Fertin project - calling all open baffle experts

[bcherry]

Originally posted by dice45

caveat:
the Fertins are not meant and not suitable to work in a backloaded horn (if you mean the Lowther TP1). The driver is not completely airtight from diaphragm frontside to backside (which is a must for a horndriver). It will whistle thru the air gap!

[/B]

Brad,
Refers to this. There seems to be some differences of opinion over the suitability of the Fertin for a back-loaded horn. anyone know more about this?

Brian

[bbaker6212]

What air gap? Where's the air gap referred to? Are there holes in the cone, perhaps near the VC? This sounds strange to me.

[dice45]

Brian and Brad,


any voice coil needs an air gap to be able to move.

As the Fertin has a phase plug where some other speakers have a dustcap with is air-proof. The Lowther too has a phase plug but
1st
it has a way smaqller airgap than the Fertin
2nd
the innner suspension, the centering spider of the lowther is air-proof

The Fertin is not air-proof diaphragm-front-to-back with the basket sealed into the baffle. So on bigger excursions, it whistles thru the VC airgap.
Warning by the German dealer.

[bbaker6212]

I could see this being a potential problem with sealed or bass reflex cabs. Seems like a TL cab, in addition to the open baffle, would not have much of a problem with this.

[bbaker6212]

Btw, how's the imaging/soundstage with the Fertin given it's integrated whizzer cone?

Any forwardness/brightness like some report about the Lowthers and others with whizzers?

[bcherry]

This came up in one of out local HK boards.



http://www.audioboard.com.hk/abforum...osts/3728.html

It also presents some interesting alternatives for open baffle possibilities.

Brian

[bcherry]

Originally posted by bbaker6212
Btw, how's the imaging/soundstage with the Fertin given it's integrated whizzer cone?

Any forwardness/brightness like some report about the Lowthers and others with whizzers?

No 'shout'.
Just smooth seamless sound. Loads of detail/imaging from any position without aggressiveness.

Brian

[mgreene]

In regard to the potentially obtrusive baffle size that seems most appropriate for the Fertins, it occurred to me that (taking Bernhard's design and vibration notes as a starting point) the main baffle could be made to be removable when not listening to music. If wings are hinged they and the baffles could be folded flat and stacked against the wall when not in use.

I had in mind that with the driver supported from the magnet and with a small portion of the front baffle permanently attached, the larger portion of the baffle, supported by rubber bumpers could then be removable.

Finally, if it is acoustically desirable to turn Bernhard's bass box 45 degrees one could have a more reasonable in-room footprint for various occasions. For instance, in my room the TV can't be seen from all locations because of the hughe speaker boxes.

[Peter Daniel]

Originally posted by reverendclark
Another brave soul.

Alas, we're not going to impress Fertin with our buying power if there are only four of us. Do we want to keep this project among ourselves or expand it to the Joe List and Speaker Asylum as well, just to get more warm bodies?

Peter C

Any more interest with Fertin group purchase?

[reverendclark]

Well, I *still* am, but this thread seems to be fizzling a little, what with folk now going on about issues peripheral to that particular subject. I want to do this anyway. I can't seem to get Fertin's agent to respond but BlackForest Audio has responded, so I'll go ahead with them at some point, even if it's solo. We've got a pretty good 12v power supply setup that I'm dying to try, and this will save me from the Sierra Brooks/TAD 4002 thing on my next speaks.

But I'd be happy to go in with "enough" others to make it happen. A buck's a buck.

Peter C