also are GRS ribbons rebadged founteks or are they fountek knock offs ? they are half he price, though i want the narrow 8mm fountek and the GRS seems wider.
somebody on partsexpress wrote a review of GRS ribbon where he said that because he has spent thousands of dollars on vaccum tubes that certifies his golden ears and gives him supersonic hearing and he has determined that GRS ribbon doesn't reach 20 khz even though according to published measurements it is virtually flat to 40 khz ...
who is BSing here the - the vacuum tube guy or GRS ? i know the real founteks do 40 khz because Vance Dickason measured them, but is the GRS fountek real ?
basically let's say you put the founteks in an array along with some prosound subwoofers in the same array - will the bass blow the ribbons out ?
i only want them from 7 khz and up. the other option is
https://www.parts-express.com/HiVi-RT1C-A-Planar-Isodynamic-Tweeter-297-400?quantity=1
but apparently it is not as efficient ( again, according to reviews, which i don't know if they can be trusted )
such a wide spread in prices with ribbons - from $35 HiVi to $60 GRS to $150 fountek to $250 Aurum Cantus to $500 RAAL
yes i know HiVi is not a ribbon, but it still hits 40 khz - or does it ?
i just want loud and wide dispersion supertweeter array. i don't care if its true ribbon, isodynamic or AMT - as long as it works.
but AMTs all seem to be wide for whatever reason.
i want 1/2 inch or narrower supertweeter line source above 7 khz or so.
somebody on partsexpress wrote a review of GRS ribbon where he said that because he has spent thousands of dollars on vaccum tubes that certifies his golden ears and gives him supersonic hearing and he has determined that GRS ribbon doesn't reach 20 khz even though according to published measurements it is virtually flat to 40 khz ...
who is BSing here the - the vacuum tube guy or GRS ? i know the real founteks do 40 khz because Vance Dickason measured them, but is the GRS fountek real ?
basically let's say you put the founteks in an array along with some prosound subwoofers in the same array - will the bass blow the ribbons out ?
i only want them from 7 khz and up. the other option is
https://www.parts-express.com/HiVi-RT1C-A-Planar-Isodynamic-Tweeter-297-400?quantity=1
but apparently it is not as efficient ( again, according to reviews, which i don't know if they can be trusted )
such a wide spread in prices with ribbons - from $35 HiVi to $60 GRS to $150 fountek to $250 Aurum Cantus to $500 RAAL
yes i know HiVi is not a ribbon, but it still hits 40 khz - or does it ?
i just want loud and wide dispersion supertweeter array. i don't care if its true ribbon, isodynamic or AMT - as long as it works.
but AMTs all seem to be wide for whatever reason.
i want 1/2 inch or narrower supertweeter line source above 7 khz or so.
if ya want 1/2 inch then the ribbon is they way. The planer can do it too
thing to keep in mind about these drivers is the response is not at all flat and you will need to trap or rake them if ya want truly flat all the way out
all ribbons have a rising response to a peak then a falling response. This curve is an interaction between diaphragm width, mass, and the slot load of the magnet structure. Raal gets a fairly linear but still rising response with peak at around 20 k or so BUT they use a shaped magnet to mitigate the slot load AND a very thin foil about 4 X thinner than the GRS or Fountek. I have built many this way and they work well but can be fragile if ya do anything wrong
Looking at the GRS ya have a typical ribbon in a rectangular slot response that rises about 7db from 5k to 12k then back down 5 db at 20 k . So to get it flat you can rake it and loose response above 12k ( fine for most people) OR trap it for flat all the way out. HOWEVER you will loose about 5-7db of sensitivity by the time you get it flat. So many manufactures are giving you the sensitivity at or near the peak. Quite deceiving.
These ribbons use a fairly robust 12 micron foil with a clever elastomer termination. It should have no trouble with the woofers next to them.
MOST "reviews" are nearly worthless. Especially the ones at PE
thing to keep in mind about these drivers is the response is not at all flat and you will need to trap or rake them if ya want truly flat all the way out
all ribbons have a rising response to a peak then a falling response. This curve is an interaction between diaphragm width, mass, and the slot load of the magnet structure. Raal gets a fairly linear but still rising response with peak at around 20 k or so BUT they use a shaped magnet to mitigate the slot load AND a very thin foil about 4 X thinner than the GRS or Fountek. I have built many this way and they work well but can be fragile if ya do anything wrong
Looking at the GRS ya have a typical ribbon in a rectangular slot response that rises about 7db from 5k to 12k then back down 5 db at 20 k . So to get it flat you can rake it and loose response above 12k ( fine for most people) OR trap it for flat all the way out. HOWEVER you will loose about 5-7db of sensitivity by the time you get it flat. So many manufactures are giving you the sensitivity at or near the peak. Quite deceiving.
These ribbons use a fairly robust 12 micron foil with a clever elastomer termination. It should have no trouble with the woofers next to them.
MOST "reviews" are nearly worthless. Especially the ones at PE
i have a feeling that the rising response is due to directivity / beaming.
that is if you look at all the off-axis curves they average out to flat.
on-axis is rising but off-axis is falling and average is flat.
up to about 10 khz that is with Radians where they ALL begin to roll off ( including the on-axis ) and that is probably due to spacing between bar magnets putting a limit on a frequency where planar can act as a piston ...
by comparison ribbons are driven uniformly and don't exhibit this roll off at 10 khz ... or at any khz really ...
but ribbons do not form an airtight seal so they can't work as mids ...
this way ribbons and planar compliment each other where planars make good mid-tweeters and ribbons make good supertweeters
i think depending on size of planar and ribbon somewhere around 5 khz is a good place to cross them over to each other ...
yes of course, thats the width part, however the suden hump you see at the higher freqs that departs from the linear rise due to beaming is in part a slot loading issue
not exactly flat, you still have the hump at higher freqs BUT now its a strong roll off above the humps peak off axis. Also If you listen off axis you still have the peaked energy in the room giving an overly bright sound anyway. Some hear this and it sounds exciting at first and fatiguing eventually
the roll off happens after the linear rise. They all do it. You can trap them and get flat.
if you make the gap tight enough, less than about 1/2 mm then they can. I have ribbon protos that do this and show a strong difference in lower freq response. In fact I have a 100mm by 15mm that can be used to 500 hz. However its not practical from a production standpoint to make ribbons with a really tight gap and if corrugated they will slap the magnets under hard drive. BTW Small Ribbons with a larger edge gaps do exhibit large amounts of distortion below about 1.5kHz. This is due to aerodynamic issues at the ribbons edge launching its own wave. Planers dont have this issue. Ive noticed that RAAL show a fuzzy looking graph below that point. The distortion data is not flattering down there. If the gaps are small enough it gets WAY better. In fact an order of magnitude better by measurement but not sure at normal listening levels that its an issue? Maybe more as the volume goes up? Really large ribbons like in an Apogee get around this as the movements are so small.
Agree
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that said however you can manipulate ribbon width/ magnet slot size shape/ etc to get a near flat response from the smallest ribbons. Look at the difference in response curves between the GRS RT3.0 (larger wider ribbon with deep slot) VS the GRS 1.R (less wide and likley smaller magnets/less deep slot ). The wider ribbon has a strong hump and rise yet the narrower ribbon is near flat and its less deep slot avoids the hump better. The specs from them however are questionable as they claim similar useful freq bandwidth. I have had the GRS 3.0 and it does measure as posted. It worked well above about 4 khz. Below that it didnt sound well and if I remember the CSD didnt look good eather down there.
current iteration of my super duper end game ribbon array design calls for 10" radian
https://audioxpress.com/article/tes...bbon-transducer-from-radian-audio-engineering
crossed over to 8mm wide Fountek
https://audioxpress.com/article/test-bench-fountek-neocd2-0-high-end-ribbon-tweeter
at 3.5 khz
unless you can think of a cheaper driver combo that can replace it ...
i am trying to hit about 500 hz in an array with that planar ...
biggest issue is the main diaphragm resonance and where you want to cross over. Generally they spec the usable frequency response at or very near the main resonance and that is a bit less than honest . Sure you can do it BUT its often colored sounding used that way
It look like Radian has set what I would consider a good main resonance for this sized planer, around 120-130 hz So crossing at 500 should avoid any problems there.
However I suspect bang for buck on the planers will be the big GRS at much less money. Its main resonance is more like 300 hz? BUT if crossing at 500 then that might be fine and if not a bit of extra damping may work. This is done with some acoustic resistance. I often do it with a paper towel . Yes a simple cloth or even paper towel from the rolls ya buy at the grocery store works well. Just spray some adhesive like "super77" on towel, let dry a min or two, then attach to back side of driver. Letting it dry a bit before apply will make so you can easily remove if ya want. You can tune the amount of resonance damp by size or density of resistive "cloth".
IF doing a dipole however I dont want any cloth on backside of the tweeter. Dipoles that have attenuated or missing rear wave IMO dont sound right. Not sure if your doing a dipole but the tweeter you mention is not
Anyway "bang for buck" in what ya want to do may be better served by the big GRS planer. So long as ya dont want to cross lower than about 500 anyway.
As for the ribbon I have used that one, I think anyway? It looks to me like the GRS 3.0? I had it when it was labeled as something else about 2 years ago. its quite good so long as its crossed above 3-4khz. It goes lower BUT its colored by the cavity resonance of its chamber imo and the tensioned flat foil may have issues below there also. Flat is a great way to avoid the resonances corrugated ribbons have in the higher freqs BUT there are issues below say 3khz and hard drive. on the small units.
Anyway seems to me the GRS 3.0 is same driver and probably much cheaper
Some times I will by one unit of each and measure/ listen. If I was ready to spend a ton on a line of radians I would buy at least one GRS and test first. Not out that much if it doesn't work
It look like Radian has set what I would consider a good main resonance for this sized planer, around 120-130 hz So crossing at 500 should avoid any problems there.
However I suspect bang for buck on the planers will be the big GRS at much less money. Its main resonance is more like 300 hz? BUT if crossing at 500 then that might be fine and if not a bit of extra damping may work. This is done with some acoustic resistance. I often do it with a paper towel . Yes a simple cloth or even paper towel from the rolls ya buy at the grocery store works well. Just spray some adhesive like "super77" on towel, let dry a min or two, then attach to back side of driver. Letting it dry a bit before apply will make so you can easily remove if ya want. You can tune the amount of resonance damp by size or density of resistive "cloth".
IF doing a dipole however I dont want any cloth on backside of the tweeter. Dipoles that have attenuated or missing rear wave IMO dont sound right. Not sure if your doing a dipole but the tweeter you mention is not
Anyway "bang for buck" in what ya want to do may be better served by the big GRS planer. So long as ya dont want to cross lower than about 500 anyway.
As for the ribbon I have used that one, I think anyway? It looks to me like the GRS 3.0? I had it when it was labeled as something else about 2 years ago. its quite good so long as its crossed above 3-4khz. It goes lower BUT its colored by the cavity resonance of its chamber imo and the tensioned flat foil may have issues below there also. Flat is a great way to avoid the resonances corrugated ribbons have in the higher freqs BUT there are issues below say 3khz and hard drive. on the small units.
Anyway seems to me the GRS 3.0 is same driver and probably much cheaper
Some times I will by one unit of each and measure/ listen. If I was ready to spend a ton on a line of radians I would buy at least one GRS and test first. Not out that much if it doesn't work
yes i agree the Radian is too similar to GRS to justify 3X price.
but things seems to get more complicated with true ribbons.
for one the GRS don't seem to come in narrow 8 mm width - at least not on partsexpress
secondly not sure if GRS use sandwich diaphragm or just aluminum ?
i am not concerned with blowing the ribbon with too much input - my concern is blowing it with bass from the subs. i need a ribbon that can take 130 decibel bass, be inexpensive and repairable.
but things seems to get more complicated with true ribbons.
for one the GRS don't seem to come in narrow 8 mm width - at least not on partsexpress
secondly not sure if GRS use sandwich diaphragm or just aluminum ?
i am not concerned with blowing the ribbon with too much input - my concern is blowing it with bass from the subs. i need a ribbon that can take 130 decibel bass, be inexpensive and repairable.
I doubt very much anyone is using a true sandwich
The GRS I believe is 10mm wide. I doubt it will make a noticeable difference in practice. Years back I determined anything below about 12mm wasn't necessary BUT my hearing at the time was limited to 15Khz.
I would say the only way to know would be to test. Buy one, place it were it will be near sub and trip the breakers ha
I doubt you will have an issue
Those ribbons are easy to replace btw. Ive even used the 16 micron foil from grocery store and it worked quite well but 20K was down about 3 db.and its goes down to about 6 ohm. I suppose the ribbon foils may be available from PE?
Biggest issue with making your own ribbons is getting the exact width. Just 1/2mm change will alter the sensitivity a db or two BUT with some practice its not that hard.
The GRS I believe is 10mm wide. I doubt it will make a noticeable difference in practice. Years back I determined anything below about 12mm wasn't necessary BUT my hearing at the time was limited to 15Khz.
I would say the only way to know would be to test. Buy one, place it were it will be near sub and trip the breakers ha
I doubt you will have an issue
Those ribbons are easy to replace btw. Ive even used the 16 micron foil from grocery store and it worked quite well but 20K was down about 3 db.and its goes down to about 6 ohm. I suppose the ribbon foils may be available from PE?
Biggest issue with making your own ribbons is getting the exact width. Just 1/2mm change will alter the sensitivity a db or two BUT with some practice its not that hard.
only replacement ribbons i saw on PE are for Aurum Cantus, which is even more expensive than real Fountek.
any opinions on it ?