Fertin 20EX measurements?

[RyanC]

Hello-

I am interestd in the fertin drivers, people seem to have great things to say, but I would like to see some freq plots, especially off axis. Or if anyone has them can you tell me where they get beamy? I would love to know where -6dB is at 30 and 60 degrees. . .

I'm stuck in a debate between somthing like the fertins or the ATC soft dome mid. These are for studio monitors (3rd revision now) and even off axis response is VERY important in the studio. Ideally I would lke to have a very wide range driver with tweets and woofs to cover the extremes. Also the fertins look promising as accurate dynamics are very important to me. Thanks for any input you all may have. . .

 

[ScottG]

finding anything on feritin (besides their website), is extremely difficult.

virtually all 7 inch drivers start deviating from their on-axis response between 1 kHz and 2 kHz (typically 1.6 kHz). Even drivers with whizzer cones have this problem - but they usually have better performance an octave above this area for at most two octaves. Worse ALL whizer drivers create a resonance between whizzer and cone. So in my opinion.. IF you want a flat on-axis and off-axis response and you are not willing to have a tweeter crossed low (around the 1.6 kHz), or have tweeter crossed up a bit higher but with a low order crossover, then you'll need to look elsewhere (and possibly the ATC mid).

Now there is an alternative.. you could horn load a feritin which has a rising response on axis. This would limit your ultimate off-axis response, but with a good design you could end up with a fairly flat response in at least a 60 degree "window" (i.e. +/- 30 degrees). This is what people are doing with the BD-designs ORIS horns. Who knows, you might even find a feritin user there on their forum. Note though that you would still have the whizzer resonance problem. To counter this you could instead use a driver like the supravox 215-2000 EXC (which is reputed to be better than feritin's similar field coil), OR for a lot less money consider the Visaton B200.

 

[lrntglls]

Fertin off axes response

I'll e-mail Fertin and ask for a freqency plot(off axis) and I'll get back to you with this. If you ever want other info about their products , just ask and I'll do whatever to assist you. They ask me to sell their products Canada and the Us, so people would get a better response.

 

[Salas]

Here is an on axis one if of any use

 

[Scottmoose]

Ouch. That's one major jump up at 8Khz. The rest doesn't look too bad though I suppose -bit like the FE206E, or perhaps the ESigma in that it doesn't go quite as high. Good Xmax too. To be honest though, I'm becoming less and less convinced by the quality of 8" drivers like the 206/7 above, say, 15Khz. Luckily there isn't much musical information up there, it's more harmonics, but I'm starting to think rolling them off and bringing in a decent tweeter / super-tweeter around 10Khz is the way forward so they are running more wide than full-range. Call me a heretic if you will. The 6 1/2" drivers like the 166/7 are sweeter up top, and judging from its published response curve, and the couple of days I had a pair to play with in my enlarged BIB boxes, the 166ES-R is better still.

Cheers
Scott

 

[lrntglls]

Fertin off axes measurements

Salas, the picture that you have posted is the 20s not the 20EXC which has the electromagnetic motor. Also at 330 euros , it probably have the copper wiring , not silver. They sell for 323euros in Canada and the US. As for the wizzer cone, you have a choice of aluminum, brass and bronze. Today, I'll post some pictures and on-axes graph of the 20exc(copper and silver wirint) and of the 38EXC. I'm still waiting for the off-axes frequency graph.

 

[soulsheiksan]

in horns

a while back i tried a fertin ,feild coil in tqwt, open baffle and the oris horn, compared with the fostex 208e,lowther pm6a,
tqwt had amazing bass and was surprised at 40 hz compared with other 8 inchers, on open baffle they are very neutral, but to get them to sound right they ended up being 2 m by 1 m with pianio hinges for wings that were 0.5 m that was good but too big and room depedent, in the oris 150 i had to remove the back chamber for it to work,, great driver with lost of possibilities but found them too dark, did not try it with a tweeter though
best bet is open baffle ,tqwt

 

[zygibajt]

To be honest though, I'm becoming less and less convinced by the quality of 8" drivers like the 206/7 above, say, 15Khz. Luckily there isn't much musical information up there, it's more harmonics, but I'm starting to think rolling them off and bringing in a decent tweeter / super-tweeter around 10Khz is the way forward so they are running more wide than full-range. Call me a heretic if you will. The 6 1/2" drivers like the 166/7 are sweeter up top, and judging from its published response curve, and the couple of days I had a pair to play with in my enlarged BIB boxes, the 166ES-R is better still.

100% correct. There isn't much musical information but the overall performance benefits a lot. People say fullrangers sound natural, but their highs are week=unnatural, so the whole presentation is not natural becouse the highs are not natural. Same with bass

I've just bought AC G2se ribbons for my 206E and they really do a good job. When you match the tweeter very well with full range driver, the speaker seems to be a little less exited than without the tweeter, but I think it's just that it is more flat and extended. Full range driver sounds exited becouse it's not flat.