Just placed my pre-order..

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for the Fostex FE166 ES-R from Madisound..

It will be interesting to see what the sound quality is like. (I'll try to test them when I get them and provide results - expected around mid-feb.)

Considering the materials it a freak'in bargain. Both Cobalt and Lanthanum are VERY expensive rare-earth elements with generally better (smaller) crystal structures and capable of higher gauss. Both of these attributes are associated with better sound. Then pop-in the bonus of the voice-coil material which should reduce oxidation (particularly the non-conductive variety) and again reduce crystal structure problems.

wonder if Pass (and friends) have placed their order yet?
 
I have had this driver for a few weeks. It was a sample sent to Madisound for eval. You will definately be pleased with it. I have not had it in a suitable enclosure so my listening has been "open", still it's obvious that it is *special*. Expect full bass and wide open highs and amazing power handling. I would also reccomend the factory cabinet or backloaded horn of similar length.

TC
 
cool..(drool). Late Jan./early Feb. seems like eternity now.

As for enclosures I'll be doing something VERY different to get the best midrange possible. It will have an "expansion" but the termination will be closed with aperiodic venting. Targeted response will be 200Hz and up. I'll probably add a piezo in an odd-manner for the highest freq.s. Dipole pro woofers below 200Hz. Powered T-Line for freq.s below 50Hz.

Now I need to go convince BrianGT to produce a current gain-clone monoblock kit..
 
supertweeter Bill, supertweeter.

In particular I'm thinking of making one omnidirectional. i.e. cut the horn flare off and fire it upward into a 360 degree reflector. (..yup, I do think a bit differently). This should provide a steeper acoustic high-pass to the piezo while giving the speaker more "air" and hopefully a more linear response off-axis. Besides, its a cheap tweak (if it sucks it finds its way in the trash without real regrets).

Here is a minimalist comercial design that uses a piezo (note the difference in remarks between the trio and other loudspeakers):
http://www.tnt-audio.com/ampli/anniversary_e.html
 
I gave a materials basis reason. TC gave a subjective reason.

But I'll throw in a comparison vs. more costly drivers.

Notice the impressions here between some Fostex drivers and Lowther drivers.

http://www.quarter-wave.com/Projects.html

another here (in pdf form only):

http://www.firstwatt.com/images/current_amps/CurrentSourceCrossoverNetworks.pdf

Note that both "reviews" are completely aware of the differing response variations of the drivers, but also realize that the response deviations from linearity are NOT the reason for the preferred sound. So what is?

The major difference between a lowther and a fostex is the magnet (though there are different types of magnets for different speakers throughout their line). In particular the major difference is gauss (or the strength of the magnet). However crystal structure is also important.

The reason why is related to voice-coil control.

The stronger the magnet (and the way its used) the more control it "should" have (though back emf can be problematic with any loudspeaker, also the way the magnetic field is "focused" can alter the "equation"). Most drivers have no more than 1.2 gauss. Some of the lowther "beaters" have gauss ratings up to 2.6 gauss. (It should be noted that most magnetic material will not hold a gauss rating over 1.2 for any substantial period, and the material that does is VERY expensive by comparison.)

Crystal structure (of the magnet) is also important for unifomity of the magnetic field. Uniformity can be substantially bettered via an electromagnet - enough so that a driver with an electomagnet only having a (good) gauss of 1.2 could subjectivly better a driver with a much higher gauss. Most "normal" magnets, (non-electromagnets), are a mixture of materials. The cheaper ones are ceramic, the more expensive are Neo. (rare earth), the most expensive are those utilizing more precious materials such as Cobalt. Often though these very expensive magnets have very little of the precious material - but its enoug to make a difference (both in actual cost and qualitative difference). When combining these expensive materials with the base (usually iron), the crystal structure changes (as does the ability to accept and maintain a magnetic field). Crystal structure usually becomes smaller and perhaps more uniform. I can't say though if this is because of the "processing" itself or the "material blend" (but its probably both). This in turn allows a more uniform magnetic field. Now it should be obvious that ceramic magnets generally have larger less uniform crystal structures, with resulting poorer magnetic fields and ultimatly lesser sound quality. Neo Magnets come in second here, with good quality "precious" magnets in first place. (The best would be an electromagnet with a nano-crystal structure - i.e. an amorphous electrified magnet. Unfortunetly I don't think such a thing exists.)

Now back to the F 166e vs. the esr. Disregarding the differneces in voice coils, the esr version "should" have a higher gauss and a smaller more uniform crystal structure for the magnet. This in turn should provide a subjective "upgrade" similar to what Martin King described when changing the fostex for a the more costly Lowther.

In otherwords you should be getting one of the better Lowthers "on-the-cheap", BUT without the severe response deviations that the lowthers have. (though bear in mind that the fostex has them as well - its just that they are not nearly as pronounced.)
 
FE166ES-R

Besides the recommended cabinet on Madisound's site I have unearthed a Japanese site which is of the opinion that the D-37, (typical Japanese style BH), D-168 (Swan style and my favortite style) and the Nessie JrcEs (which is not the original F2000 but one which is slightly larger in area) would be suitable.

I am of the opinion that the
D-66 which is a double driver horn would also work.

I am also looking for a copy of the Nessie JrcEs plan so if anyone would
like to share it please let me know.

ttfn

Andrew
 
The part of this exercise that I find somewhat "strange" on the part of Fosex is why a
fancy motor assy (magnet & voicecoil) but yet the usual main cone and whizzer as well as a stamped frame.
Why not the Hyper Parabolic cone as well ? Or even the HP cone and no whizzer?
Is there some synergy here with the motor and cone ? Or is it manufactured to a specific price and not neccesarily all that it could be ? They are made in limited numbers and from what I read the domestic market quantity has already been consumed in Japan so price should not be an issue.
The new EZ Sigma series have the new cones so ...?
With a strong motor and such power handling I would have thought the HP cone and cast frame would have been a given.
Maybe the sound of the HP cone is not so popular?
Truth be told I think its very resonably priced but also wonder if perhaps they will introduce another version later, maybe 2005 ?
I am undecided as to whether or not I will order a pair, maybe by the time I decide and try to order a pair they will be finished :bawling:
I am still awaiting a FE208SS replacement, that, is what I want.

Andrew
 
Andrewbee said:
Maybe the sound of the HP cone is not so popular?

I think this is the reason exactly. Or more to the point, Fostex does something rather unusual in marketing - giving the customers what they asked for.

I think the only thing they left out was the ability to use the optional brass issolation ring frame on the EZ models (something I believe is quite desired in Japan despite the absurd price). Chances are though that they balanced the need for price against the need for the frame, (and price won).

If I'm right the 208SS was the double magnet version of the old S? If so, then chances are IF a 206ESR is produced it would be considerably better (better materials - no doubt similar gauss), and would be the natural successor to the 208SS (by virtue of its horn-"dome" as opposed to the "pure" dome of the EZ). I think the 208ES was the special edition version of the EZ, which had the dual magnet and is no longer available. As far as I know NONE of the older models had magnets that were anywhere near as good (material-wise), except of course for the f200a and f120a (and even though having a magnet made of superior materials, gauss was not high to keep freq. linearity).

In any event I don't expect a truely better product will be available from them for quite some time at this low a cost. It is possible that they will make a 206ESR, but this will not neccesarily be a better product. Even if they do produce such, will it be available at a reasonable cost including shipping? I think its unlikely unless Josh at Madisound sells-out this supply. Otherwise you'll have to import from Japan direct at F A R greater expense (if indeed you are able to).
 
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