Horn loaded ribbon tweeter

[Waldek]

Hi,
Yes those are kelly ribbons.. and probably sound very good as well.
A kelly ribbon is fairly simple.. The only question is how good is the horn design. Designing a horn to it is more difficult..
But it seems they copied the original so... should be OK.

I have a pair of Decca London ribbons my self and now thinking out a design for a complete loudspeaker...
Problem with these great sounding units is to couple them with an midtone unit .. we have seen a lot of designs were a cone midtone is used .. but the problem is obvious the midtone has to much spreading in comparison to the hi tone horn. So im looking for a mid tone horn design to go along with it, it would be nice if the midtones could come from a single horn starting from 300Hz or so.

Greetings, Walli

[medum]

Originally posted by cocolino

........Due to the VERY poor build qualtity I would NOT recommend buying this tweeter when it is still built the same way as it was in former times (what I assume)........

Well, I owned a pair of Gamma Ribbons back in the late 70's and I combined them with the famous Jordan-Watts full-range speakers.
I was very satisfied by the sound then, but the speakers were quite fragile, and the ribbons blew up easy, if your amp didn't have a delay relay circuit.
But you could easy repair by using the thin aluminium-foil from a foil capacitor.
I don't agree with cocolino in his judgement of the Gammas. Sound was great at that time. How it is nowadays - I can't tell, of course. I was surprised to see, that this bulgarian tweeter still exsisted.

[Sjef]

I have written some times about thes so called Gamma horns in other topics but o.k. again.

I own two pairs of these, bought in a shop in baulgaria for about $25,- per pair at that time (1991) They are exactly the same as the Expolinear ribbons wich are sold for a lot more money in Germany. In fact the Expolineair HRL81/82 comes from the very same factory and has the same build quality, I know because I have had them both (also for $25,- a pair, while the expo's had cost me $300,- a pair, yes for the very very same product)

I don't agree on the poor build quality. The materials used look a bit rough (especialy the paint) but everything is actually of the same quality as a lot of modern drivers I have had, they only looked better. A Raven or Aurum cantus has the same rough quality if you take the cover off. Ever looked inside of a ESS air motion transformer ? I own a pair of them too but these are of a much poorer build quality.

I also don't agree with the problems of the diaphragms. Off course there are some problems but these are the same as with every aluminium ribbon tweeter I have seen (even the most expensive ones) It's a tricky job replacing the diaphragms and you need to clean the contacts indeed. Replaced the diaphragm twice because the magnet atracts little pieces of metal very well. Never destroyed one with playing music.

I have owned a pair of Decca/Kelley DK30 ribbon horns but I have changed them for a couple of Focal dome tweeters at that time (according to everyone some of the best tweeters at that time) still regret this action.

I have compared the Jordanow/Expolniair/Gamma horn to the original DK30, measured them in every direction and I can tell you the horn shape is excactly the same, it is a copy of the DK30. I have compared them in sound quality and found the Jordanow even slightly better sounding than the DK30. the Jordanow has a higher sensitivity, an other type of transformer and uses a aluminium/plastic foil ribbon while the DK30 foil is of pure aluminium. The foil looks indeed like the foil of a rolled metalized mylar/polypropyleen capacitor.

The real problem with this tweeter is that the horn is rather deep so you will get an offset between mid and high wich is simply too big. Its very hard to make a good combination that way. Digital crossovers with adjustable delay helps a lot here (from my own experience)

The problem with the directivity is another one. It's hard to combine i with a small midrange driver because the difference in directivity is too big at the crossover point. It goes very well with an 8" driver at say 3,5kHz. the directivity of both units is about the same at that frequency so integration is even better than with most non directive tweeters then. But there lies another problem. Where to find a 8" driver wich is fast enough to come up with the tweeter ?? Almost 90% of the 8" drivers fall short on this. Another thing is that they like really steep crossovers. If you go passive try 36dB/oct, they really like that, forget about 6 or 12 db filtering.

Anyways, believe me or not, I think if you handle the tweeter propably it's the best bargain I have ever came across in my life. If you ever visit Bulgaria, go and buy them all while you can. (I'm afraid Expolineair and ATD have bought them all)

[zobsky]

Originally posted by Mikael Abdellah

I'm planning to build a 2-way spekaer with this and a Fostex FE166E. Would that make a nice speaker for my low-power tube-amp???

i don't think a fostex fe166e absolutely needs a helper tweeter, unless you are cutting off the high frequencies, .. maybe the 206e , but definately not the smaller 6.5 inch drivers)

[Leeuwarden]

Expolinear is absurd expensive. If you are looking for ribbons/planar speakers try www.partsexpress.com

[Sjef]

and so is ATD.

[icefox]

Hi guys,

I've recently acquired this pair of speakers would like to get some advice on the application of it.

Please see Gamma Horn loaded Ribbon VLD-13 - Application Advice Needed for more details.

iCefoX

[mhelin]

Originally posted by Sjef
The problem with the directivity is another one. It's hard to combine i with a small midrange driver because the difference in directivity is too big at the crossover point. It goes very well with an 8" driver at say 3,5kHz. the directivity of both units is about the same at that frequency so integration is even better than with most non directive tweeters then. But there lies another problem. Where to find a 8" driver wich is fast enough to come up with the tweeter ??

Seas 21RFX/P

Btw. Do you have to go to Bulgaria to get those tweeters.

[Hjalmar]

Hello,

you can order the Gamma VLD-13 from Hifikit in Sweden HIFI KIT ELECTRONIC AB - Högtalarelement HiFi Hembio Billjud/Marin Studio PA/DJ Kablage Tillbehör or try directly with the factory Vissokogovoriteli PLC, Blagoevgrad, Bulgaria

Sjef is right regarding integration with woofers.
I once built a surprisingly very nice sounding transmission-line speaker with a Beyma B-80B and a the VLD-40. I filtered 18dB at around 3.5 KHz.

The version without horn goes from about 5kHz up and the VLD-80 from around 3.5 kHz

Regards,

Hjalmar