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Exciting new line of fullrange drivers from Feastrex

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I heard the 9" with the drum cd they had in the room and it was pretty amazing. Only if this driver didn't cost so much.

The 5" in the maxxhorn to me did everything we threw at it pretty damn good and wouldn't say it was toobright. We had a Janis Joplin disc we tried in most rooms we entered and it exposed brightness on allot of systems and the maxxhorn did a good job with it.

These shows really make it hard to evaluate with the traffic in and out, talking going on, people moving around, hotel room setup, and everything else going on in the rooms.

I was fortunant to get a couple of after hours listening with the maxxhorn and what a pleasant experience it was, Bob Spence is one hell of a gentleman to get to know. Allot of mechanical fixes went into his no xo horn to really get this driver to do it right and it shows that this driver is all it's out to be in the right enclosre if you had the funds to acquire it.

BR
 
I was fortunant to get a couple of after hours listening with the maxxhorn and what a pleasant experience it was, Bob Spence is one hell of a gentleman to get to know. Allot of mechanical fixes went into his no xo horn to really get this driver to do it right and it shows that this driver is all it's out to be in the right enclosre if you had the funds to acquire it.

Yes, Bob has put a tremendous amount of work into developing his enclosure and I believe it has paid off. As a disclaimer, I will state that Bob is a good friend of mine, but I honestly think his was one of the top two single-driver speakers at the show.

John
 
So the claims of the Feastrex sounding fantastic in sub-optimal enclosures is?..

Please understand, I do not intend to be cynical; it may seem that way when some of my questions are juxtaposed against some of the more, er, excited posts.

Many claims have been made for these expensive drivers - I am trying to consider the emerging wide range of experiences. From folks' feedback, it is seems likely these are excellent drivers; excellent (and not so) in which ways, and in which contexts, is what I am trying to get a feel for.

I know, the only way I can 'know' is to listen - however, even that is very-much context-dependant.

Keep the info/experiences coming.

Regards
 
I think if one would be buying those magnificent drivers one should be also prepared to develop and build better (optimal?) cabinets for them...I mean, this DIYaudio forum, not "buy-it-yourself audio forum".

I feel that all the shown boxes are sub-optimal...
Square boxes, puajjj!
(but who am I to criticize).

Can we predict, from published data, which enclosures are ideal for them?

Cheers,
M
 
rcdaniel said:
So the claims of the Feastrex sounding fantastic in sub-optimal enclosures is?...

Which "sub-optimal" enclosures do you have in mind, and in what way are they "sub-optimal"?

I find it interesting that some people have said the 9-inch drivers sounded excellent, while the 5-inchers were disappointing, and others said just the opposite. And that's also true for some other speakers shown at this year's RMAF too. For example, some people loved the Yokohama Bayside speakers while others hated them. Some people thought the Linkwitz Orions were fantastic while others disliked them, and likewise for the Oris speakers and the Raal Omnis -- and that's hardly an exhaustive list. I get the impression that just about every speaker that really pushes some people's buttons is going to turn some other people off.

*****************

I just got a memo from my friend who was interpreting for Feastrex at RMAF this year. He said that one fellow who was extremely enthusiastic about the 5-inch speakers nevertheless observed that there was one very specific kind of low-frequency percussion instrument on one of his CDs that the enclosures could not reproduce well, and he had brought that CD precisely because most speakers (even at RMAF) have difficulty reproducing it. The problem in this case is attributable to comb effects you get in the bass region with a straight horn, and the fellow felt that it was not at all objectionable for music listening because you are almost never faced with situations where a suckout at one narrow frequency in the bass is going to stand out. At any rate, that would count as one fellow who simultaneously said that he thought the sound was fantastic, but also that the enclosures were less than optimal (at least insofar as there are some comb effects in the bass region).

*****************

Here is another memo I got from another friend: "Feastrex are very revealing speakers so any defects in the recordings will tend to come through very prominently. It is common for copied CDs to have more grain and hardness than the originals, and this needs to be taken into consideration. One day I had a friend who brought over a lousy Chinese copy of a popular female vocalist to listen to on my Feastrex field coil drivers. Surprisingly we enjoyed the CD from the 1st track to the last song. My friend was shocked that even though it was a bad recording, the music could come through so easily. When he left I checked my speakers and realized that I had turned the field coil voltage setting down to the minimum level for my power supply! When the voltage is set to the minimum, you give up some speed, detail and transparency, but the sound will be much more forgiving of defects in the source material. I now have an instant solution to less-than-optimum CDs -- just turn down the voltage setting. I remember Mr. Teramoto saying something to the effect that first-time users should start with the voltage set on the low side and then experiment in pushing the voltage up higher; it is possible that perhaps Feastrex at RMAF might have been pushing the voltage a bit too high, at least for some source material. I myself have backed away a bit from the maximum voltage setting for most of my source material, as the speakers become fairly unforgiving at the highest voltage."

-- Chris
 
(This post is being inserted here in the running Feastrex thread so that I can link to it from the Stereophile blog.)

I don't have any sort of a business relationship with Feastrex, but I do happen to live in Japan and am big fan of their products, and I am quite familiar with what goes into the making of the Feastrex drivers. so I would like to respond to one individual whose comment suggests he is incensed about the price.

All aspects of the Type III field coil drivers that were demonstrated at RMAF 2008 are "extreme." The frames were machined from solid billets of phosphor bronze. (These billets start off weighing 30kg each in the case of the 9-inch drivers; for the 5-inch drivers they would be proportionally smaller.) The field coils in the motors were wound from square wire, a very expensive technique. However, the single greatest contributing factor to the cost is the use of Permendur in the motors. The yoke, top plate, and pole piece -- in short, everything in the motor other than the field coil itself -- was milled from solid Permendur. Anyone interested in getting an idea of what Permendur raw material sells for can start clicking on the page at the following link:
http://tinyurl.com/4apvon

I can't link directly to the pricing information, but if you click on the additional link at the referenced page you'll see that, for example, two rods of Permendur measuring 25.4mm diameter by 100mm each cost approximately US$1,380. Now that would be the approximate raw material cost for the pole pieces of a pair of 5-inch Feastrex Type III (i.e., all-Permendur) field coil drivers, but in addition to that, the top plates contain even more Permendur material than the pole pieces, and each of the yokes are milled from a VERY large piece of solid Permendur. I could go on . . . I have seen the paper used in the cones selling for about $50 per sheet, and then there is the high cost of the urushi lacquer used on the bronze frames and phase plugs. Add it all up and even before any labor costs are figured in, the price tag for the raw materials in the drivers alone must be in the neighborhood of $10,000 for the pair. (I have not heard from anyone at Feastrex what their actual costs are, but anyone can do the math.) And the labor costs are considerable, I'm sure, considering that it is all highly skilled labor in Japan, of all places. Permendur is notoriously difficult to machine, especially when it has continuously curving, rather complex shapes such as are found on the inside of a Feastrex field coil motor. After machining it must be annealed, typically in a hydrogen atmosphere in which the temperature is brought up to close to the melting point of the metal and then very carefully and precisely cooled down over the span of about eight hours.

The enclosures are no less laboriously made. The best grades of Japanese urushi lacquer are extremely expensive and all faces of both the inside and outside of the enclosure have as many as 40 coats applied. After curing, each coat of urushi is carefully hand-polished before the next coat is applied. Considering that the curing time for each layer is typically four to eight hours, it would not surprise me in the least if it took two months to make a pair of enclosures. They are costly, but the price is not at all high relative to the labor, level of the workmanship and the huge surface area that had to be covered. I doubt it would be possible to approach a skilled Japanese urushi craftsman directly to have similar enclosures produced for a lower price.

I have not heard these loudspeakers so I cannot begin to venture a guess as to whether they represent good value or performance for the money, but when the products are properly understood the price is entirely understandable. These speakers represent the pinnacle of no-holds-barred, hand-crafted quality throughout. Are they affordably priced? Not for most people! But at the very least, I do think they are understandably priced. I wish I could have been there to hear them!

Christopher Witmer
Millennium Arts International LLC
Tokyo
 
...

I was there representing Feastrex, and I heard the urushi enclosures from the first to the last day.

When we first started playing them, they had some solid resonance issues in the midrange. To my ear, it sounded like internal cabinet stress of a mysterious cause. I was unsure of the cause, as they had sounded much better when I heard them in Japan. Later in the show, the resonances started to diminish, I had the notion that it was a humidity adjustment thing. Denver is VERY dry. Japan is humid. So as the panels were adjusting, de stressing themselves, the sound was getting better. The last day of the show, the sound was by far the best. this was, I personally feel, due to the humidity adjustment of those cabinets. There were other aspects of the systems that needed to be broken in. Just like the stuff of every other manufacturer, except a little more sensitive perhaps owing to the raw efficiency of the driver units.

Thanks to all who showed up. It was a fabulous show because of all the friendly people who were there. I hope that lots of people are inspired to go out and build some cool speakers now. I certainly am...

-Clark
 
Scott,

Yes, I did receive them. been reestablishing myself stateside lately, catching up... the customer emails that I have been getting tend to outweigh priority wise the "tweaker friend" emails, no offense. then there is the time in the shop building things... new things... muahaha! The website is about to get updated... stay tuned. So yeah, running a business is all engrossing. Ill get a pair of those tiny drivers you mentioned and start playing soon. let you know what I think.

Later dude,

Clark
 
Field coils for mental health

At the risk of going a bit off topic, here is an interesting application for field coils:

Man 'roused from coma' by a magnetic field

So you see, field coils are not just for music . . . they also also can be used to stimulate the human brain directly!

Hmm . . . I wonder what might happen if a field coil was used to excite one's ahem! "pole piece" . . . this may be a new business idea for Feastrex:

Thanks to the new Feastrex Permendurection NF-SEX, my marital life has never been better! WAF is a full 10/10! Only problem is, now we spend so much time in the bedroom that I hardly have any time left for enjoying music in the listening room!

-- Chris
 
Variant on Poindexter's Music Machine a big hit with Feastrex fan

I just found this in my mailbox, from a long-time lover of SET amplifiers:

Subject: PP Amplifier on the D9e drivers -- WOW!!! 😱

Hey Chris, one of my friends is a DIY amp builder and he brought over his 7591 tube PP amp based on Poindexter's triode wired, no feedback circuit. We hooked it up to my D9e-I drivers and I'm blow away by it.

The midrange is warm and rich . . . I hate to say it but I prefer it to my 300B SET. However, the best part was the bass and the control this thing delivers . . . Wow!! We played a traditional Chinese drum CD that is a real challenge for both bass and dynamics and my windows and ceiling were shaking. I didn't expect the difference to be so great.

So it looks like I'll be getting one of these 7591 PP amplifiers as soon as possible. I'll try to use excellent quality parts to implement the design at the highest level.

In my opinion the D9e drivers are capable of tremendous scale and power if given the correct amplifer to push them to the max. Although I have long been a died-in-the-wool SET lover, I now think that perhaps a good quality PP tube amp might be a better match than a lower powered SET.


Chris' comment on the above: I'm quite ignorant about tube amps. I'd love to get into them but frankly I'm afraid of She Who Must Be Obeyed . . . But I find it interesting that PP amplifiers -- not necessarily hugely powerful ones by any means -- are Mr. Teramoto's personal favorites for use with the Feastrex drivers. Which isn't to say that he dismisses other topologies (far from it) but his personal favorite happens to be PP. In fact, it was his strong personal preference for his personal PP amplifier that made him decide to bring a prototype to RMAF this year, and apparently it was well received. (It was used together with the 5-inch drivers in the urushi enclosures.) Anyway, while it would be silly of me to try to "sell" one amplifier typology as superior to another simply on the basis of second-hand reports, I thought I should mention this as something you SET lovers might want to consider looking into. I'm under the impression that an amplifier like Poindexter's Music Machine should not be all that expensive to DIY, even using parts of respectable quality. As for Mr. Teramoto's amplifiers, I have not heard the latest implementation that he took to RMAF but I remember his early prototypes sounded wonderful despite using only very run-of-the-mill parts.

FWIW, YMMV, etc.

-- Chris
 
Thankew, thankew, as it were.

There's no fundamental reason that a PP circuit cannot have high color of timbre (what Srajan calls 'tonal density'); it's a matter of design and implementation, same as any amp.  SE and PP circuits have different strengths and weaknesses in their basic designs, and so the process of maximizing the strengths and minimizing (or sidestepping) the weaknesses will be different, that's all.

mmThumb08.jpg


The original 6V6 Machine produces about five watts steady state output at the onset of clipping, so it may very well be sufficient for any Feastrex system unless playing into a very large and absorptive room, and satisfies the minimalist green impulse.

The reason some guys were exploring the 7591 was that it is a bigger power tube that's e-z drive like the 6V6.  This because the original 5965 front end was not able to supply enough voltage gain to drive any of the more usual suspects direct-input.  With the new 6GK5 front end, we get about 60% more gain, increased linearity, and lower noise. In this case, I would recommend rather the EL34, which is more linear and much more available. I have two breadboards of this circuit operating, and the first commercial build coming up. It produces about sixteen watts if you need such brute urge, and sounds, to me, at least as transparent(maybe more).

If anyone here is interested, I have posted schematics for both circuits over on tubes, which you can search up.  If there's interest, I can post them in this thread as well.  I would rather, than e-mailing them to lots of guys individually.  It's a simple circuit, eminently buildable.

Of course, if you are a well-heeled appreciateur of art objects (and why would a Feastrex follower not be?), I can scratch that itch, etc.   Bu-ut, this being a DIY zone, that's another story.

Best Aloha,

Poinz
AudioTropic
 
hey there...

Hi Poinz, We have one of your audiotropic pre-amps at Lovecraft Designs/Cain and Cain... still sounds great. I need advice on tube rolling. when/if you get a chance, please email me and walk me through a few things...

OK,,,,,

now announcing........THE NEW!!!!!!! MUCH IMPROOOOOVVVVVEEEEDDDD~~~~~!

Feastrex.com

Please visit this new site. I wrote it with the specific intent of answering so many of the plethora of questions out there about these unique drivers.

So yes, please visit the site, imform yourselves, be merry!

Good night.

-Clark

P.S. Please note that I am posting the site here for the purpose of information only. I no longer profit from the sale of Feastrex as I am now located back in America working in my own company. It was my project to make Feastrex a website (and measure the drivers, but hey...1 of 2 aint bad...). I tried to write it in as educational of a manner as possible. Many of the topics addressed there will prove to be very interesting for people to do more of their own individual research on. So yes. Please understand that this is not a solicitation, and please enjoy.
 
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