At the present time I don't have any detailed images that have not been previously posted either here or at Pure Music Group's forum already:
http://puremusicgroup.com/yabb/YaBB.pl?board=FEAFORUM
One thing that might make a difference is that Nakamura-san's factory is able to cut their wood very precisely, and they glue up their enclosures all at once on big mechanized jigs that hold everything very securely. They don't use any screws, at least in the enclosures I've seen. (Joe's most recent enclosures were exceptions: I assume that they put in screws while the boxes were on the jigs so they could save time by removing the boxes from the jig quickly. They used "distressed" wood that they got from their wood supplier: it was cosmetically funky for speaker building since one side of the wood already had some kind of a finish applied to it, but structurally it was quite good, so they bought a few containers of the wood for projects or applications where looks are less important than saving money.)
-- Chris
http://puremusicgroup.com/yabb/YaBB.pl?board=FEAFORUM
One thing that might make a difference is that Nakamura-san's factory is able to cut their wood very precisely, and they glue up their enclosures all at once on big mechanized jigs that hold everything very securely. They don't use any screws, at least in the enclosures I've seen. (Joe's most recent enclosures were exceptions: I assume that they put in screws while the boxes were on the jigs so they could save time by removing the boxes from the jig quickly. They used "distressed" wood that they got from their wood supplier: it was cosmetically funky for speaker building since one side of the wood already had some kind of a finish applied to it, but structurally it was quite good, so they bought a few containers of the wood for projects or applications where looks are less important than saving money.)
-- Chris
13L box - some measurements
Been running a week now. The D5nf are mounted is a 13L box with vent. After getting WT3 I found the box was tuned too low so shortened the vent by 40% to get it back to the desired 45hz. It's still running in but can throw some heft in the bass. Treble is great. The attached is as measured in my room, at listening position. The room is untreated and there are a lot of reflections but it does illustrate the bandwidth. I cut the side going down to 10hz because the ground here shakes constantly. I had to do the measurements on a Sunday to get a halfways quiet environment.
Also tried different taps, 4/8 and 16 ohms. Best response is definitely 16ohms. Compared to 16 ohms the treble falls away 4db/20khz, 3.5dd/10khz, 1db/1khz, 2.5db/100hz, 3db/65hz. on the 4 ohm tap.
Brian
Been running a week now. The D5nf are mounted is a 13L box with vent. After getting WT3 I found the box was tuned too low so shortened the vent by 40% to get it back to the desired 45hz. It's still running in but can throw some heft in the bass. Treble is great. The attached is as measured in my room, at listening position. The room is untreated and there are a lot of reflections but it does illustrate the bandwidth. I cut the side going down to 10hz because the ground here shakes constantly. I had to do the measurements on a Sunday to get a halfways quiet environment.
Also tried different taps, 4/8 and 16 ohms. Best response is definitely 16ohms. Compared to 16 ohms the treble falls away 4db/20khz, 3.5dd/10khz, 1db/1khz, 2.5db/100hz, 3db/65hz. on the 4 ohm tap.
Brian
Attachments
Lack of measurements
I find it inconceivable that ANY manufacturer and/or designer could build a driver and expect consistent performance without testing them - can't be done unless by "golden ears" guesswork!
I'll bet that ICI test these little fellas to the last molecule!
Would you pay approx $4000 per item (minimum!!!) without knowing that they were tested by somebody that knows what they're doing, so you would have some idea of what you were buying?
Also, if the retailer is happy to sell the product without knowing it's satisfactory or not (!), what then constitutes a warrantee or any performance minimums at all, manufacturer faults, etc?
This must require SOME official specification, even if the TS parameters are kept "secret" (apart from a diyAudio "sim results").
They can't be that bad that no one will buy them (apart from the price!)- look at the Lowthers test results, and they've been selling drivers for many years!
Where are the official specs, accurate or not, for evaluation?
I find it inconceivable that ANY manufacturer and/or designer could build a driver and expect consistent performance without testing them - can't be done unless by "golden ears" guesswork!
I'll bet that ICI test these little fellas to the last molecule!
Would you pay approx $4000 per item (minimum!!!) without knowing that they were tested by somebody that knows what they're doing, so you would have some idea of what you were buying?
Also, if the retailer is happy to sell the product without knowing it's satisfactory or not (!), what then constitutes a warrantee or any performance minimums at all, manufacturer faults, etc?
This must require SOME official specification, even if the TS parameters are kept "secret" (apart from a diyAudio "sim results").
They can't be that bad that no one will buy them (apart from the price!)- look at the Lowthers test results, and they've been selling drivers for many years!
Where are the official specs, accurate or not, for evaluation?
Re: Lack of measurements
As the "official tester"
for Feastrex -- which is essentially a one-man garage maker supported by a few maniac parts suppliers on the production side and by a few crazy volunteers and a few fanatic business partners on the post-production side -- I suppose I ought to reply. The drivers will get tested when I am able to make time to learn how to use the software and hardware that Feastrex purchased from overseas to measure their drivers. The language barrier means that nothing gets done in this department until I do it since I'm the only person who understands English and who also has access (sort of -- it's a two-hour train ride from where I live) to all the drivers. Trouble is, I'm already working two jobs to support my wife and seven kids so it's hard for me to make time. This is an absolutely unacceptable situation from the perspective of many consumers and nobody can blame anyone for pointing out the things that you have written above. Fortunately it's a free world and nobody's forcing anyone to purchase anything that they feel uncomfortable with. Eventually, Lord willing, the situation will be rectified . . . Now, as to your comments:
Consistency is possible even without testing. Just use consistent components and assemble them in a consistent manner and you'll get consistent results.
If someone was to run a test and post the results here, would you have some idea of what you were buying? "Yes and no." There are very important things about audio transducers that a test cannot tell you. There is no denying that the numbers are relevant but there is an over-dependency among DIYers on numbers. You give people a certain set of numbers, which are then plugged into various simulation and design programs, and then certain design parameters are spit out. And then the user thinks that he knows how to use the transducer for best results. And he does . . . except that he doesn't. There is a lot to be said for doing things by ear. It's a pain but it will yield results that punching in numbers alone will never give you.
No retailer of Feastrex drivers sells them without first having confirmed to their personal satisfaction, through actual use, that the drivers are excellent. If anyone builds an enclosure according to Feastrex's specifications, the results will be very good indeed. It may not be the most scientific approach appealing to the guys in the white lab coats, but there's undeniable excellence in the sound emanating from those boxes.
These "official specifications" may not be what you're hoping for, but you can find some parameters here:
http://puremusicgroup.com/yabb/YaBB.pl?board=FEAFORUM
I hope this helps somewhat!
-- Chris
jameshillj said:
As the "official tester"
for Feastrex -- which is essentially a one-man garage maker supported by a few maniac parts suppliers on the production side and by a few crazy volunteers and a few fanatic business partners on the post-production side -- I suppose I ought to reply. The drivers will get tested when I am able to make time to learn how to use the software and hardware that Feastrex purchased from overseas to measure their drivers. The language barrier means that nothing gets done in this department until I do it since I'm the only person who understands English and who also has access (sort of -- it's a two-hour train ride from where I live) to all the drivers. Trouble is, I'm already working two jobs to support my wife and seven kids so it's hard for me to make time. This is an absolutely unacceptable situation from the perspective of many consumers and nobody can blame anyone for pointing out the things that you have written above. Fortunately it's a free world and nobody's forcing anyone to purchase anything that they feel uncomfortable with. Eventually, Lord willing, the situation will be rectified . . . Now, as to your comments:Consistency is possible even without testing. Just use consistent components and assemble them in a consistent manner and you'll get consistent results.
If someone was to run a test and post the results here, would you have some idea of what you were buying? "Yes and no." There are very important things about audio transducers that a test cannot tell you. There is no denying that the numbers are relevant but there is an over-dependency among DIYers on numbers. You give people a certain set of numbers, which are then plugged into various simulation and design programs, and then certain design parameters are spit out. And then the user thinks that he knows how to use the transducer for best results. And he does . . . except that he doesn't. There is a lot to be said for doing things by ear. It's a pain but it will yield results that punching in numbers alone will never give you.
No retailer of Feastrex drivers sells them without first having confirmed to their personal satisfaction, through actual use, that the drivers are excellent. If anyone builds an enclosure according to Feastrex's specifications, the results will be very good indeed. It may not be the most scientific approach appealing to the guys in the white lab coats, but there's undeniable excellence in the sound emanating from those boxes.
These "official specifications" may not be what you're hoping for, but you can find some parameters here:
http://puremusicgroup.com/yabb/YaBB.pl?board=FEAFORUM
I hope this helps somewhat!
-- Chris
To Test or Not to test
In the USA we have a term for this...
Buying a pig in a poke....
I bought my Pig (D5nf)... without even hearing them...(poke)
NO DATA
Nada
zip
zero
James, it boils down to this...
Sometimes you just have to jump off the cliff and see how it feels.
No risk...no reward.
In my case... I am one very happy dude...
Phil Townsend
Santa Fe, New Mexico, USA
In the USA we have a term for this...
Buying a pig in a poke....
I bought my Pig (D5nf)... without even hearing them...(poke)
NO DATA
Nada
zip
zero
James, it boils down to this...
Sometimes you just have to jump off the cliff and see how it feels.
No risk...no reward.
In my case... I am one very happy dude...
Phil Townsend
Santa Fe, New Mexico, USA
I'm very happy with my D5nf drivers, too. I've heard a bunch of great speakers over the years and at last year's RMAF, and I've never heard any that make me *feel* happier than these. In fact, I always feel cheered up while listening to them and afterwards. There's just nothing else like them.
I heard some really great speakers at RMAF last year, and I thought they all sounded wonderful, but when I went back to the Feastrex room and listened to them again, I suddenly felt that the other speakers had sounded kind of "electronic" while the Feastrex speakers sounded pure and natural and "organic." The other speakers left me feeling a little tired or anxious, while the Feastrex speakers left me feeling refreshed and happy.
Well, that's my 2 cents worth. I'm happily biased, though! ;-)
Mike
I heard some really great speakers at RMAF last year, and I thought they all sounded wonderful, but when I went back to the Feastrex room and listened to them again, I suddenly felt that the other speakers had sounded kind of "electronic" while the Feastrex speakers sounded pure and natural and "organic." The other speakers left me feeling a little tired or anxious, while the Feastrex speakers left me feeling refreshed and happy.
Well, that's my 2 cents worth. I'm happily biased, though! ;-)
Mike
consistency
Well high frequencies above 10K are the MOST difficult to measure accurately so I wouldn't be concerned about the absolute values of the graph above that number. Actually the RTA shows a lot of healthy action up to 25khz which is already a feat for Feastrex and way better than other drivers I've tested.
The attached shows an on-the-floor, quick and dirty measurement of the two drivers as received, fresh out of the box. Compared to other drivers we've tested, these are supremely well matched.
This is my subjective impression as well. Maybe we can't consciously hear many kinds of distortions, but when they are absent the body knows and relaxes. I also noticed this effect when after long term listening to digital sources and then changing to a good quality analog source the ears relax and there is just less tension.
Regards
brian
Well high frequencies above 10K are the MOST difficult to measure accurately so I wouldn't be concerned about the absolute values of the graph above that number. Actually the RTA shows a lot of healthy action up to 25khz which is already a feat for Feastrex and way better than other drivers I've tested.
The attached shows an on-the-floor, quick and dirty measurement of the two drivers as received, fresh out of the box. Compared to other drivers we've tested, these are supremely well matched.
This is my subjective impression as well. Maybe we can't consciously hear many kinds of distortions, but when they are absent the body knows and relaxes. I also noticed this effect when after long term listening to digital sources and then changing to a good quality analog source the ears relax and there is just less tension.
Regards
brian
Attachments
Re: consistency
Wow!
That is pretty darn good.
-- Chris
bcherry said:
Wow!
An externally hosted image should be here but it was not working when we last tested it.
That is pretty darn good.
-- Chris
Re: consistency
Hmm . . . right now somebody is practically giving away an Otari half-inch 4-channel machine on which channel 3 is showing unstable performance . . . I'm toying with the idea of getting a 2-channel conversion kit for it from JRF Magnetics . . . although how do you explain to your wife about a tape deck that weighs just shy of 100kg? . . . "It followed me home?"
bcherry said:
Hmm . . . right now somebody is practically giving away an Otari half-inch 4-channel machine on which channel 3 is showing unstable performance . . . I'm toying with the idea of getting a 2-channel conversion kit for it from JRF Magnetics . . . although how do you explain to your wife about a tape deck that weighs just shy of 100kg? . . . "It followed me home?"
Re: consistency
This is a pretty consistent experience and I think it's an
accurate indicator. We know that your brain is very busy filling
in gaps and making a coherent picture out of every audio
performance, and perhaps this relaxation is simply the brain
not having to work so hard.
bcherry said:
This is a pretty consistent experience and I think it's an
accurate indicator. We know that your brain is very busy filling
in gaps and making a coherent picture out of every audio
performance, and perhaps this relaxation is simply the brain
not having to work so hard.
Thunder from down under . . .
It seems that the Wizards of Oz are up to their (new) old tricks again . . .
http://www.stereo.net.au/forum/index.php?showtopic=5925&st=0
. . . gotta stay tuned . . .
It seems that the Wizards of Oz are up to their (new) old tricks again . . .
http://www.stereo.net.au/forum/index.php?showtopic=5925&st=0
. . . gotta stay tuned . . .
Just a couple of points to add to this section of the blog on Feastrex projects before I take a pause.
I prefer energetic treble so all the speakers here are either compression horn tweeter, Jordan 2" or ribbon.
I didn't have high expections for a whizzer but the Feastrex whizzer gives away nothing. It is smooth, energetic and very extended. It is among the best treble I've heard.
It must have something to do with the paper. I have some samples of the Feastrex paper here. It is not pulp based. Whereas you can easily poke a hole in pulp paper or tear it, this long fibre mulberry paper is VERY strong. Try to tear it and it is like tearing cloth. I can't imagine that you could poke a hole in these cones. I think pulp paper compared to washi paper is like mdf compared to real wood. Resonance, breakup and strength characteristics are totally different. I don't think any of those parameters are covered by TSP, are they? AFAIK they are more concerned with air piston behaviour.
I can imagine what a guitar made of mdf would sound like. I'm getting amazing full-bodied sounds on a cello recording (Yo Yo Ma Appalachian something).
My little box: a 13L ported box isn't very creative, i know, but as mentioned I wanted to see if this driver will work as someone might want to use these drivers but not have space for big boxes. Well they work very well. Maybe with a smaller box we hear less box and more driver. Yesterday a Feastex user came by and observed that the small boxes don't sound deficient at all compared to the usual size box this driver is used with.
Anyone in Hong Kong is welcome to come by my workshop and have a listen.
OK I've ordered some 22ohm output transformers just to test whether there might be any more benefit to be gained. I should have them in 10 days and will install and take some more measurements..
Regards
brian
I prefer energetic treble so all the speakers here are either compression horn tweeter, Jordan 2" or ribbon.
I didn't have high expections for a whizzer but the Feastrex whizzer gives away nothing. It is smooth, energetic and very extended. It is among the best treble I've heard.
It must have something to do with the paper. I have some samples of the Feastrex paper here. It is not pulp based. Whereas you can easily poke a hole in pulp paper or tear it, this long fibre mulberry paper is VERY strong. Try to tear it and it is like tearing cloth. I can't imagine that you could poke a hole in these cones. I think pulp paper compared to washi paper is like mdf compared to real wood. Resonance, breakup and strength characteristics are totally different. I don't think any of those parameters are covered by TSP, are they? AFAIK they are more concerned with air piston behaviour.
I can imagine what a guitar made of mdf would sound like. I'm getting amazing full-bodied sounds on a cello recording (Yo Yo Ma Appalachian something).
My little box: a 13L ported box isn't very creative, i know, but as mentioned I wanted to see if this driver will work as someone might want to use these drivers but not have space for big boxes. Well they work very well. Maybe with a smaller box we hear less box and more driver. Yesterday a Feastex user came by and observed that the small boxes don't sound deficient at all compared to the usual size box this driver is used with.
Anyone in Hong Kong is welcome to come by my workshop and have a listen.
OK I've ordered some 22ohm output transformers just to test whether there might be any more benefit to be gained. I should have them in 10 days and will install and take some more measurements..
Regards
brian
Re: Re: consistency
Pretty much the same experience here. The time, phase and point source info with FR does the trick, You don't get the music in pieces which tends to make you focus on/listen to details. Digesting the "whole" takes effort like a musician who is so focused on technique (usually "young-uns") or should I say technician. However, there are those who are able to blend everything into a "whole" captivates you from the first note to the last, leaving you with a performance you won't soon forget.
I guess, I'll have to find out how deep this rabbit hole goes. Besides, I like the company, you guys talk in terms I could understand. I wish I had as much "faith" as you guys, but I'm just a beginner unsure of what is "right" from "wrong." I'm getting stronger everyday, hopefully for the wiser.
bcherry said:
Nelson Pass said:
This is a pretty consistent experience and I think it's an
accurate indicator. We know that your brain is very busy filling
in gaps and making a coherent picture out of every audio
performance, and perhaps this relaxation is simply the brain
not having to work so hard.
Pretty much the same experience here. The time, phase and point source info with FR does the trick, You don't get the music in pieces which tends to make you focus on/listen to details. Digesting the "whole" takes effort like a musician who is so focused on technique (usually "young-uns") or should I say technician. However, there are those who are able to blend everything into a "whole" captivates you from the first note to the last, leaving you with a performance you won't soon forget.
I guess, I'll have to find out how deep this rabbit hole goes. Besides, I like the company, you guys talk in terms I could understand. I wish I had as much "faith" as you guys, but I'm just a beginner unsure of what is "right" from "wrong." I'm getting stronger everyday, hopefully for the wiser.
Paper used in the drivers
Just in case people were not aware, the whizzer cones and the main cones are made from two different papers. Both are handmade Japanese papers of the highest quality, but the main cone is made from the sub-bark of a member of the mulberry family (the Japanese term for it is variously transliterated as kouzo/kohzo/kozo) and the whizzer cone is made from Diplomorpha sikokiana ("ganpi" in Japanese).
I know the main cone paper is not an "off the shelf" paper (even for its maker Mr. Iwano), and I'm not sure but I think the whizzer cone paper is also order made to Feastrex's specs.
And then a huge factor in the sound of the drivers is the choice of varnishes used on them, and the way they are applied. This is an immense "dark art" in itself and several lifetimes could easily be spent researching this one area alone. Mr. Teramoto has no pretensions of being an authority on varnishes and finishing materials but he does devote a LOT of time and effort to research in this area. Really small changes in what you do and the way you do it can end up having a huge effect on the sound.
The higher temperatures of the field coil drivers tends to make their glues cure to full hardness relatively quickly, but Mr. Teramoto thinks that with the permanent magnet drivers, the treble is the part that improves the most as the glue cures to full hardness, so it will be interesting to hear from you whether you (Brian Cherry) continue to hear an improvement in the treble over time.
-- Chris
Just in case people were not aware, the whizzer cones and the main cones are made from two different papers. Both are handmade Japanese papers of the highest quality, but the main cone is made from the sub-bark of a member of the mulberry family (the Japanese term for it is variously transliterated as kouzo/kohzo/kozo) and the whizzer cone is made from Diplomorpha sikokiana ("ganpi" in Japanese).
I know the main cone paper is not an "off the shelf" paper (even for its maker Mr. Iwano), and I'm not sure but I think the whizzer cone paper is also order made to Feastrex's specs.
And then a huge factor in the sound of the drivers is the choice of varnishes used on them, and the way they are applied. This is an immense "dark art" in itself and several lifetimes could easily be spent researching this one area alone. Mr. Teramoto has no pretensions of being an authority on varnishes and finishing materials but he does devote a LOT of time and effort to research in this area. Really small changes in what you do and the way you do it can end up having a huge effect on the sound.
The higher temperatures of the field coil drivers tends to make their glues cure to full hardness relatively quickly, but Mr. Teramoto thinks that with the permanent magnet drivers, the treble is the part that improves the most as the glue cures to full hardness, so it will be interesting to hear from you whether you (Brian Cherry) continue to hear an improvement in the treble over time.
-- Chris
Thanks Chris for describing the difference between the cone and whizzer paper and the treatments.
Actually the word 'paper' doesn't seem to tell the right story. Maybe we need another word for this 'stuff'. Teramoto was describing how it is crumpled up and used to wipe a sword blade. I also scrunched and kneaded a ball of it and notice it becomes soft like linen.
I look forward to more improvements in the sound.
BTW, I think your TSP are reasonably accurate. But they don't really convey the important things here.
Regards
Brian
Actually the word 'paper' doesn't seem to tell the right story. Maybe we need another word for this 'stuff'. Teramoto was describing how it is crumpled up and used to wipe a sword blade. I also scrunched and kneaded a ball of it and notice it becomes soft like linen.
I look forward to more improvements in the sound.
BTW, I think your TSP are reasonably accurate. But they don't really convey the important things here.
Regards
Brian
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