Konnichiwa,
This whole story was blogged out in a little more posts detail and all over at the DIY-HiFisupply Forum. But I figured it may interrest some of you.
A good while ago Brian Cherry started the development of a moderatly small, high tech (Neodymium Magnet among other things) full range driver called for some inscrutable reason NeoFone. I had some minor peripheral involvement with this and hence have know about this for a while. While I'm not allowed to say much, the designer behind this driver is one of greats for "small drivers" and has quite an impressive trackrecord (but wishes to remain incognito on this).
In the end got a pair of the final drivers to make up some speakers for the bedroom which where meant to be a little prettier than the current ugly but good sounding ones with C37 lacquered japanese 6.5" Alnic Fullrange Drivers. Quick listening tests in open air confirmed that the driver had good potential.
Brian had also picked up a good deal of surplus Foster Leaf tweeters with "lens" attachment (these are the same as found on older Legacy Speakers such as the Whisper or Focus 20/20) so I got a Pair of these too to use as super tweeter. I had previously worked out with Brian that these work very well in that role with the NeoFones when used straight with just a 0.68uF series capacitor, nothing else.
Due to time commitments at work and with other projects the Speaker simply stalled untill last week when I came in the local Woolworth across something that looked just like a solid wood Minimonitor Speaker enclosure to me. It was actually a wooden breadbox!
It was pretty dead to a knuckle rap and what resonance was there dissipated rapidly, giving a pretty dry overall sound, except for mthe bottom, which is fairly thin. Anyway, I made off home with two of them and a pillow, to be torn apart to yield some polyerster batting.
Afterwards I popped in (pausing at home only to measure the inside dimensions of the breadbox) to the local B&Q Builder/DIY Merchant. There I got me a pair of 18mm (3/4") MDF Baffles cut to be glued in against the bottom to reinforce it. I had decided to use the slightly inset bottom as the "Front" of the speaker. I figured the drivers should beam enough at the frequencies these edges are obstacles that edge diffraction would not be an issue and it looked overall better to me.
I also picked up some junction pieces and short pipe pieces in 40mm inner diameter up from the plumbing section. The advantage is that you can easily extend your port and even add ellbow joins to extend it an angle using this stuff and it's cheap.
As I had quite a bit of offcut from the smallest sheet MDF I could buy I also got a pair of shelf braces cut that left around 38mm (1.5") between the rear panel and the shelf brace (plus some other pieces for another project).
I glued the baffle in using "Evostic Resin W" Weatherproof wood glue, I also used this to glue the back on after putting the shelf brace in according to the golden ratio. Golden ratio bracing works by dividing any dimension to be braced by 2.618 and placing the brace at the indicated distance. Thus each dimension is subdivided into a 1 & 1.618 long part and any remaining resonaces are spread out.
Serendipitously I also found two suitable 38mm wooden blocks which I adhered to the rear pannel and which in turn reinforce the center of rear panel, which used to be the breadbox lid and connect read and front panel via the shelf brace.
I flew to the Munich HiFi Show after gluing everything, so by the time i came back all glue was bone dry and resulting enclosure turned out quite light, very rigid and with not much resonance remaining and what remained most crucially sounded very dry indicating low energy storage and quick lossy decay.
During the week I was tied up, but yesterdays weather was lending itself to woodworking in the garden, so I got the tools out and cut the various holes using drill & holesaw for the NeoFone Driver and port and a jigsaw for the irregular cutout needed for the Foster Ribbon Tweeter.
In order to mess up the finish on the front panel with the jigsaw's base I used a bunch of waste A4 paper (unprinted side down) between it and the wood.
As my shelf brace was placed according to the golden ratio and left only a moderately deep slot at the back, in effect subdividing the enclosure. I cut the holes with the port and Foster ribbon in the smaller upper chamber with the port on the back and the NeoFone in the larger lower chamber on the front (of course).
I used a some pillock, ahhm, pillow stuffing (around a quarter pillow) stuffing in the lower chamber, the upper is empty. I used bare 1mm silver wire for connections, together with these chinese WBT copy binding posts ("charming music connectors"). The "hot" connector was sleeved in some 5mm diameter glass fibre sleeving to prevent the wires from shorting.
The Foster Ribbon is connected using thinner enameled silver (I find myself using a lot of silver these days, I have it around and at hand, copper I'd have to dig out!)....
As my big drill just broke (when I was finishing cutting the second NeoFone holes with a big hole saw) I did not do my usual trick of drilling out the center of the binding post and running bare wire through the binding posts so that the binding posts are effectively bypassed.
As I used piping from the plumbing section I had a 40mm Port 80mm as the minimum, with the option to extend it by plugging in another piece (and another, untill I get bored). I ended up with a similar tuning as Brian by leaving just the 80mm long piece.
According to WinIsd using the T/S Parameters from Brians Site this gives a tuning at 54Hz with -3db @ 50Hz. My own Spreadsheets accounting for room positioning somewhat place the -6db point at 40Hz and subjectively this seems born out.
To roll in the Foster Ribbon I used a compound capacitor of 0.69uF. I did not seem to have any 0.68uF around so I looked into my junk, ahhhm, project box. I found a pair of 0.47uF Solen MKP (I know, I pooh pooh them at any convenient occasion, hence they where in the junk box not in gear - but I figured okay for supertweeter duties) and some Multicap PPFX 0.22uF, making 0.69uF.
I could have dug around in all the various places I keep components for a single 0.68uF instead, but I figured .69 gotta be more fun than .68, if ya know what I mean....
Well, that was the speakers complete, I dropped them into the big system instead of my normal fieldcoil equipped Transparence open baffles with Visaton TL16H Supertweeters and a dual 12" Subwoofer.
With the speakers having the 54Hz tuning and being literally used as Bookshelf speakers (see photo) close to rear walls the bass is proportionate, if missing the lowest octave, on a lot of music it makes sense. I listened so far mostly to rock & pop and the speakers sound well balanced, with a bass that next to open baffles is a little boxy and lumpy, but quite tight and precise. Also, the amount and depth of the bass is surprising for a miniature, at least placed as I did.
The midrange and treble is clean and in proportion, quite well detailed and brilliant, untill you really crank the system up and things fall apart. Again, imaging is pretty good and stays stable up to high SPL's.
Classical is fine with a great and delicate string tone and loads of air only really big stuff leaves you wishing for more and perhaps for a subwoofer. Notably, the strings have a silkiness and smoothness few affordable fullrange drivers manage. The Woodwinds too sound great with a natural tone, the brass section blareds as it should.
I'm driving them right now with my triode wired (good for around 30W) Shanling SP-80 Monoblocks which also had their solid state preamp section removed, a Music First Audio Passive Magnetic Preamp and a CD Player I'm not allowed to say much about yet (Vinyl is as before).
In my reviewers days I used to refuse any offers of "MiniMonitors" with a simple "It's a minimonitor and thus disqualified from High Fidelity" and sadly the NeoFone does not change that. It makes for a really good small speaker though and maybe with a subwoofer and very low frequencies cut off it can manage good fidelity in small rooms with the full range of music.
So, it's a "MiniMonitor" that is really good for the genre but does not break out of it's limits. That said, if you want a small box and have a small room and at least 20 - 30W amplifier power available this little box can be good fun and it is fairly inexpensive and easy to make.
I have no other small monitors here for direct comparison, so I'll not indulge in claiming it outperforms this or that, it simply is a good speaker and good enough that I feel no immediate inclination to take it out of the big rig.
So, if you like minimotors and need or want another pair, get a pair and make a "Breadbox". If you prefer Altec Voice Of the Theater and prefer 45 SE Amplifiers then look elsewhere, but just like in my case you might find a use for them in a second system.
In balance, the NeoFone is well recommended, within the limits of it's format, I think the DynaFone (Brians Subwoofer) as woofer, NeoFone as Midrange and the Foster Ribbon build as a full three way speaker into a nice big floorstanding enclosure would make the best out of the NeoFone and let it be really good at what it does well (midrange and lower treble) and help add scale and dynamics with a full range bass. But that would be a very different speaker to what I build.
Sayonara
This whole story was blogged out in a little more posts detail and all over at the DIY-HiFisupply Forum. But I figured it may interrest some of you.
A good while ago Brian Cherry started the development of a moderatly small, high tech (Neodymium Magnet among other things) full range driver called for some inscrutable reason NeoFone. I had some minor peripheral involvement with this and hence have know about this for a while. While I'm not allowed to say much, the designer behind this driver is one of greats for "small drivers" and has quite an impressive trackrecord (but wishes to remain incognito on this).
An externally hosted image should be here but it was not working when we last tested it.
In the end got a pair of the final drivers to make up some speakers for the bedroom which where meant to be a little prettier than the current ugly but good sounding ones with C37 lacquered japanese 6.5" Alnic Fullrange Drivers. Quick listening tests in open air confirmed that the driver had good potential.
Brian had also picked up a good deal of surplus Foster Leaf tweeters with "lens" attachment (these are the same as found on older Legacy Speakers such as the Whisper or Focus 20/20) so I got a Pair of these too to use as super tweeter. I had previously worked out with Brian that these work very well in that role with the NeoFones when used straight with just a 0.68uF series capacitor, nothing else.
Due to time commitments at work and with other projects the Speaker simply stalled untill last week when I came in the local Woolworth across something that looked just like a solid wood Minimonitor Speaker enclosure to me. It was actually a wooden breadbox!
An externally hosted image should be here but it was not working when we last tested it.
It was pretty dead to a knuckle rap and what resonance was there dissipated rapidly, giving a pretty dry overall sound, except for mthe bottom, which is fairly thin. Anyway, I made off home with two of them and a pillow, to be torn apart to yield some polyerster batting.
Afterwards I popped in (pausing at home only to measure the inside dimensions of the breadbox) to the local B&Q Builder/DIY Merchant. There I got me a pair of 18mm (3/4") MDF Baffles cut to be glued in against the bottom to reinforce it. I had decided to use the slightly inset bottom as the "Front" of the speaker. I figured the drivers should beam enough at the frequencies these edges are obstacles that edge diffraction would not be an issue and it looked overall better to me.
I also picked up some junction pieces and short pipe pieces in 40mm inner diameter up from the plumbing section. The advantage is that you can easily extend your port and even add ellbow joins to extend it an angle using this stuff and it's cheap.
As I had quite a bit of offcut from the smallest sheet MDF I could buy I also got a pair of shelf braces cut that left around 38mm (1.5") between the rear panel and the shelf brace (plus some other pieces for another project).
I glued the baffle in using "Evostic Resin W" Weatherproof wood glue, I also used this to glue the back on after putting the shelf brace in according to the golden ratio. Golden ratio bracing works by dividing any dimension to be braced by 2.618 and placing the brace at the indicated distance. Thus each dimension is subdivided into a 1 & 1.618 long part and any remaining resonaces are spread out.
Serendipitously I also found two suitable 38mm wooden blocks which I adhered to the rear pannel and which in turn reinforce the center of rear panel, which used to be the breadbox lid and connect read and front panel via the shelf brace.
I flew to the Munich HiFi Show after gluing everything, so by the time i came back all glue was bone dry and resulting enclosure turned out quite light, very rigid and with not much resonance remaining and what remained most crucially sounded very dry indicating low energy storage and quick lossy decay.
During the week I was tied up, but yesterdays weather was lending itself to woodworking in the garden, so I got the tools out and cut the various holes using drill & holesaw for the NeoFone Driver and port and a jigsaw for the irregular cutout needed for the Foster Ribbon Tweeter.
In order to mess up the finish on the front panel with the jigsaw's base I used a bunch of waste A4 paper (unprinted side down) between it and the wood.
As my shelf brace was placed according to the golden ratio and left only a moderately deep slot at the back, in effect subdividing the enclosure. I cut the holes with the port and Foster ribbon in the smaller upper chamber with the port on the back and the NeoFone in the larger lower chamber on the front (of course).
I used a some pillock, ahhm, pillow stuffing (around a quarter pillow) stuffing in the lower chamber, the upper is empty. I used bare 1mm silver wire for connections, together with these chinese WBT copy binding posts ("charming music connectors"). The "hot" connector was sleeved in some 5mm diameter glass fibre sleeving to prevent the wires from shorting.
The Foster Ribbon is connected using thinner enameled silver (I find myself using a lot of silver these days, I have it around and at hand, copper I'd have to dig out!)....
As my big drill just broke (when I was finishing cutting the second NeoFone holes with a big hole saw) I did not do my usual trick of drilling out the center of the binding post and running bare wire through the binding posts so that the binding posts are effectively bypassed.
As I used piping from the plumbing section I had a 40mm Port 80mm as the minimum, with the option to extend it by plugging in another piece (and another, untill I get bored). I ended up with a similar tuning as Brian by leaving just the 80mm long piece.
According to WinIsd using the T/S Parameters from Brians Site this gives a tuning at 54Hz with -3db @ 50Hz. My own Spreadsheets accounting for room positioning somewhat place the -6db point at 40Hz and subjectively this seems born out.
To roll in the Foster Ribbon I used a compound capacitor of 0.69uF. I did not seem to have any 0.68uF around so I looked into my junk, ahhhm, project box. I found a pair of 0.47uF Solen MKP (I know, I pooh pooh them at any convenient occasion, hence they where in the junk box not in gear - but I figured okay for supertweeter duties) and some Multicap PPFX 0.22uF, making 0.69uF.
I could have dug around in all the various places I keep components for a single 0.68uF instead, but I figured .69 gotta be more fun than .68, if ya know what I mean....
Well, that was the speakers complete, I dropped them into the big system instead of my normal fieldcoil equipped Transparence open baffles with Visaton TL16H Supertweeters and a dual 12" Subwoofer.
An externally hosted image should be here but it was not working when we last tested it.
With the speakers having the 54Hz tuning and being literally used as Bookshelf speakers (see photo) close to rear walls the bass is proportionate, if missing the lowest octave, on a lot of music it makes sense. I listened so far mostly to rock & pop and the speakers sound well balanced, with a bass that next to open baffles is a little boxy and lumpy, but quite tight and precise. Also, the amount and depth of the bass is surprising for a miniature, at least placed as I did.
The midrange and treble is clean and in proportion, quite well detailed and brilliant, untill you really crank the system up and things fall apart. Again, imaging is pretty good and stays stable up to high SPL's.
Classical is fine with a great and delicate string tone and loads of air only really big stuff leaves you wishing for more and perhaps for a subwoofer. Notably, the strings have a silkiness and smoothness few affordable fullrange drivers manage. The Woodwinds too sound great with a natural tone, the brass section blareds as it should.
I'm driving them right now with my triode wired (good for around 30W) Shanling SP-80 Monoblocks which also had their solid state preamp section removed, a Music First Audio Passive Magnetic Preamp and a CD Player I'm not allowed to say much about yet (Vinyl is as before).
In my reviewers days I used to refuse any offers of "MiniMonitors" with a simple "It's a minimonitor and thus disqualified from High Fidelity" and sadly the NeoFone does not change that. It makes for a really good small speaker though and maybe with a subwoofer and very low frequencies cut off it can manage good fidelity in small rooms with the full range of music.
So, it's a "MiniMonitor" that is really good for the genre but does not break out of it's limits. That said, if you want a small box and have a small room and at least 20 - 30W amplifier power available this little box can be good fun and it is fairly inexpensive and easy to make.
I have no other small monitors here for direct comparison, so I'll not indulge in claiming it outperforms this or that, it simply is a good speaker and good enough that I feel no immediate inclination to take it out of the big rig.
So, if you like minimotors and need or want another pair, get a pair and make a "Breadbox". If you prefer Altec Voice Of the Theater and prefer 45 SE Amplifiers then look elsewhere, but just like in my case you might find a use for them in a second system.
In balance, the NeoFone is well recommended, within the limits of it's format, I think the DynaFone (Brians Subwoofer) as woofer, NeoFone as Midrange and the Foster Ribbon build as a full three way speaker into a nice big floorstanding enclosure would make the best out of the NeoFone and let it be really good at what it does well (midrange and lower treble) and help add scale and dynamics with a full range bass. But that would be a very different speaker to what I build.
Sayonara
I recently purchased a set of these Neo-Fones on e-bay, and while I haven't planted them in the BIB's I've built, they sound quite nice just sitting on my desk tilted back. The gentleman I bought them from had this to say :
The Neo-Fone was one of the few drivers that I didn't run distortion curves on. While I did run a frequency response measurement, it was not saved since I used it only to notch-out minor resonances with the Behringer EQ. The driver, as I recall, was much better damped than the Seas Magnesium Excel drivers we have (W15's) and vastly superior to the aluminum L15's, sonically. I didn't compare the frequency response measurement with the online version, but I remember it being fairly smooth. The Neo-Fone cone did not impart too much of its sonic character on music, unlike the strong sonic character imparted by many metal or paper cones.
The Neo-Fone was one of the few drivers that I didn't run distortion curves on. While I did run a frequency response measurement, it was not saved since I used it only to notch-out minor resonances with the Behringer EQ. The driver, as I recall, was much better damped than the Seas Magnesium Excel drivers we have (W15's) and vastly superior to the aluminum L15's, sonically. I didn't compare the frequency response measurement with the online version, but I remember it being fairly smooth. The Neo-Fone cone did not impart too much of its sonic character on music, unlike the strong sonic character imparted by many metal or paper cones.
Hi KYW/T,
That's a sweet bread box there.
BTW, for those intrested, here's dims for a Neofone BIB enclosure done by Scottmoose:
"As per a request for the neophone, here's one.
Line length 128in.
Zdriver 25.75in
Sm (or Sl if you are so inclined) 55in^2."
Could be a slender small footprint but tallish cabs for corner placement/loading.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=66173&perpage=10&pagenumber=1
http://www.zillaspeak.com/bib.asp
That's a sweet bread box there.
BTW, for those intrested, here's dims for a Neofone BIB enclosure done by Scottmoose:
"As per a request for the neophone, here's one.
Line length 128in.
Zdriver 25.75in
Sm (or Sl if you are so inclined) 55in^2."
Could be a slender small footprint but tallish cabs for corner placement/loading.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=66173&perpage=10&pagenumber=1
http://www.zillaspeak.com/bib.asp
Babelfish also sucks but here is that translation for those inquisitive minds that only understand English: "I heard, this way lead to the ocean of death, and turned around half-way. Since that time detours stretch, desert and bent before me"BTW, nice job on the minimonitors. The serendipitous nature of it adds to it's value, IMO.Kuei Yang Wang said:
KYW,
Great review. Thanks!
The breadbox is in the true spirit of DIY. Very cool.
I've been curious as to how the NeoFones sound since I first saw them on Brian's site. Seems like a decent driver for a good-sounding fun project.
The obvious question is how do they compare to the CSS FR125/WR125 or the Jordan drivers?
I'm sure we'll find out soon as more folks get a chance to compare.
Best,
KT
Great review. Thanks!
The breadbox is in the true spirit of DIY. Very cool.
I've been curious as to how the NeoFones sound since I first saw them on Brian's site. Seems like a decent driver for a good-sounding fun project.
The obvious question is how do they compare to the CSS FR125/WR125 or the Jordan drivers?
I'm sure we'll find out soon as more folks get a chance to compare.
Best,
KT
Konnichiwa,
I would prefer:
"I heard, this way lead to the ocean of death, and turned back half-way. Since then detours stretch in front of me, deserted and serpentine" It still does not quite have the ring though.
It may be worth noting the context of this quote. In the (sci-fi) novel this is from (A million years before the end of the world) a group of scientists/engineers seem all onto great discoveries, but things keep happening (all sorts of such) that throw them off track. It turns out that the "hoemeostatic worldfabric" prevents them from making inventions that at some point in the far future may irreversably change or destry it.
In line with the common theme of russian SF we mainly experience the way the protagonists cope with this "out of this world" situation. One commits suicide, others give up their work, another collects the bit's of their work they have finished for safekeeping etc....
The line I quote belongs to someone who has given up, because of wife, child and all that. I keep it as memento mori and to remind myself of the times I have given up, because the pressure was too much. "Since then detours stretch in front of me, deserted and serpentine"
Thanks for the flowers otherwise.
I have got some exposure to the Jordan JX92. I cannot directly compare, but on memory alone the Jordans played less low and had a more constrained dynamic range.
Sayonara
westend said:
I would prefer:
"I heard, this way lead to the ocean of death, and turned back half-way. Since then detours stretch in front of me, deserted and serpentine" It still does not quite have the ring though.
It may be worth noting the context of this quote. In the (sci-fi) novel this is from (A million years before the end of the world) a group of scientists/engineers seem all onto great discoveries, but things keep happening (all sorts of such) that throw them off track. It turns out that the "hoemeostatic worldfabric" prevents them from making inventions that at some point in the far future may irreversably change or destry it.
In line with the common theme of russian SF we mainly experience the way the protagonists cope with this "out of this world" situation. One commits suicide, others give up their work, another collects the bit's of their work they have finished for safekeeping etc....
The line I quote belongs to someone who has given up, because of wife, child and all that. I keep it as memento mori and to remind myself of the times I have given up, because the pressure was too much. "Since then detours stretch in front of me, deserted and serpentine"
Thanks for the flowers otherwise.
KT said:
I have got some exposure to the Jordan JX92. I cannot directly compare, but on memory alone the Jordans played less low and had a more constrained dynamic range.
Sayonara
Konnichiwa
Some more or less final sounds on the NeoFone breadboxes, now that they have been put into the main system in a more optimised position (I need a pair of somewhat more "ordinary" speakers for some commercial development work)....
All these are just for the Satelites on their own, no Subwoofers connected (yet).
Yesterday I was playing some Dire Straights at elevated levels. I actually had the music earlier at very unsociable levels, that was definitly more than the Amp/Speaker combo was happy with, but untill I put a bigger amp into the system I will not know if the Amplifiers (around 30W max) or speakers are at fault, I suspect the amplifiers though.
What can I say, the soundscape is great and nearly as deep as I'm used to with open baffles and if you discount the fact that anything below 40Hz is AWOL (not as limiting musically as it may appear) the speakers have both rather above average low and high level dynamics.
The NeoFone is the first small fullranger (6.5" or smaller) in my system that makes sense. The various incarnations of the Beauhorn B2 with Fostex FE168 and 5" ATD Fullrange, Bert Doppenberg TQWT with dual FE103 and so on, all the other smaller fullrangers I had where severely challended in the "cojones" department and in terms of maximum loudness, something which one always "excuses" with small fullrangers in favour of their undeniable strength in other areas.
The NeoFone's do not need excuses. It is at least the equal of most good 5" woofers if not 6" woofers in the bass. It is probably the easiest "complete in itself" speaker I can think of readily, all others become 2 or 3 Way and require larger drivers to do the same.
The Supertweeters CAN be dispensed with if you listen straight on axis, I prefer them operating though, there is more "air" with them on.
Sayonara
Some more or less final sounds on the NeoFone breadboxes, now that they have been put into the main system in a more optimised position (I need a pair of somewhat more "ordinary" speakers for some commercial development work)....
All these are just for the Satelites on their own, no Subwoofers connected (yet).
Yesterday I was playing some Dire Straights at elevated levels. I actually had the music earlier at very unsociable levels, that was definitly more than the Amp/Speaker combo was happy with, but untill I put a bigger amp into the system I will not know if the Amplifiers (around 30W max) or speakers are at fault, I suspect the amplifiers though.
What can I say, the soundscape is great and nearly as deep as I'm used to with open baffles and if you discount the fact that anything below 40Hz is AWOL (not as limiting musically as it may appear) the speakers have both rather above average low and high level dynamics.
The NeoFone is the first small fullranger (6.5" or smaller) in my system that makes sense. The various incarnations of the Beauhorn B2 with Fostex FE168 and 5" ATD Fullrange, Bert Doppenberg TQWT with dual FE103 and so on, all the other smaller fullrangers I had where severely challended in the "cojones" department and in terms of maximum loudness, something which one always "excuses" with small fullrangers in favour of their undeniable strength in other areas.
The NeoFone's do not need excuses. It is at least the equal of most good 5" woofers if not 6" woofers in the bass. It is probably the easiest "complete in itself" speaker I can think of readily, all others become 2 or 3 Way and require larger drivers to do the same.
The Supertweeters CAN be dispensed with if you listen straight on axis, I prefer them operating though, there is more "air" with them on.
Sayonara
Konnichiwa,
Best e-mail Brian Cherry directly. I have some stuff that came my way during the development process, but they where not for public consumption.
The published FR BTW is not THAT different from the more detailed factory plots I have seen, so it is quite representative and not excessively smoothed and pen-damped:
Outer frame diameter is around 150mm, cone diameter around 120mm with rated 6.3mm linear excursion peak one way (so 12.6mm or 1/2" peak to peak cone displacement!).
Aluminum Alloy with a special anodising process to prevent the strong breakup modes normally observed.
The Driver was designed by a guy whose name I have been asked not to mention, but who does know his trade and has been doing metal cone speakers for a long time (not full range drivers though). I'm afraid you have to take my word for now....
This driver aparently has a 50 diameter voice coil (from what I can work out), a neodymium magnet where the magnet is inside the voicecoil and a rather nicely solid cast frame.
soongsc said:
Best e-mail Brian Cherry directly. I have some stuff that came my way during the development process, but they where not for public consumption.
The published FR BTW is not THAT different from the more detailed factory plots I have seen, so it is quite representative and not excessively smoothed and pen-damped:
An externally hosted image should be here but it was not working when we last tested it.
Outer frame diameter is around 150mm, cone diameter around 120mm with rated 6.3mm linear excursion peak one way (so 12.6mm or 1/2" peak to peak cone displacement!).
soongsc said:
Aluminum Alloy with a special anodising process to prevent the strong breakup modes normally observed.
The Driver was designed by a guy whose name I have been asked not to mention, but who does know his trade and has been doing metal cone speakers for a long time (not full range drivers though). I'm afraid you have to take my word for now....
This driver aparently has a 50 diameter voice coil (from what I can work out), a neodymium magnet where the magnet is inside the voicecoil and a rather nicely solid cast frame.
Kuei Yang Wang said:Konnichiwa,
Best e-mail Brian Cherry directly. I have some stuff that came my way during the development process, but they where not for public consumption.
The published FR BTW is not THAT different from the more detailed factory plots I have seen, so it is quite representative and not excessively smoothed and pen-damped:
An externally hosted image should be here but it was not working when we last tested it.
Outer frame diameter is around 150mm, cone diameter around 120mm with rated 6.3mm linear excursion peak one way (so 12.6mm or 1/2" peak to peak cone displacement!).
Aluminum Alloy with a special anodising process to prevent the strong breakup modes normally observed.
The Driver was designed by a guy whose name I have been asked not to mention, but who does know his trade and has been doing metal cone speakers for a long time (not full range drivers though). I'm afraid you have to take my word for now....
This driver aparently has a 50 diameter voice coil (from what I can work out), a neodymium magnet where the magnet is inside the voicecoil and a rather nicely solid cast frame.
The dip around 5K and the hump after that looks suspiciously like the JX125 probably caused by the cap. Plus the "anodising" ...
Konnichiwa,
The final shape of the dip is probably at least somewhat down to my own ideas.
The problem is that any such driver if the cone is not allowed to break up will roll off at some point due to the mass rolloff (and/or voice coil inductance).
If you push the breakup out far enough, which I felt was sonically preferable in principle to an earlier breakup in the region where the ear is most sensitive, you get this kind of dip, which in turn is not entierly unlike the BBC Dip and can help the speaker to avoid sounding spitty or too forward when played loud.
Clearly, above 5KHz reasonably well damped cone breakup is used to take the response up further, but at that point the human hearing rapidly looses resolution , so the breakup is not THAT BAD a thing.
Equally, if you have a really large wideband driver it is worth letting it break up softly at a very low frequency, Eckmiller set the cone breakup in his 12" 2-Way coax around 300Hz, with a crossover at 2KHz! The breakup region of the 2" Aluminum Dome however was pushed up to past 8KHz IIRC.
Anyway, I recommended back when to brian to push the notch to around 4-5KHz and to keep it modest. Took quite a few samples to achieve. A "flat" version was aparently also tried (which hence must have gone into breakup at around 3KHz) and which did not sound nice at all.
All in all I think the fairly effortlessness with wich the Drivers handles quite substantial LF input AND the dip make for a speaker that plays subjectively louder than many miniatures (especially with FR Drivers) without strain or nastiness.
It only clocked out at "insane" - the neighbours treat with the police levels on Rock/Pop, on classical the strain shows up on the Tutti's with large scale (Mahler, Ravel/Mussorsky - Pictures, St Saen - #3 etc), but the Baroque, Renaissance, sacral and early music I often favour for classical stresses them less and the result is very pleasing.
I suspect if I absolutely had to, I could live with the NeoFones reasonably happily (in a room no more than 25 Squaremeters) and I cannot say that of too many Speakers of my direct aquaintance (I do normally like my speakers BIG)....
Of course, I do not HAVE TO (my wife allows me bigger speakers and I have quite a range around).
Sayonara
PS, the designer is not from the Jordan/Bance dustcircle....
soongsc said:
The final shape of the dip is probably at least somewhat down to my own ideas.
The problem is that any such driver if the cone is not allowed to break up will roll off at some point due to the mass rolloff (and/or voice coil inductance).
If you push the breakup out far enough, which I felt was sonically preferable in principle to an earlier breakup in the region where the ear is most sensitive, you get this kind of dip, which in turn is not entierly unlike the BBC Dip and can help the speaker to avoid sounding spitty or too forward when played loud.
Clearly, above 5KHz reasonably well damped cone breakup is used to take the response up further, but at that point the human hearing rapidly looses resolution , so the breakup is not THAT BAD a thing.
Equally, if you have a really large wideband driver it is worth letting it break up softly at a very low frequency, Eckmiller set the cone breakup in his 12" 2-Way coax around 300Hz, with a crossover at 2KHz! The breakup region of the 2" Aluminum Dome however was pushed up to past 8KHz IIRC.
Anyway, I recommended back when to brian to push the notch to around 4-5KHz and to keep it modest. Took quite a few samples to achieve. A "flat" version was aparently also tried (which hence must have gone into breakup at around 3KHz) and which did not sound nice at all.
All in all I think the fairly effortlessness with wich the Drivers handles quite substantial LF input AND the dip make for a speaker that plays subjectively louder than many miniatures (especially with FR Drivers) without strain or nastiness.
It only clocked out at "insane" - the neighbours treat with the police levels on Rock/Pop, on classical the strain shows up on the Tutti's with large scale (Mahler, Ravel/Mussorsky - Pictures, St Saen - #3 etc), but the Baroque, Renaissance, sacral and early music I often favour for classical stresses them less and the result is very pleasing.
I suspect if I absolutely had to, I could live with the NeoFones reasonably happily (in a room no more than 25 Squaremeters) and I cannot say that of too many Speakers of my direct aquaintance (I do normally like my speakers BIG)....
Of course, I do not HAVE TO (my wife allows me bigger speakers and I have quite a range around).
Sayonara
PS, the designer is not from the Jordan/Bance dustcircle....
Konnichiwa,
In the current envoironment of ROHS legistlation in europe and the current "sue their pants off" mentality in the US and the fact that beryllium oxide is fairly toxic, I suspect - no.
But rigidity as such is not actually the answer, Contolled non-rigidity is much closer to an answer....
Sayonara
soongsc said:
In the current envoironment of ROHS legistlation in europe and the current "sue their pants off" mentality in the US and the fact that beryllium oxide is fairly toxic, I suspect - no.
But rigidity as such is not actually the answer, Contolled non-rigidity is much closer to an answer....
Sayonara
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