opinions on the new VIFA dual conc. tweeter XT25

[bbaker6212]

FS: XT25 pair

I have a pair of XT25's I'm not using.
If anyone's interested make me an offer.
They were used only for a couple days...
when I stupidly replaced my D2905-9500's in
my Ariels "just to see how they sounded".
Of course they didn't sound better than the
9500's since the crossover was tuned
for that tweeter - Duh!

Guaranteed not abused and working great..
not even broken in yet!

-Brad-

 

[JonMarsh]

Zobel for the XT25

RC network for inductive rise is 2uF in series with 14 ohms; FS zobel is (expensive!) 130 uF + 0.7 mH + 4 ohms all in series.


-Jon

 

[jteef]

Does anybody know the basis of the design of this speaker? Just from the looks of the pictures it is very similar to a loudspeaker design I have in my acoustics notes. The goal of the design in my notes is to greatly reduce/eliminate the resonant modes of vibration in the cone, both concentric and radial(also referred to as Bell modes) through the use of different materials and cone structures to properly terminate the cone, surrounds, etc and interrupt the standing waves on the cone. I think my old acoustics professor(Dr. Eugene Patronis) had a hand in the design process along with another fellow by the name of Krüger(dont remember his first name)

My professor demonstrated a pair of 3.5" "full range" (70hz-13khz i believe) speakers based on their research during class one day and they did indeed sound very nice and had excellent polar response/dispersion. He said the reason they never made more than a half dozen pairs is the expense involved as the entire thing was hand made and wouldn't lend itself to a machine process very easily. (I believe one of the materials in the cone was a layer of womens panty hoes...) The "mechanical impedances" of the materials and their respective connections were an integral part of the design.

So, if anybody knows if these two might be related or could give me some more background into the design of these particular drivers, i'd be grateful.

jt

 

[Tom Brennan]

Things look like JBL "Ring Radiator" horn tweeters without the phasing-plug and horn. These JBLs use an aluminum ring as a diaphragm, come with several horns and phase-plugs; bullet, slot, catseye and buttcheek. The original JBL 075 bullet goes back to the 1950s. Doesn't look like Vifa and Scan-Speak are onto anything fundamentally new.

 

[jteef]

an email conversation with my old professor indicated that the d-s-t speakers were not designed from the same concepts and that his design remains unique. oh well...

jt

 

[bostarob]

I like the 5 mounting holes. 5!

I think I may try it out, it isn't prohibitavly expensive.
Tweeters w/out ferrofluid are said to sound better than their mechanically damped counterparts. How different?
-andy