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Bigun 7th December 2010 06:09 PM

can FH3 beat out the Onken ?
This is a question partly aimed at Chrisb - the man who's built 'em all. The application is for a SET amplifier so sensitivity matters (Mark Audio is not preferred because of this).

With the demise of the FE127 we can no longer make the original Fonken. And I remember that Chris thought very highly of the Fonken, preferring it, by a whisker in some cases, over most others. I understand that the Fonken not only does most things very well but also offers some 'magic' to the music. Others have tried to win hearts and minds, but are either too big or suffer from tradeoffs or simply don't offer the same kind of 'magic' that the Fonken was able to deliver.

So my questions to those who may know are:

Is the FH3 to become the new preferred choice ?

If it's not the FH3, what are the top contenders ?

.....and we have to be careful not to overate the FH3 on account of its being such a nice looking design and the latest item of interest.

chrisb 7th December 2010 08:14 PM

gee, no pressure "it's OK Chris, this is off the record" ;)

Well, "F" of onken did originally refer to "Fostex" and the FE127 /167 or FX120 / F120A & FF85K were definitely more well suited to this enclosure topology than other models then or still in the Fostex full range model line. But as with many well executed and flexible architectures, the basic design has proven to work quite well with a variety of other drivers, most recent examples with which I'm intimately familiar being the Mark Audio Alpairs (7/10/12), and CHR & EL70. These work very indeed, but as you've indicated, their sensitivity is not so well suited to "flea watt" SETs.

To my ears, the FH3 or the Woden Valiant with current FE126En would be a great match with low powered tube amp - either are easily capable of filling even a "largish" space ( 400ft^2)

However, given a choice and adequate power such as at least 12-15W EL84, I'd opt for the "F"onken (or with the Mark Audio drivers "Mar"-Ken; the latest Alpairs 7& 12 are very interesting ) in terms of finesse, ease of room placement and domestic acceptance. Indeed, 2 of my current systems are FE127E and FE167E of that design (the 3rd is dual EL70 in the MicroTower)

how's that for not answering the question?

planet10 7th December 2010 08:30 PM

Given the options and the contraints, Yes. And i imagine that careful suprabaffle design would give the same low diffraction signature that the wide champher on the fonken-style boxes confer. Hard finished, carved foam, that gives the driver the appearance of being on the blunt end of a teardrop with the FH3 stuffed into the bottom could take it a step further.


bigfishe 7th December 2010 08:53 PM

What is diffraction anyway?

planet10 7th December 2010 09:47 PM

Diffraction is the behaviour of the soundwaves as they hit a discontinuity. Effects differ depending on the relation between the wavelength size and the relative size of the discontinuity.

Specifically, at high frequencies, a wave travels along the baffle and hits the edge, it then reradiates, and is time delayed by the time of travel across the baffle. A champher or radius on the baffle edge dramatically reduce that, the bigger it is, the lower in frequency its affect. The artifacts from this diffraction leas to the ear/brain being able to easily locate the speaker.

At low frequencies, you get baffle step. Most people imagine bafflestep as a smooth transition to a lower level, but the transition has ripple, how much depending on the shape of the baffle/box. In the top left you see the classic sphere (front part of a teardrop. In the botton-right the shape used on Ron\'s Austin\'s and a common sB used on Frugel-Horn.

In-between you have a hybrid.

A teardrop shape is one of the best shapes for minimizing all these artifacts.


brucegseidner 7th December 2010 10:01 PM


Originally Posted by bigfishe (
What is diffraction anyway?

I was never very good at them, but it is a type of division where one imagines a pie and taking slices of which to compare other slices of other pies or something like that. Really, never made much sense to me why anyone would take a quarter of a pie and wonder how many slices a pie cut to some other number would compare. I mean pie is pie and I am not one to complain if my brother's slice is a 64th larger or anything.

Bigun 8th December 2010 12:38 AM


Originally Posted by chrisb (
how's that for not answering the question?

very diplomatic :cool:

I guess I have to wait til more folk have heard the FH3...

chrisb 8th December 2010 05:52 PM


Originally Posted by Bigun (
very diplomatic :cool:

I guess I have to wait til more folk have heard the FH3...

build a pair yourself from particle board (dirt cheap for a prototype);lot less work than a full fledged Fonken (i.e. less than a day in the shop if you're not worried about furniture grade finish or flush mounting drivers), and then you can answer your own question :happy2:

of course we all need to remember that YMMV, etc.

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