Tweeter Types

What are the advantages and disadvantages of the various types of tweeter?

Thinking quickly there are the following types:

Soft dome.

Metal dome.

Horn.

Tweeter part of dual concentric driver.

Ribbon.

Electrostatic.

Piezoelectric.

 

compression.

 

Are you suggesting some tweeters compress the dynamic range?

Then how do you rank them?

 

Brian Hi ,no I was thinking of compresion tweeters like the TAD703
Keith.

 

Ah.

I found this wiki

http://en.wikipedia.org/wiki/Tweeter

I had remembered the Ionofane from when I was aboy, but didn't list it.





Is the compression tweeter just a horn variant?

 

This is the 703, horn loaded compression driver, the best tweeter made.
http://www.pioneer.co.uk/eur/products/45/200/1083/ET-703/index.html

 

The tweeter part of the DualConcentric is a horn loaded compression driver.
Comp drivers make the best HF imo. The TAD is matched by the JBL 045be imo.

 

A few very general points on some tweeter types:

I think that good metal domes probably give best bang for buck.
There have been some nasties around but they can be extremely good. They suffer two main problems - sharp resonant peaks at both ends of the range, however good ones will push these well outside of the passband leaving what remains as very clean and low distortion. Good metals are usually pistonic right up to 20khz and truly exotic types such as beryllium go far higher.

Soft domes seem to vary hugely in performance and many seem quite poor. Break-up is often evident and this is sometimes tamed by doping, which helps mask the problem but really just swaps one problem for another. They lack the sudden and nasty peaks seen at the extremes of the range with metals.

Ribbons can be great but usually need a matching transformer if the amplifier isn't designed to drive a near short - not many are!
Low moving mass, usually great lateral dispersion and poor in the vertical plane. The low impedance means that a lot of current can be passing through the delicate ribbon element and therefore many ribbons are fragile, older designs especially are prone to burn-out. Don't work well at the lower end of the treble range, which is why you often see a presence suck-out when ribbons are married to a cone mid/bass driver.

Isoplanar types are really a cross between the moving coil and the ribbon in many ways, with the coil stretched out onto a flat plastic 'ribbon'. Many of the advantages of true ribbons but easier to drive and more robust.

Electrostatic has very low moving mass and the moving element is driven push-pull evenly over the entire surface. This gives very low distortion. Getting decent power handing and with enough range to extend down to match a mid unit makes them quite large, so the same lateral/vertical issues often apply as with ribbons.
Hard stop power handling - overdrive is sudden and destructive as arcing occurs suddenly between the electrodes. The result is a repair bill.

 

The other tweeter that has always impressed me is the 'corona' ION used by Lansche, their speakers have always impressed me.
Keith.

 

One can class tweeters by motor principle, i.e.

voice coil
electrostatic
planar magnetic
ion
ribbon
piezo

or by membrane type, i.e.

cone
dome
planar


or by coupling

direct-coupled
horn

or by membrane material

metal
cloth
foil
ribbon
paper


Lots of possible permutations.

 

And then theres the plasma tweeter,biggest problem is they can take out your neighbors telly

 

I came across this on dome tweeter materials

http://forum.ecoustics.com/bbs/messages/34579/592024.html

I have listened to titanium tweeters for 20 years, and like them immensely.

http://forum.ecoustics.com/bbs/messages/34579/592024.html

 

Didn't the plasma tweeter get withdrawn due to the risk of killing the listeners?

 

Small price to pay for ultimate sq!

 

A tweeter dome moving back and forth a few millimeters? Yeah, right.

 

my fave tweeter ever was the linaeum tweeter so clever and beautiful sounding.

self horn loading, di pole ,extremely light weight and very cheap to make.
shame they never really took off.
i love em'

 

I can remember seeing plasma tweeters demoed on Tomorrow's World around 1980. They look like fun, but even if they could be made electrically safe, I'd worry about all that ozone.



I think it's hard to make a call on the 'best'. Surely it's at least as important how well integrated they are with the other driver(s)? Electrostats can sound fabulous but often need a little help at the very top. I'm a big fan of the compression horn in the Tannoy DC but I'm sure that's as much to do with how Tannoy implement it (alignment, crossover etc).

 

Compression definately. I wonder why on earth "hi-end" firms do not use them more often. The difference is so obvious. Any reasons apart from the price?

 

An easy question for me.

The best tweeter I know is the TAD ET703. That is in the £1,000 + category.
Sub £1k for a pair, JBL 2405 is my favourite tweeter.