Which type of tweeter is the best, and why are there so many types of them?

[Pearljam5000]

There are many tweeter types and technologies :
Cone tweeter.
Dome tweeter.
Piezo tweeter.
Ribbon tweeter.
Planar-magnetic tweeter.
Electrostatic tweeter.
AMT tweeter.
Horn tweeters etc.
On the other hand bass drivers are basically mostly the same.
Which type of tweeter is the best and why are there so many types of them if they all achieve the same goal?

 

[Jdunk54nl]

They all don’t achieve the same goals. If you are referring to just frequency response goals, they don’t even all achieve that same goal. Some can play lower frequencies compared to others. Others have different directivities,
With tweeters, you have to really account for directivity/beaming issues and how low it can be crossed in your design. Other drivers, you can design them to play mostly omnidirectional within their band pass.

 

[Jdunk54nl]

This is a simplistic chart, but gets to the point above
Even a 1” tweeter starts beaming around 10,000hz. Ideally you would want all speakers in the green and maybe slightly in the yellow, but red would be very narrow directivity, sometimes that may be your goal though…

 

[DVDdoug]

Which type of tweeter is the best and why are there so many types of them if they all achieve the same goal?

Different goals and trade-offs and often different marketing goals.

There are lots of ways to build a speaker and the manufacturer always touts their choice as a desirable feature. The same goes with materials... "Mylar dome" or "soft dome" or whatever they use will be touted as "the best", or sometimes the more expensive choices are touted as the best.

It's best to look at specs/performance rather than the design/construction.

A regular dynamic speaker with a coil and magnet (cone or dome) is usually the most efficient (higher SPL output at a given wattage). Add a horn and you can get more loudness/efficiency (with more directivity challenges, I think). Most PA speakers use horns. Most of the other designs are less efficient.

Piezos can be efficient and have high "power" handling. Actually they have higher impedance, and they are capacitive so it's more accurate to say they can can handle higher voltage. But just from listening (not measuring) they tend to be resonant (non-flat frequency response). I have piezo tweeters in my van because I fried my regular (dome) tweeters.

On the other hand bass drivers are basically mostly the same./

With woofers there are still lots of material choices and various enclosure choices.

 

[Wes]

bamboo tweeters just sound more organic to me than the beryllium tweeters

 

[Pearljam5000]

bamboo tweeters just sound more organic to me than the beryllium tweeters

I still think beryllium has a unique sound.

 

[King_Pin]

Best as in sound or measurements?
I would think that different people prefer different types of tweeters.

 

[Kvalsvoll]

There are many tweeter types and technologies :
Cone tweeter.
Dome tweeter.
Piezo tweeter.
Ribbon tweeter.
Planar-magnetic tweeter.
Electrostatic tweeter.
AMT tweeter.
Horn tweeters etc.
On the other hand bass drivers are basically mostly the same.
Which type of tweeter is the best and why are there so many types of them if they all achieve the same goal?

Having worked with tweeters of all but the electrostatic, I should say the tweeters I use now are the best - and they are. But not necessarily due to principle - because it is all in the execution, as always.

Some of the worst may be attributed to technology in use. I remember those piezo horns, the were quite bad. And there is a reason why small ribbons are not as popular as they once were - there are physical limitations present.

 

[q3cpma]

To be simple: metal dome tweeters because they stay pistonic in the audible band, have a relatively uniform wavefront that can easily be shaped by waveguides (incl. widened at the top end) and stay relatively inexpensive for aluminium and titanium stuff. Compression drivers too (which I personally define as producing a flat wavefront), but they're generally about greater SPL and use bigger size that means unavoidable beaming and roll-off at some point; I doubt they're needed in most Hi-Fi applications; even though they do great in GGNTKT and Genelec's stuff.
In general, this kind of question can be answered by deduction: what kind do the most performance and no-nonsense oriented companies use?

To be honest, I find the waveguide/horn/baffle execution much more exciting than tweeters themselves, which I'd call a mostly "solved" problem.

 

[dfuller]

Cone tweeter.

Probably the worst of the bunch, unless you'd include inverted domes here. There's a reason these aren't common.

Dome tweeter.

The most common for a reason, they work well in most respects and are "mostly solved". Whether soft or hard depends on usage characteristics but I find this matters less than you'd think as both can produce good results (though a cheap soft dome is sure as hell better than a cheap hard dome!). Also in this category (sort of) are ring radiators, which are very narrow beamwidth but can extend extremely high (the cheap Vifa XT25SC90 comfortably goes up to the 40khz region) though I hear if you place it in a proper waveguide the narrow dispersion problems are largely dealt with.

Piezo tweeter.

Can't say I've ever seen one of these used in a high fidelity situation.

Ribbon tweeter.

Great horizontal behavior, crap vertical; also they need a coupling transformer in line to have any appreciable impedance. Also insanely fragile as they're generally ~1-3 micron aluminum foil.

Planar-magnetic tweeter.

More or less a ribbon that does not need a transformer (nor is as fragile). Alternatively, an AMT that doesn't have the folds and therefore behaves like a ribbon.

AMT tweeter.

Unique technology, it behaves like a bellows. Seemingly hard to implement in a way that doesn't suck somehow though and quality below the very good ones is quite variable. In a mixing context they almost always sound pretty odd to me, not entirely sure as to why that is but that's been my experience.

In general, this kind of question can be answered by deduction: what kind do the most performance and no-nonsense oriented companies use?

The answer here, I would say, is almost any of the common types (i.e. soft dome, hard dome, AMT). I've seen all 3 get great results and poor results.

 

[Wes]

a 6 ft. tall ribbon tweeter is a good thing

 

[Kvalsvoll]

a 6 ft. tall ribbon tweeter is a good thing

A very good thing. The large size of the diaphragm solves the capacity/distortion problems, narrow so it was born with excellent horizontal pattern, so tall you will sit in the nearfield even at normal listening distance so the problem with very narrow vertical directivity is solved.

I used such tall ribbons on a planar magnestatic speaker I built in the late 80-ies, this was when the Apogees were the hot thing to have. While the bass panels had issues that made this speaker good for baroque and useless for everything else, the ribbons were pretty much solid both in performance and reliability.

 

[Helicopter]

I have some piezo horns here. I should make some 2 ways with them for giggles.

Beryllium domes are probably the best.

 

[MarcT]

This is a simplistic chart, but gets to the point above
Even a 1” tweeter starts beaming around 10,000hz. Ideally you would want all speakers in the green and maybe slightly in the yellow, but red would be very narrow directivity, sometimes that may be your goal though…
View attachment 139326

Interesting chart. Question: in which of those five graphs would tweeters from popular brands such as Focal, Revel, or KEF fall? For example, I've read that KEF is narrower dispersion than the others; would its tweeter fall more into the yellow or orange column?

 

[BenB]

Great horizontal behavior, crap vertical; also they need a coupling transformer in line to have any appreciable impedance. Also insanely fragile as they're generally ~1-3 micron aluminum foil.

You see narrow vertical dispersion as "crap" rather than a design choice? We aren't all so narrow-minded.

 

[thewas]

Which tyre is the best, a Pirelli P Zero 285/35R19 a Nokian winter tyre or a truck tyre?
Best tweeter is the one that in each case fulfils the needed requirements in the design of a loudspeaker in terms of frequency response, directivity, max SPL and distortions which can be very different for example on a hifi loudspeaker to a PA loudspeaker.

Also we shouldn't forget that if distortions are low enough and we leave out the different directivity of different tweeter types and EQ them to the same frequency response, they sound the same as shown in this work.

 

[mhardy6647]

bamboo tweeters just sound more organic to me than the beryllium tweeters

Well, I mean, beryllium is, you know, technically, inorganic.

 

[Trif]

To be polite, tweeters have a lot of problems. There are so many types because each type solves a problem, or two.

Everybody's hearing is different in the high end, mostly uneven. So we each have different tolerances for those pre-existent problems.

And we haven't even touched on "Titanium is better for cymbals and silk is better for strings". Which, unfortunately, can be true, sometimes.

So, uhm, there are so many tweeter designs because they're all lacking something. It's like lipsticks... in 50 years, they've never made the right shade....

 

[Wes]

Well, I mean, beryllium is, you know, technically, inorganic.

glad you got the joke

 

[Wes]

To be polite, tweeters have a lot of problems. There are so many types because each type solves a problem, or two.

Everybody's hearing is different in the high end, mostly uneven. So we each have different tolerances for those pre-existent problems.

And we haven't even touched on "Titanium is better for cymbals and silk is better for strings". Which, unfortunately, can be true, sometimes.

So, uhm, there are so many tweeter designs because they're all lacking something. It's like lipsticks... in 50 years, they've never made the right shade....

yes, a lot

to borrow a phrase from another science - the problems are "an N-dimensional hyper-volume" which the designer attempts to navigate