are pretty expensive, and seem to need lots of room. Just saying. :)

Best,



Erik

@prof
Maybe I missed it, but in your original posting there was nothing about the technology. I only saw subjective opinions.

Also, no reason why you can’t mention it in comparison, in fact I would like you to. :) Let’s talk materials, operating principles. How does the motor work? How does it measure? What about room tuning and placement?

Of course, it is also impossible to take a tweeter out of the context of an entire speaker. However, I really want us to discuss trade-offs, benefits, costs of the technology.

"Brand X makes the most realistic speakers I’ve ever heard" doesn’t enable that type of discussion, and there are plenty of those threads around.

Look forward to talking about how the MBL drivers work, and even how the tweet is different from their woofers, etc.


Best,

E

Gents,

I agree, it's impossible not to discuss brands entirely, especially when a technology is entirely proprietary like MBL seems to.

I would like to focus on the technology and trade-offs. The post by @prof reads identical to an MBL speaker review. I'm sure it is well intentioned, but I'd like to discourage them in this thread, other threads may of course be started by anyone.

As mentioned, here are my guiding principles:

Stay focused on tweeters and their manufacturers (when known)

Discuss the technology, materials, construction, and trade-offs

Discuss comparisons to other similar and dissimilar tweeters

We will sometimes have to mention specific speaker brands, it is inevitable, but if we make speaker reviews common in this thread it destroys its focus. I really want to avoid this thread becoming "Speakers with good tweeters"

Ultimately of course, this is a group effort, so the contributions are what make a good thread, I just hope we maintain the purpose and add in the spirit of discussing technology and value.

Best,

E

@prof


I’m glad you found a commercial speaker brand you like, but I need this thread to avoid devolving into brand flame wars. To avoid this in the future please:

• Stay focused on tweeters and their manufacturers (when known)
  
• Discuss the technology, materials, construction, and trade-offs
• Discuss comparisons to other similar and dissimilar tweeters
  

I really wanted to focus this thread on the tweeter drivers, their technology and trade offs. I really wanted to avoid discussing specific consumer speaker brands. I certainly did not mean to start a discussion about entire commercial speaker from top to bottom.

It would be interesting to know if anyone else has heard an omni tweeter they felt delivered outstanding dynamics and realism.

Best,

E

I have discovered something:

The very best tweeter to reproduce a Kazoo is an AMT.

That is all.


E

@wolf_garcia

Not saying tweeters aren't important, but their price and attention can be oversized to the rest of the speaker. :)

I have AMT's and ring radiators with solid center poles, and no friends, so I'm safe. :)

There are two Be tweeters I'm dying to try. The SB Acoustics which was recently released and the really low profile Be from ScanSpeak, especially as it may work in Focal's as a retro-grade.

But, neither time, money or energy are alignining right now.

Best,

E

And that expensive speaker, it's a real laboratory of measurements vs. experience. The off-axis sounds very good to me, but the overall tonal balance never did. I attributed the latter due to compression, but also really trying to stretch a small woofer beyond its capabilities. 

I won't go into it here, as it causes a lot of passion, but I encourage anyone who can to look at the specs and listen. It's interesting what does and does not correlate with experience.

@audiokinesis

Like a lot of tests, there is no way to exclude all other dimensions or confounds.

You are absolutely right in that these tests cannot be completely devoid of thermal issues.

And yes, price is no guarantor. Wharferdale Diamond's for instance have outstanding tweeters in regards to linearity, and many have expressed surprise at how good they sound after inexpensive cap upgrades. :)

Best,


E

Hi Duke,

I may be using the term incorrectly. Generally when I read about compression, it’s not thermal. This may be due to the fact that I don't read or do much with professional level gear, in which this is a major concern. Thermal compression can be seen with tone bursts, and you can see that after the first couple of cycles the output drops remarkably.

"Static" or common compression is measured by comparing the FR at 2 different input levels. Find your level for 70 dB at 1kHz. Measure the FR. Add 20 dB of input voltage. Measure FR. The output should be +20dB everywhere. Wherever the output is NOT +20 dB is evidence of compression.

Thermal compression is caused by heat, and therefore it’s effects are changing with previous input. What I’m calling "static" compression is related more to the limits of the driver’s linear travel.

Look at the "Deviation from linearity" charts. Here is a speaker with excellent "linearity" or lack of compression:

http://www.soundstagenetwork.com/measurements/speakers/paradigm_studio10_v5/

And here is one with relatively poor linearity:

http://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=1564:nrc-measu...

Best,


E

@audiokinesis

While this thread is focused on tweeters, we should realize they provide the least contributions to the music, measured by energy content. Lots of listeners could loose both of their tweeters and not realize it by hearing. :)

Also, compression comes in at two types, as far as I know.

Thermal compression means the driver heats up, and efficiency is lost. This can happen extremely quickly, within a couple of Hz. What makes this so nasty is that essentially your speaker plays differently after warming up than it did at the start.

Then there's static compression, which all drivers have, but some more audibly than others. This is a limit of the suspension and linearity due to the coil and magnetic field. The static compression is relatively easy to measure, and AFAIK Speakermeasurements.com is the only commercial speaker reviewer that does so. IMHO this is something Stereophile should have incorporated decades ago.

Thanks Tim!! I'm done with speaker building for a while. I made the speakers they'll bury me with, though I still keep tweaking the crossovers. :)

Best,

E

Hey Wolf,

A tweet that did not require a crossover would be quite an unusual find for me. Point me at a spec sheet?

Is this because of their inherent capacitance?

E

Hey Doug!

I think it depends on the ring radiator, but also the designer.

A lot of DIY designers cut their teeth on soft dome’s which naturally have a roll-off in the last octave. Switching to a ring with perfect extension past 20 kHz really can bite them in the butt, or the ear canal. :)

I’m using the Vifa/Peerless XT25BG (the dual magnet versions) and I have nothing but good things to say about their sound and measurement. However I have read some complain about it’s harshness, something I absolutely cannot find in the 3 I use.

Of course, like everything, Ring Radiators vary a lot! :) The XT25 comes in at least 3 different off-the-shelf versions (who knows about custom?) and I have not heard them all.  Versions been used in designs from Magico, Sonus Faber, YG, Krell, Polk. Harshness was not attributed to them.

I have listened to speakers with the top line ScanSpeak's with the needle-like phase plugs and never been overwhelmed.

Best,


E

Alkaloid,

Nothing wrong with that! I’ll take a silk-dome with a strong, modern motor over a lot of poorly implemented Be or AMT’s any day. :)

Their natural rolloff also helps with crossover design and prevents harshness.

Best,

E

Hi Sean!

For those who don’t know, the P7 preamp is unusual in an audiophile preamp for both having a pair of 5.1 channel inputs as well as pretty versatile bass management.

I think it’s a matter of the particular circuit choices in the P7, and not an issue of crossovers in general. It sounds dynamically compressed. To my ears, I don’t think Parasound took the same care in the bass management circuit as they did the rest of the pre. I felt that the sound coming out of my main speakers was just not nearly as transparent whenever the high pass filter was engaged.

This is NOT an issue i have with movies, but then all the bass management is being done digitally in the Oppo 103.

I probably could have tried running L and R full range, with the sub but meh... Instead I decided to optimize the Subwoofer, especially the EQ section, for movies, and it's fab.

Best,

E

bgpowell,

Cool, what do you think? :)

E

Here’s another example of how different similarly named or looking tech can be. Look at comment #9 regarding the design of the prototype ribbon from Hi-Vi RT-2 for the Carver Amazing loudspeaker:

http://www.diyaudio.com/forums/multi-way/300122-bob-carver-newest-als-system.html

I was thinking of something, for those who think I’m a super AMT fan, I’m not, but I have the most experience using them in designs. :)

The following is true for me:

Some of the worst sounding, and best sounding speakers I’ve ever heard used AMT tweeters. I ascribe this to the vastly different quality of the tweeters, and the effort needed in the crossover by the inferior tweeter to get it to integrate with the rest of the design.

So to me having an AMT tweeter is no mark of quality, and I think the same for other types of drivers. It's the final execution of the driver itself, and then the speaker and it's environment.

Best,

E

I don't mind talking driver brands... we're unlikely to get a ScanSpeak or Faital troll to show up and start harping on the quantum effects of their drivers.  :)  Plus it helps to talk about specifics in case we want to point to specifications. :)

So maybe we should say "No proprietary drivers" discussed? :) Then we can talk about a specific midrange, and talk about who might be using it. But yeah, really don't want a paragraph or 20 talking about how speaker brand X is so amazing it isn't even a speaker anymore.

Best,

E

Hey SoundsrealAudio, can we stay off ads for specific speaker brands in this thread please?

I really would like to focus on general design theory. As soon as brands get thrown in threads get really dirty.


Thanks,


E

I agree @timlub

I also only meant to criticize myself for going off topic, since I had originally only meant to talk about tweeters, but so long as we stay away from bashing specific manufacturers and stick to design principles I guess it's all good.

Sorry if that sounded like I was criticizing you at all.

Best,


E

My current "ideal" system is a 6.5" mid-woofer with subwoofer. This let’s me use significant DSP on the lower 2-3 octaves, but I truly only use it for movies.  I would use it all the time but engaging the crossover in the preamp I use (Parasound P7) really diminishes the sound. Not a problem during movies though.

I can’t imagine trying to get those lower octaves in an apartment without a sub and that EQ feature set.

Of course, I also use bass traps and panels from GIK Acoustics.

Best,

E

Well, we're far off topic now, but I believe the Snell A models used woofers with added mass to lower the resonant f and gain bass extension. A poured potting compound or something like that.

Also shortened the lifespan of the driver since the suspension wasn't built for it... but hey! That's what upgrades are for.

Hey @asvjerry

Usually when I hear about issues integrating woofers with very light tweeters it's a frequency response issue, and integration with the room issue.

Below 400 Hz especially, woofers are going to have issues the tweets will never have, so it's kind of an unfair comparison in my mind.

I can make a lot of reasonably good 15" sub's sound as "fast" as any ESL/planar/magnetic. But it's a giant PITA. :)

Best,


E

Please replace Roger Sander's "new" company, Sander's Sound where I typed InnerSound. Sorry Roger, I'm stuck in the past.

http://sanderssoundsystems.com/

Driver Quality

Lots of high tech labels may be ascribed to drivers. Such as:

• Beryllium
• Diamond
• Ceramic
• AMT
• Ribbon
• Ring Radiator
  

And that’s fine, but truth is that in all of these types of tweeters manufacturing quality varies a great deal. For instance, Accuton makes at least two different ceramic cone 6.5" midwoofers, with vastly different price points, both have a ceramic diaphragm. The prices for the same size AMT may be between $30 and $500 (from very diff. manufacturers), and yes, they are completely different. About the only thing they may share is dispersion, but frequency response, distortion and dynamic range are simply not the same.

One of my pet peeves is diamond or Be tweeters with micro drivers. Tiny motors barely larger than the diaphragm. They are never that smooth or have that much dynamic range.

Two of the most important measurements for me are Comulative Spectral Decay and compression. The first measures energy storage, or "blur" that a tweeter adds to the sound because it won’t stop fast enough. The second measures how a tweeter’s response changes at different volumes. Really outstanding drivers have very fast decay, and very little compression. Among the top-class Be/Ceramic/AMT/Ribbont tweets they all achieve this. Then there is everybody else! :)

Dispersion -

This measures how wide or how tall a driver’s output is vs. frequency response. Like many other factors, there is no 1 best type of dispersion.

The wider a driver’s output, the wider the "sweet spot" or where a listener may be and still hear a credible stereo image. However!

First, for any given type of dispersion, speakers need to roll off more or less evenly. You don’t want to be 15 degrees off axis and only hear the mid-range. Ideally the speaker’s dispersion is even across as much of the response as possible, but usually this can only be done starting in the upper bass.

Next, the wider the dispersion, the more early reflections you may encounter, which can severely affect the frequency response and imaging. Acousticians designing a theater or monitoring room trade off dispersion vs. room treatment. A very tightly controlled speaker needs less room treatment and care.

A number of things affect dispersion, including the obvious things like wave guides (YG Acoustics, Revel’s F series, Krell, first gen. Magico) or horns, diaphragm size (larger = narrow) and crossover points.

The very large diaphragms of ESL speakers (Martin Logan/InnerSound, etc.) have fabulous clarity thanks to this effect. They can sound like you have headphones on even with very little room treatment.

Drivers with different dispersion patterns _may_ also have different rate of decay. Consider a hybrid ESL + cone woofer. The woofer radiates omni-directionally and the wavefront looses energy the fastest, while the ESL panel is a plane wave, with narrow dispersion and looses energy more slowly.

This means that changes in distance from the speaker causes the woofer to loose dB faster than the ESL panel. This has a very simple solution however: Put a volume control on the woofer.

With smaller drivers, like say 5" tall ribbons or AMT’s this difference may be too small to worry about and can be handled strictly in the crossover, though a volume control switch may also be used if absolutely required.