911 called back to say they couldn't help
Just to dig a little deeper: The solidity of the D5e in presenting these bells is like a mountain - absolutely unmoving. What a feat that paper can give the ultimate sound of metal! Little boxes, little cone - huge sound.
Just to dig a little deeper: The solidity of the D5e in presenting these bells is like a mountain - absolutely unmoving. What a feat that paper can give the ultimate sound of metal! Little boxes, little cone - huge sound.
Seriously, Joe, thanks for the heads up on that recording. I had never heard of it before but it sounds like it would be good to have.
Chris,
The image of "head inside temple bell" is perfect.
Where were the photos of the freddy with the curved vent taken? These look like Mr. Nakamura's work. Is that correct?
Thanks,
Joe
The image of "head inside temple bell" is perfect.
Where were the photos of the freddy with the curved vent taken? These look like Mr. Nakamura's work. Is that correct?
Thanks,
Joe
Yes, Joe, Mr. Nakamura cooked those up at Mr. Teramoto's request. That's the Feastrex head office listening room.
-- Chris
-- Chris
"Everything sounds good on both the D9e II and the D5e II. The D5e II seems to have the more perfect balance, more open top end, but still incredibly rich and full, and it goes quite deep. It is a remarkable achievement"
Dear Joe
Thank you so much for your sharing your experience. Which rock is classic rock according to you.
Dear Joe
Thank you so much for your sharing your experience. Which rock is classic rock according to you.
Re: Call 911
Agreed, so found a MP3 sampler and watched using Windoze media player's graphic equalizer and it didn't show me much compared to my reference: http://www.telarc.com/gscripts/title.asp?gsku=0136&mscssid=WQQ0BBEX1W9J8L46FVMVEG2G13201HN2
I realize a MP3 leaves much to be desired, so don't know how complex the 'Golden Bowls' CD is, but what can they do with a well recorded pipe organ symphony and concerto with the understanding that the extreme LF will have to be bypassed?
GM
talawalla said:
Agreed, so found a MP3 sampler and watched using Windoze media player's graphic equalizer and it didn't show me much compared to my reference: http://www.telarc.com/gscripts/title.asp?gsku=0136&mscssid=WQQ0BBEX1W9J8L46FVMVEG2G13201HN2
I realize a MP3 leaves much to be desired, so don't know how complex the 'Golden Bowls' CD is, but what can they do with a well recorded pipe organ symphony and concerto with the understanding that the extreme LF will have to be bypassed?
GM
Classic Rock
The Who, Pink Floyd, Yes, The Doors, Aerosmith, Van Halen, Beatles, Stones, U2 etc.
If this was the main diet I would probably recommend seeking a subwoofer that "did no harm". Probably difficult to achieve, but I believe there have been some advances in subwoofer technology in the last few years, so I wouldn't rule it out a priori. At the very least a survey of potential mates would make for an interesting read.
The Who, Pink Floyd, Yes, The Doors, Aerosmith, Van Halen, Beatles, Stones, U2 etc.
If this was the main diet I would probably recommend seeking a subwoofer that "did no harm". Probably difficult to achieve, but I believe there have been some advances in subwoofer technology in the last few years, so I wouldn't rule it out a priori. At the very least a survey of potential mates would make for an interesting read.
Pipe Organ
GM,
Certainly there can be nothing more taxing than a pipe organ symphony. The Bowls do not go as low as a pipe organ, but the test is, how cleanly and coherently can a system reproduce the complex interactions of the bells. I have heard many gradations of performance, but the D5e is by far the finest.
I do have a couple of solo pipe organ recordings, but haven't listened extensively. The D5e will give you the sense of the pedal tones, but not the full impact.
Track 6 of A.H. Rahman's sound track of 'Warriors of Heaven and Earth' begins with an Erhu solo followed by tremendously explosive taiko drums. The impact and solidity of these on the D5e Type II is breathtaking.
Track 13 of Ennio Morricone's soundtrack from 'The Mission' has a huge drum played at long intervals that seems to emanate from a point in space and grow to encompass a much larger space. When I used to listen with subwoofers, this was quite huge. The D5e does not reproduce its hugeness.
While I believe the D5e Type II to be the most perfect transducer I have heard, it must have some limitation. So the question we face is, do we compromise by loosing the extreme bottom end, or do we compromise by risking muddying the waters with other drivers, subs etc. It may be possible to extract more bass from the one driver, but my sense is that as you direct more and more of the effort of the enclosure to extract bass information the more, at a certain point, the mids begin to loose life. In other words, there is no free lunch no matter which way you turn..
GM,
Certainly there can be nothing more taxing than a pipe organ symphony. The Bowls do not go as low as a pipe organ, but the test is, how cleanly and coherently can a system reproduce the complex interactions of the bells. I have heard many gradations of performance, but the D5e is by far the finest.
I do have a couple of solo pipe organ recordings, but haven't listened extensively. The D5e will give you the sense of the pedal tones, but not the full impact.
Track 6 of A.H. Rahman's sound track of 'Warriors of Heaven and Earth' begins with an Erhu solo followed by tremendously explosive taiko drums. The impact and solidity of these on the D5e Type II is breathtaking.
Track 13 of Ennio Morricone's soundtrack from 'The Mission' has a huge drum played at long intervals that seems to emanate from a point in space and grow to encompass a much larger space. When I used to listen with subwoofers, this was quite huge. The D5e does not reproduce its hugeness.
While I believe the D5e Type II to be the most perfect transducer I have heard, it must have some limitation. So the question we face is, do we compromise by loosing the extreme bottom end, or do we compromise by risking muddying the waters with other drivers, subs etc. It may be possible to extract more bass from the one driver, but my sense is that as you direct more and more of the effort of the enclosure to extract bass information the more, at a certain point, the mids begin to loose life. In other words, there is no free lunch no matter which way you turn..
I was browsing about and noticed that Scott put the Freddie Chang enclosure on his site with a PDF download. What's of note is that the location of the driver has changed, actually pushed to the top of the baffle board. This is quite different from what everyone has built. Any particular reason for the change?
http://homepage.mac.com/tlinespeakers/FH/download/FreddieChang-map-040308.pdf
Regards, KM
http://homepage.mac.com/tlinespeakers/FH/download/FreddieChang-map-040308.pdf
Regards, KM
Thanks Scott, sorry.... my bad. Do you know who has built the updated version so far? I'm game to try..... as it also gets the driver higher off the floor towards ear level. I do wind up sitting on the floor for listening now and then ;-).
Regards, KM
Regards, KM
Re: Pipe Organ
Greets!
Hmm, since a full on pipe organ has by far the most fundamentals, ergo harmonics, overtones, etc., my question wasn't how low the drivers can go, but when limited to the same LF response as the 'Golden Bowls' CD, can they do the rest of the pipe organ CD's signal with the same sense of 'real' or must it be even more BW limited to keep it from falling apart on such a complex signal? Indeed, can it do so on any segment of its BW?
Regardless, you're right, trying to extract much LF out of any truly hi-def driver not specifically designed to reproduce an ultra-wide BW is to degrade its performance, defeating the point of all that craftsmanship IMO.
GM
talawalla said:
Greets!
Hmm, since a full on pipe organ has by far the most fundamentals, ergo harmonics, overtones, etc., my question wasn't how low the drivers can go, but when limited to the same LF response as the 'Golden Bowls' CD, can they do the rest of the pipe organ CD's signal with the same sense of 'real' or must it be even more BW limited to keep it from falling apart on such a complex signal? Indeed, can it do so on any segment of its BW?
Regardless, you're right, trying to extract much LF out of any truly hi-def driver not specifically designed to reproduce an ultra-wide BW is to degrade its performance, defeating the point of all that craftsmanship IMO.
GM
I've got the D5nf in the BVR enclosure... with Saint-Saens organ symphony, you certainly get the sense "real", sans the last couple octaves and SPL levels. Having been fortunate to be in some wonderful cathedrals all around Europe and having listened to the superb pipe organs in person, nothing will create that sense of real.... at least not at that level. This is one case where being there makes all the difference.
I must admit that the Feastrex drivers (and I've got the absolute cheapest of them all) provide an unmistakable sense of real to well recorded music (bandwidth limitations noted). You can easily discern what was recorded live and parts that were dubbed in later. You get the sense of the recording venue, musician/instrument placement, depth, distance, etc. With bad recordings, it's actually annoying to some degree, but with superb recordings, you simply forget (all) the equipment and become involved in the musical performance.
Yes, I like my "bottom of the line" drivers. If I ever get out your way Joe, you'll get a call... and I'll bring a nice bottle of wine!
Regards, KM
I must admit that the Feastrex drivers (and I've got the absolute cheapest of them all) provide an unmistakable sense of real to well recorded music (bandwidth limitations noted). You can easily discern what was recorded live and parts that were dubbed in later. You get the sense of the recording venue, musician/instrument placement, depth, distance, etc. With bad recordings, it's actually annoying to some degree, but with superb recordings, you simply forget (all) the equipment and become involved in the musical performance.
Yes, I like my "bottom of the line" drivers. If I ever get out your way Joe, you'll get a call... and I'll bring a nice bottle of wine!
Regards, KM
Even when the very bottom is not fully presented, the D5e Type II absolutely will not fall apart on any material. I've yet to hear them break up in any fashion. Rock solid. So yes, even on tremendously complex material, what is there is crystal clear. On most recordings the bass is all you could ever ask for. Occasionally it is a little shy.
talawalla said:
And, I think that "little shyness" in the deepest bass can be reduced even further with the right enclosure. The funky box is amazing but there is still room for improvement, according to the buzz from Yamanashi.
-- Chris
FWIW, I heard that the MaxxHorn enclosures with Feastrex D5 Moster Alnico drivers produced "absolutely incredible" bass when they made their debut at CES in Las Vegas in January. At the time, they were playing Bach's Toccata and Fugue in D Minor, and the speakers shook the room. I wish I could have been there to hear that.
It would also be very interesting to hear MaxxHorns with the D5e drivers in them, too. I heard the previous model at RMAF with D5nf drivers, and I thought they sounded great. The new ones they had at CES were designed specifically for the D5 Monster Alnico drivers.
Mike
It would also be very interesting to hear MaxxHorns with the D5e drivers in them, too. I heard the previous model at RMAF with D5nf drivers, and I thought they sounded great. The new ones they had at CES were designed specifically for the D5 Monster Alnico drivers.
Mike
Japanese urushi lacquer craftsman takes to Feastrex
Recently a highly respected lacquerware craftsman in Kyoto (who is also highly respected among Japanese audiophiles as a veteran designer and builder of loudspeaker enclosures) has taken a keen interest in Feastrex fullrange drivers and has begun developing a backloaded horn enclosure for one model of driver that he hopes to be able to commercialize. (Presumably if he succeeds, enclosures for other models will follow.) It is my understanding that this gentleman has been predominantly influenced in his approach to horn design by Tetsuo Nakagoka. (However, he does not put Nagaoka up on a pedestal, and he recognizes -- as did Nagaoka himself -- that some Nagaoka designs are duds.) Anyone who has studied Tetsuo Nagaoka in any depth knows that he developed his own theory of horn design; I am not well enough versed in horns to state how his approach may be similar to or differ from the approaches of others. And of course technically speaking most of his "horns" were not true horns as they were either constant-width or a series of connected straight pipes. But regardless of what they are technically, it is sure that some of his designs were simply outstanding performers, and continue to have a strong following both in Japan and overseas years after his death.
Here are some thoughts on backloaded horn design passed on by this gentleman (everything between the two rows of asterisks are mostly his comments, although I have done a bit of editing):
******************************
Nagaoka's formulae for horn design are well known and highly practical -- at least with the drivers that he was working with at the time -- but they are not always entirely useful for some of the more recent drivers, and I have modified his formulae somewhat. However, with the Feastrex D5nf I strongly suspect that even my modified Nagaoka formulae will be of limited use. I am definitely getting into entirely new territory (new for me, that is) with this driver.
Fortunately, I closely followed Nagaoka from his earliest days, and I read every article he wrote in the order that he wrote them, so I have a good idea of how his own thinking developed over time. I know what I need to do . . . "cut, try, listen, and measure!" If I do that a few times the knowledge gained from each sample should take me to where I want to go. Perhaps that will help me to improve the formula to take into account the somewhat unique behavior of Feastrex drivers.
First cavity (back cavity) volume
The volume of the first cavity will determine the high-end cutoff frequency of the horn. If we think of the backloaded horn enclosure as a mechanical two-way loudspeaker (i.e., with the direct sound coming off the front of the driver and the lower frequencies reinforced by the horn), this first cavity corresponds to the crossover network. The larger the first cavity volume, the lower the crossover. That's Nagaoka's approach.
However, I think in the case of the D5nf, it might be appropriate to have a first cavity volume twice as large as that called for by Nagaoka. I think this driver has the power to drive that without difficulty. Certainly it seems to me that will be the case with the more powerful Feastrex drivers, but initially at least I shall take this approach with the D5nf as well. We shall see what happens.
Throat constriction ratio
Nagaoka calculated the throat constriction ratio from the diaphragm surface area and the Qts. For example, with a Qts=0.4 driver he would have the throat constriction be 50% of the diaphragm area. When Qts is 0.2, it becomes 100%, but I think he had the behavior of contemporaneous Fostex drivers in mind when he came up with the above formula.
I think that after the D5nf has had some time to run in, it might do well with a throat constriction of around 100%. At least I plan to start with exactly 100% and see what happens.
Horn mouth area, horn length, shape, and other considerations
These factors depend to a large extent on the capabilities of the driver. The D5nf has considerable drive power so I think the horn mouth could be made quite large, but if it is made too large the enclosure itself becomes unwieldy, and it becomes more easily subject to horn colorations.
Only about 1% of Nagaoka's designs have survived with continued popularity. He was continually striving to push the limits of performance. The good designs continue to be built exactly to the original dimensions he specified, without variance, for the appropriate units, by his most ardent followers.
When Fostex introduces a limited edition driver, they usually sell their entire production in one or two days. That is because Nagaoka's most ardent followers line up to buy them. However, a 13cm driver limited edition driver that Fostex introduced late last year is still not sold out after four months. That's because Nagaoka never designed a winning enclosure for this size and type of driver.
I learned a lot by building quite a few Nagaoka duds over the years. Based on my past experience, I plan to have the horn opening in my first trial enclosure be about three times the area of the cone.
A horn length of 2.5 meters is best. With that length of horn you can, in theory, have your fullrange single driver backload horn cover just about the entire orchestra. Obviously you are not going to get the bottom of a pipe organ with that . . .
Some people say a horn length of 2 meters is best but I think that is true only for people who listen exclusively to jazz music.
If you go longer than 2.5 meters, you start to run into problems with the time delay of the sound coming off the back of the driver.
I really like the sound of a well-made Nagaoka type horn, even if it is a series of connected straight pipes. This approach has its detractors, to be sure, and I'm not defending the sound of badly made examples. But the good ones I never tire of listening to.
Many other factors come into play in determining the behavior and sound of the loudspeaker, including the shape of the first cavity, the choice of material used in the enclosure, the thickness of the material (which may vary in different parts of the enclosure) the type of finish applied, etc. A lot of effort is involved in getting all these just right. I only hope my efforts can do full justice to these wonderful units. I have no illusions of being able to get everything just right on my first try. It may take many tries before I can come up with something that really satisfies -- but I am highly motivated by these drivers.
Results of the initial trial enclosure built on the above concepts:
* Fairly happy with the sound of the bass -- it produced audible bass down to 30Hz, although it was certainly not flat.
* It sounds like it is "trying very hard." At high volumes you can see the cone stroking and I am sure that is contributing to distortion of the higher frequencies. More horn loading is needed. I must constrict the throat more. 100% of the cone area is too large a throat diameter. On the other hand, I think I can open up the mouth of the horn more. Another problem is that probably by trying to make the horn as straight (i.e., with a few bends) as possible, I think I have actually exacerbated the resonances that cause comb effects. It has a pronounced "horny" sound and the flute, for example, is not much fun to listen to. Part of remedying this will be to enlarge the size of the horn mouth. So I'll adopt the exponential horn as my underlying model rather than a conical horn.
The first cavity was mostly a success, although it was a bit too small. This caused more of the mid and high frequencies to come through the horn. The resulting overall sound character is actually extremely pleasant to listen to with certain types of music. I enjoy it a lot with jazz. But it is not very good for classical music, and since I want more well-balanced loudspeaker for all-around listening, for my next trial I shall increase the size of the first cavity.
Anyway, this first trial was a good learning experience and it should be fun to see how things go with my second effort, which I hope to get to ASAP.
******************************
Here are some pics of one of the above writer's previous creations, based on the Fostex FE108E-Sigma driver and made entirely from spruce planks and finished with urushi lacquer (please note that I have no idea whether his current concept speaker using the Feastrex D5nf bears a similarity to this or is significantly differerent):
By the way, Feastrex's Mr. Teramoto has recently experimented with urushi on his phase plugs and has been extremely pleased with the results. He says he likes the sound of urushi-coated phase plugs very much. (I still have not had a chance to listen to his samples.)
-- Chris
Recently a highly respected lacquerware craftsman in Kyoto (who is also highly respected among Japanese audiophiles as a veteran designer and builder of loudspeaker enclosures) has taken a keen interest in Feastrex fullrange drivers and has begun developing a backloaded horn enclosure for one model of driver that he hopes to be able to commercialize. (Presumably if he succeeds, enclosures for other models will follow.) It is my understanding that this gentleman has been predominantly influenced in his approach to horn design by Tetsuo Nakagoka. (However, he does not put Nagaoka up on a pedestal, and he recognizes -- as did Nagaoka himself -- that some Nagaoka designs are duds.) Anyone who has studied Tetsuo Nagaoka in any depth knows that he developed his own theory of horn design; I am not well enough versed in horns to state how his approach may be similar to or differ from the approaches of others. And of course technically speaking most of his "horns" were not true horns as they were either constant-width or a series of connected straight pipes. But regardless of what they are technically, it is sure that some of his designs were simply outstanding performers, and continue to have a strong following both in Japan and overseas years after his death.
Here are some thoughts on backloaded horn design passed on by this gentleman (everything between the two rows of asterisks are mostly his comments, although I have done a bit of editing):
******************************
Nagaoka's formulae for horn design are well known and highly practical -- at least with the drivers that he was working with at the time -- but they are not always entirely useful for some of the more recent drivers, and I have modified his formulae somewhat. However, with the Feastrex D5nf I strongly suspect that even my modified Nagaoka formulae will be of limited use. I am definitely getting into entirely new territory (new for me, that is) with this driver.
Fortunately, I closely followed Nagaoka from his earliest days, and I read every article he wrote in the order that he wrote them, so I have a good idea of how his own thinking developed over time. I know what I need to do . . . "cut, try, listen, and measure!" If I do that a few times the knowledge gained from each sample should take me to where I want to go. Perhaps that will help me to improve the formula to take into account the somewhat unique behavior of Feastrex drivers.
First cavity (back cavity) volume
The volume of the first cavity will determine the high-end cutoff frequency of the horn. If we think of the backloaded horn enclosure as a mechanical two-way loudspeaker (i.e., with the direct sound coming off the front of the driver and the lower frequencies reinforced by the horn), this first cavity corresponds to the crossover network. The larger the first cavity volume, the lower the crossover. That's Nagaoka's approach.
However, I think in the case of the D5nf, it might be appropriate to have a first cavity volume twice as large as that called for by Nagaoka. I think this driver has the power to drive that without difficulty. Certainly it seems to me that will be the case with the more powerful Feastrex drivers, but initially at least I shall take this approach with the D5nf as well. We shall see what happens.
Throat constriction ratio
Nagaoka calculated the throat constriction ratio from the diaphragm surface area and the Qts. For example, with a Qts=0.4 driver he would have the throat constriction be 50% of the diaphragm area. When Qts is 0.2, it becomes 100%, but I think he had the behavior of contemporaneous Fostex drivers in mind when he came up with the above formula.
I think that after the D5nf has had some time to run in, it might do well with a throat constriction of around 100%. At least I plan to start with exactly 100% and see what happens.
Horn mouth area, horn length, shape, and other considerations
These factors depend to a large extent on the capabilities of the driver. The D5nf has considerable drive power so I think the horn mouth could be made quite large, but if it is made too large the enclosure itself becomes unwieldy, and it becomes more easily subject to horn colorations.
Only about 1% of Nagaoka's designs have survived with continued popularity. He was continually striving to push the limits of performance. The good designs continue to be built exactly to the original dimensions he specified, without variance, for the appropriate units, by his most ardent followers.
When Fostex introduces a limited edition driver, they usually sell their entire production in one or two days. That is because Nagaoka's most ardent followers line up to buy them. However, a 13cm driver limited edition driver that Fostex introduced late last year is still not sold out after four months. That's because Nagaoka never designed a winning enclosure for this size and type of driver.
I learned a lot by building quite a few Nagaoka duds over the years. Based on my past experience, I plan to have the horn opening in my first trial enclosure be about three times the area of the cone.
A horn length of 2.5 meters is best. With that length of horn you can, in theory, have your fullrange single driver backload horn cover just about the entire orchestra. Obviously you are not going to get the bottom of a pipe organ with that . . .
Some people say a horn length of 2 meters is best but I think that is true only for people who listen exclusively to jazz music.
If you go longer than 2.5 meters, you start to run into problems with the time delay of the sound coming off the back of the driver.
I really like the sound of a well-made Nagaoka type horn, even if it is a series of connected straight pipes. This approach has its detractors, to be sure, and I'm not defending the sound of badly made examples. But the good ones I never tire of listening to.
Many other factors come into play in determining the behavior and sound of the loudspeaker, including the shape of the first cavity, the choice of material used in the enclosure, the thickness of the material (which may vary in different parts of the enclosure) the type of finish applied, etc. A lot of effort is involved in getting all these just right. I only hope my efforts can do full justice to these wonderful units. I have no illusions of being able to get everything just right on my first try. It may take many tries before I can come up with something that really satisfies -- but I am highly motivated by these drivers.
Results of the initial trial enclosure built on the above concepts:
* Fairly happy with the sound of the bass -- it produced audible bass down to 30Hz, although it was certainly not flat.
* It sounds like it is "trying very hard." At high volumes you can see the cone stroking and I am sure that is contributing to distortion of the higher frequencies. More horn loading is needed. I must constrict the throat more. 100% of the cone area is too large a throat diameter. On the other hand, I think I can open up the mouth of the horn more. Another problem is that probably by trying to make the horn as straight (i.e., with a few bends) as possible, I think I have actually exacerbated the resonances that cause comb effects. It has a pronounced "horny" sound and the flute, for example, is not much fun to listen to. Part of remedying this will be to enlarge the size of the horn mouth. So I'll adopt the exponential horn as my underlying model rather than a conical horn.
The first cavity was mostly a success, although it was a bit too small. This caused more of the mid and high frequencies to come through the horn. The resulting overall sound character is actually extremely pleasant to listen to with certain types of music. I enjoy it a lot with jazz. But it is not very good for classical music, and since I want more well-balanced loudspeaker for all-around listening, for my next trial I shall increase the size of the first cavity.
Anyway, this first trial was a good learning experience and it should be fun to see how things go with my second effort, which I hope to get to ASAP.
******************************
Here are some pics of one of the above writer's previous creations, based on the Fostex FE108E-Sigma driver and made entirely from spruce planks and finished with urushi lacquer (please note that I have no idea whether his current concept speaker using the Feastrex D5nf bears a similarity to this or is significantly differerent):
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
By the way, Feastrex's Mr. Teramoto has recently experimented with urushi on his phase plugs and has been extremely pleased with the results. He says he likes the sound of urushi-coated phase plugs very much. (I still have not had a chance to listen to his samples.)
-- Chris
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The reddish color phase plug is the one painted with urushi lacquer. That is the natural color of the urushi lacquer -- there is no coloring added. Of course various other colors are possible. Here are other examples of work by the same craftsman:
http://www.konnanodo.com/shop/tanbashikki/
An externally hosted image should be here but it was not working when we last tested it.
-- Chris
Chris - love your stories and keeping this thread alive with the varied applications involving the feastrex drivers. Sadly can only dream about these in my room but maybe someday. Also love the portal you provide into the Japanese audio scene with audio values that I much admire. Keep posting .... I check back weekly to read your latest installment feeling like an audio voyeur at this point but your time and enthusiasm is valued and much enjoyed all the way to southwest Vancouver Island!
David
David
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