The merits of the various tweeter types

buggsson

Member
2005-09-10 7:38 am
I would like to know more about the differences between the various tweeter types out there, and their influence on the sound, as there are quite a few of them, such as for example:

dome (metal etc)
inverted dome
compression
ribbon tweeters

I've heard a few opinions about different tweeter types, but I would like to see a more structured comparison.
 
Should be something here
http://ldsg.snippets.org/

Just a few things to note

The compression driver requires the horn to be designed for it - see jblpro.com tech library notes.Ie dont just buy a random Comp driver and a random horn,you could get discontinuities.

As for dome vs non dome tweeters personally I think thats a less important discussion.

http://www.xlrtechs.com/dbkeele.com/papers.htm
15. "Improvements in Monitor Loudspeaker Systems," J. Audio Eng. Soc., (June 1983).horn + 15"

http://www.audioheritage.org/vbulletin/showthread.php?t=12126
Diy oblate spheroid in solid oak.this guy has a good technical idea of what hes doing and why.
 

buggsson

Member
2005-09-10 7:38 am
If I understood Zaph correctly, he was not very impressed with ribbon tweeters. I've been told that with a ribbon you would be able to cross quite low, but he did not recommend crossing below 2500 Hz with the ribbons under test. I wonder if these results are general for most ribbons, as my plans is to cross rather low?
 
Actually ribbons for the most part cannot be crossed as low as many high quality domes - good domes can be crossed well below 2500 Hz. 2500 may be low for a ribbon, but I've seen domes crossed as low as 1400 Hz (with very carefully designed crossovers).

So "low" is a relative term I suppose, but if you want to cross below the 2k - 2.5k range you may want to consider domes.
 

buggsson

Member
2005-09-10 7:38 am
auplater
Have you had experiences with planars that have really good distortion properties below 2000 Hz? I think that was what Zaphs main objection were, high distortion at "lower" frequencies"?

Whas is the general opinion about manufacturers recommended crossing over frequencies, are they usually good, or at least close?
 
The lone distortion measurement is just part of the picture. I'd look at THD, its spectrum and how it scales with power.

The other part of the picture that raw driver testing doesn't show you is how it works with the actual network for the application. I think a lot of people are passing up perfectly usable drivers because one curve looks better than the other. Its only the final finished loudspeaker response that really matters and how the finished design scales with output. You won't know that until you build some designs and do the distortion measurements in the final system at various power levels.
 
second kevins comments on this matter. There is no perfect tweeter and also no single value which gives us a clue wether the tweeter is good or not. All kinds of things have to be factored in. THD, freq response, power handling... it is all accumulating to form an overall big picture. Depending on your design it can even be the size of the faceplate that has to match the look of the other drivers and whatnot.

There is no such thing as a single master measurement or value by which you can judge drivers.

Also ones experience with a certain driver can be worth mentioning. If you built several deisgns with the XYZ then it might be a good idea to call upon that experience since it will definetly make things a lot easier.

If i had to put it in a nutshell:

freq response
thd+ spectrum
power handling also including similar efficiency when compared to the other drivers of the speaker

Also id like to mention that i, too, do not believe in the idea of slow and fast tweeters. Althouh some tend to use this term a lot there is no such thing as a slow or fast tweeter. The speed of sound is always the same :) A tweeter in itself is never slow. Combined with your xover you might be able to see differences in rising time/ impusle response and whatnot when measuring the speaker.

Usually thewoofers will have like 25 to 35 ms delay and stuff. If you have an active speaker you can easily play a bit with it. Why not try building a closed baffle woofer which has pretty good and fast response as we tend to say.. and then simply use the dsp xover to set delay to 20ms making the fast cb woofer slow intentionally. You will find out that what is often described as fast bass is not really the delay but instead its simply the fact that cb sounds differently than br designs...

just my 2 cents
 

buggsson

Member
2005-09-10 7:38 am
There is no such thing as a single master measurement or value by which you can judge drivers.

I know that much, but that is about all:D

Seriously, I just wanted to try to find out if there is anything to go by when trying to select the tweeter, you cannot just simulate them all and hope it will work in the end. I was hoping there would be some guideline/s to follow, now at least, I find that I have something to go by.
 

jagster

Member
2008-02-27 6:06 pm
More on Tweeters, as if we need to add more!!!!

Tweeters are all over the map, and lots of people have tried to guild this lilly with their opinions. I have been around the hi-fi game for lots of years, and have heard most all the technologies. Yes, I owned Quads with tube amps to power them, and they are outstanding mid-range speakers. I have had Infinitis with EMIT tweeters, and have fried a few in my time. Kind of edgy to my ears. The old PHillips domes are hard to beat for smoothness, same for ADS. The silk domes in the high-end Marantz speakers out of the 70's may not impress anyone, but they are smooth. I have Klipsch Heresy's and they are very decent and do not tire you out like some folks say. Also, if you know any people that play or enjoy piano, ask them about the Klipsch's. I have Polk SDA-l's and have yet to plug them in ( shame on me), but have been told they are outstanding, but are 'tubby in the bass'. And yes, I have 'rolled my own' speakers,and have not had too much success, even though they sounded great to my ears. I put them up against my prize speakers, and they are systematically blown away, so speaker design is part art and part science. Either buy something that many knowledgeable people like, or just pick up a cheap equalizer and play until you find your 'sweet' spot. All ears were not created equal, and if you start with that premise, I don't think you can go wrong.:smash:
 

jagster

Member
2008-02-27 6:06 pm
Introductions

Gosh, I ;just tried post a brilliant introduction,and it told me to pic a forum, and then lost the whole thing. A half-hour, just gone into the ether. If you want folks to introduce themselves, there needs to be an easy way, just a suggestion. Probably my fault, as I am not a PC guru.
 

Dr_EM

Member
2006-10-18 12:00 pm
Swindon
I definately prefer the sound of my Hi-Vi RT2EA planars to the metal dome in my B&W DM602. They have a much crisper sound with high range synth sounds and cymbales are more real sounding. Vocal sibilance is more airy and less forward/exaggerated. Imaging is excellent overall, I think the tweeter plays a fairly large part in this. They are crossed high at 4.2khz though, I have mids that will easily take this to match. Far too limited an overall experience with either technology to say one is better though, the Hi-Vi tweeters part cost is probably many times higher than the B&W tweeters anyhow.
 
buggsson said:
What do you use? I've tried to find mids suitable to cross above 4000 Hz, but so far they are very few, if any.
Many Tang Band (wideband and full ranger) meet that description. See Harbeth Monitor 40 as an example layout, although there's opportunity to scale it to smaller sizes.

What I wish that someone could answer is the question of dispersion discrepency between tweeter and lower frequency drivers, when used in non-studio rooms (ordinary homes). Here is where the dome tweeters tend to spray treble about, and it isn't accompanied by the rest of the spectrum because lower frequency drivers have smaller dispersion. So, a frequent compensation is extra hot midrange for on-beam locations. Personally, this is insufficient fidelity.
How to fix?
Thanks!