I should add that's why it's important to me to draw things out of the shadows and give people credit for the work they've done. In the little tiny pond of audio, we have had two-steps-forward, one-step-back as a result of corporate secrecy, not giving the real innovators credit, and confuse-em-with-BS marketing for more than fifty years. I know it's the standard corporate model for doing business (in this country, at least), but the open-source collaboration model is a good alternative.
Thanks, Kindhornman, for the tips about Kevlar. The commercial drivers have a very rough breakup region over more than an octave; interesting to realize it might be the matrix, not the Kevlar, that's responsible. In that event, the performance could all over the place, and you can't generalize.
Thanks, Kindhornman, for the tips about Kevlar. The commercial drivers have a very rough breakup region over more than an octave; interesting to realize it might be the matrix, not the Kevlar, that's responsible. In that event, the performance could all over the place, and you can't generalize.
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Now at least we have something that more people have listened to.
. Rather than each talking about something the other has not heard. It is also common in our country not to criticize the competition to death, but rather address the differences. This not only shows we look into more detail rather than totally ignoring the good side of other products, but also we still respect the effort others put into their work. I can tell you, if I am still developing, it means that if have found nothing out there that fits my expectations. I wish I could listen to some of the systems you are talking about first hand. Maybe I need tour the US some time again even though I spent over 15 years there enduring the racial abuse while I was a kid. Things got much better in the business environment, we were even able to work out cultural differences through communication, it could also have been similar southern relaxedness of TX.Looking at the data Jean-Michel provided, it seems like the Avant-Garde type horn should not be too far away in performance from the LeCleach horn, however, I have have to check which model actually had that bandwidth implementation, maybe Jean-Michel can shed some light on this?
And you can currently identify that it was the speakers? I have heard them as well as many horns being bad at audio shows, but I had also listened to them in different locations and driven by different equipment, and a variety of models. Each place sounded different. The main pus pose of listening to different technology based equipment is to really find just that bit that others might have done well, and make it a constructive experience.The Avant-Garde are one of the worst horns systems I've ever heard. I can't figure out how they can mess them up that bad. Really shockingly bad.
That Kevlar thing reminds me of a chat around here. Long ago while we were,young, some PhD got together and tried to convince manufacture here to jointly develop a cone with this different material. They were all excited and made the cone, and had a hell of a time trying to cut it. I later found out it was Kevlar.
Lynn, open source collaboration is good for inspiration, not for product development. This is simply because everyone have their own expectations, ideals, and there is no decision making mechanism to make critical decisions, so there is not way to focus efforts.
Lynn, open source collaboration is good for inspiration, not for product development. This is simply because everyone have their own expectations, ideals, and there is no decision making mechanism to make critical decisions, so there is not way to focus efforts.
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Diaphragm shape is just as critical as material. When we started to work on a 3inch driver, the first thing we changed from an existing design was the dust cap. Designing it to provide dispersion and minimizing the possibility of breakup we normally see in 1 inch metal dome drivers. The results came out as expected as found through Klippel scanning up to 20kHz, which they can go higher. A diamond cap was also tested with a different shape, it was expected to have less dispersion an increase high frequency response, again as expected. I don't recall seeing any deformation at 20KHz. The difficult part of diaphragms is to flex the way you want if to. Ted Jordan spend most of his life doing this, and certainly inspired lots of ideas. He has also tried a variety of suspension methods. I have a collection of his drivers, and have put some through Klippel Large Signal testing just to understand what different suspensions actually do.
Soongsc,
You just happened to grow up in a state, Texas that isn't exactly well known for being open for what they consider outsiders, I am sure your experience would have been very different here in California.
I have produced some cones in the past for others and some of the shapes that people choose for a cone are rather odd to say the least, I think they were decided upon more for aesthetic reasons than anything else. I once did a 10" cone for another company and the cone was so stiff that I could literally stand on the apex without collapsing the cone and I weighed about 175 lbs at the time. Of course this was supposed to be for a sub-woofer but it was more than overkill. I have been able to make shapes that would be rather difficult to do with paper, they could be done but would have made the molding rather tricky, I prefer curvilinear cones myself but I can see how a straight conic section cone may work for certain applications. The terminating angle can be very important in the cone as you would never in my opinion want a cone to go completely flat at the outside edge, it would loose it ability to retain shape and would have some very unusual bending modes and more than likely decoupling from the surround.
I would love to have one of the Klippel systems to study the cone behavior, one of the things I look forward to in the future but it is not as if there were not other studies done long ago with lasers and looking at the actual bending modes of cones in the past. This technical material is available in the loudspeaker compendium printed by AES and something that I studied many years ago.
You just happened to grow up in a state, Texas that isn't exactly well known for being open for what they consider outsiders, I am sure your experience would have been very different here in California.
I have produced some cones in the past for others and some of the shapes that people choose for a cone are rather odd to say the least, I think they were decided upon more for aesthetic reasons than anything else. I once did a 10" cone for another company and the cone was so stiff that I could literally stand on the apex without collapsing the cone and I weighed about 175 lbs at the time. Of course this was supposed to be for a sub-woofer but it was more than overkill. I have been able to make shapes that would be rather difficult to do with paper, they could be done but would have made the molding rather tricky, I prefer curvilinear cones myself but I can see how a straight conic section cone may work for certain applications. The terminating angle can be very important in the cone as you would never in my opinion want a cone to go completely flat at the outside edge, it would loose it ability to retain shape and would have some very unusual bending modes and more than likely decoupling from the surround.
I would love to have one of the Klippel systems to study the cone behavior, one of the things I look forward to in the future but it is not as if there were not other studies done long ago with lasers and looking at the actual bending modes of cones in the past. This technical material is available in the loudspeaker compendium printed by AES and something that I studied many years ago.
I have to give big Kudos to Jean Hiraga and friends as well as the Japanese enthusiasts who were putting together great sounding horn systems in the 1970s. I first got to hear them in the '80s. Their work changed my ideas about speakers forever.
I never got to hear the fabled Paris system you helped build, Pano, but I did hear a funky pair of unrestored Altec A5's about fifteen years ago at the San Francisco Audio Club.
That really surprised me. Although there was plenty that was wrong, there was also something really special about the sound. Gary Pimm was came along on that road trip to California, and we both noticed the same thing. The metallic harshness and grain-n-grit that I was expecting from the A7 wasn't there; it was a little soft at the top, and somewhat out of balance, but the sound was silky, sweet, and effortlessly dynamic in a way I hadn't heard from horns before. The over-the-top descriptions in "Sound Practices" magazine fell into place.
That's really the first time I started to take horns seriously. I was intimidated by the math, and all the conflicting research, but I knew that at least some of them could sound musical. On further research, it was the sectoral, Manta-Ray, and Bi-Radial horns that I disliked so much, with the ugly metallic coloration and no retrieval of spatial impression. That came down to diffraction and poor impulse response, which doesn't sound good in direct-radiators, either.
Soongsc, I wish you could hear some of the things we've been talking about. A well-tuned Altec multicell (1005 or better), with the right EQ (ask Pano), and the Altec Alnico woofer, is really something. No commercial system sounds anything like it. Dr. Geddes' Summa is very much worth a listen; we might disagree about electronics, but there's no question the Summa is flat, even-tempered, and a thoroughly well-designed system. The new prototype I'm working on, although not 100% done, sounded far better than anything at the RMAF show, and surprisingly close to the Ariel/BBC/Quad ESL57 sound. Even the spatial perspective is similar, which is remarkable considering how different the systems are.
Pardon my bluntness, but the horns at the RMAF show sounded like dog**** in comparison to the three systems mentioned above. All three are very, very good in absolute terms, regardless of efficiency, and I would take them over MBL's any day of the week. Part of the reason I've been so complacent about 100% finishing the new system is that I've realized just how good the Ariels have been all along, so I might as well take my time and make the new system something I can enjoy for the next ten or twenty years.
Returning to your comments, Soongsc, I'd also re-consider the merits of combining the OS and LeCleac'h profiles. You see, they do different things. The LeCleac'h, at least for T ratios between 0.707 and 0.8, is optimized for uniform (resistive) diaphragm loading over the working frequency range. They're acoustic transformers, optimized for flat response and impulse response. The polar pattern, although very smooth, is not constant-directivity, and mimics a direct-radiator. They sound like direct-radiators, but with 20 dB more headroom, and much more insight into the music, like an electrostat with unlimited dynamic range.
The OS is a waveguide, optimized for directivity control. Any transformer action is purely incidental. They do require serious equalization in the working band, at the Dr. Geddes level of expertise. I would never attempt it myself. The sound is very different than the LeCleac'h, much more intense and focussed, a sort of front-row right-there sound.
That really surprised me. Although there was plenty that was wrong, there was also something really special about the sound. Gary Pimm was came along on that road trip to California, and we both noticed the same thing. The metallic harshness and grain-n-grit that I was expecting from the A7 wasn't there; it was a little soft at the top, and somewhat out of balance, but the sound was silky, sweet, and effortlessly dynamic in a way I hadn't heard from horns before. The over-the-top descriptions in "Sound Practices" magazine fell into place.
That's really the first time I started to take horns seriously. I was intimidated by the math, and all the conflicting research, but I knew that at least some of them could sound musical. On further research, it was the sectoral, Manta-Ray, and Bi-Radial horns that I disliked so much, with the ugly metallic coloration and no retrieval of spatial impression. That came down to diffraction and poor impulse response, which doesn't sound good in direct-radiators, either.
Soongsc, I wish you could hear some of the things we've been talking about. A well-tuned Altec multicell (1005 or better), with the right EQ (ask Pano), and the Altec Alnico woofer, is really something. No commercial system sounds anything like it. Dr. Geddes' Summa is very much worth a listen; we might disagree about electronics, but there's no question the Summa is flat, even-tempered, and a thoroughly well-designed system. The new prototype I'm working on, although not 100% done, sounded far better than anything at the RMAF show, and surprisingly close to the Ariel/BBC/Quad ESL57 sound. Even the spatial perspective is similar, which is remarkable considering how different the systems are.
Pardon my bluntness, but the horns at the RMAF show sounded like dog**** in comparison to the three systems mentioned above. All three are very, very good in absolute terms, regardless of efficiency, and I would take them over MBL's any day of the week. Part of the reason I've been so complacent about 100% finishing the new system is that I've realized just how good the Ariels have been all along, so I might as well take my time and make the new system something I can enjoy for the next ten or twenty years.
Returning to your comments, Soongsc, I'd also re-consider the merits of combining the OS and LeCleac'h profiles. You see, they do different things. The LeCleac'h, at least for T ratios between 0.707 and 0.8, is optimized for uniform (resistive) diaphragm loading over the working frequency range. They're acoustic transformers, optimized for flat response and impulse response. The polar pattern, although very smooth, is not constant-directivity, and mimics a direct-radiator. They sound like direct-radiators, but with 20 dB more headroom, and much more insight into the music, like an electrostat with unlimited dynamic range.
The OS is a waveguide, optimized for directivity control. Any transformer action is purely incidental. They do require serious equalization in the working band, at the Dr. Geddes level of expertise. I would never attempt it myself. The sound is very different than the LeCleac'h, much more intense and focussed, a sort of front-row right-there sound.
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Klippel has some interesting examples on their site which can be downloaded. They also have data viewing software available as well. What I like about the system is they let you replay the motion any time you want, and can decouple different modes which is quite useful for understanding how the motion effects sound. Lots of previous analysis methods lack the 3D force involvement. I have read many AES publications without satisfaction.
Every part of the cone seems critical, I don't think we should rule out flat termination because you want smooth transition to the surround. For small drivers with stiff cones, it does become a problem because if you have sufficient damping at the surround, the mass might be high enough to effect the efficiency. Larger cones give a bit more room to play around with the shape and termination. I remember Bandor,used a wood mold to turn their cones, and I can understand why. I think it is important to look at different designs and understand the trade offs. I like stiff cones, but the challenge I establish is get rid of the breakup mode while preventing the cone from modal operation as much as possible. This cannot be done with soft material because the modal operation starts quite early and the materiel tend to absorb some energy in initial VC motion. Jordan drivers use very thin cone material that it works in the modal range just like paper but without the low level detail absorption. The softness due to thinness actually provides a good match with the surround such that the residual energy damps out quite well if not as good as paper. I have demonstrated in the Enable thread that it can be damped out even faster. This is mainly the upper frequency part. The lower frequency part is where motor and suspension design is critical. I intend to get into that after the cone problem is optimized, and hopefully it is successful.
It has always worried me where a modern composer has taken an unfinished symphony of one of the greats and completed the work. There are a few of these. On first hearing the added content, I have had a perception of - who is this guy, but gradually realise that the revising composer has the heart of the symphony, and has justified being perhaps compelled to complete the work.
Sure Peter Walkers goal with the ELS57 was a you are there experience. He did the thing of a may of these lines up on a stage separated from the audience by a thin obscuring curtain. This was done with Quad 2 and 22 valve amps fed by unknown source. But the fact that he thought this was so realistic shows it must have been pretty darned good. I heard my first ELS67 (mono) in a teachers flat 53 years ago. It was playing music from the BBC Third Network. Solo piano music Chopin or Mozart whatever.
Those of us who still have good working ELS57.s are very fortunate to have such a reference speaker. I have always felt that a more power ELS57 with more authority or dynamic performance and the point source accuracy of imaging could be improved.
Going down a sort of Ariel route has given me most of my goal. So I have ended up finding what are kindred spirits on this blog and others where I found a guy with similar inspiratiions and verity that can get us further towards the 'common' goal.
It is so easy to miss the boat with changes that in the past we could be close to a fantastic speaker and move past it to some less pleasing alternative to what it might have been.
However, with the Klippel and other analytical stuff we have now the opportunity integrity and verity withstanding a way of shining the torch to find the pot of gold.
Lynns frankness and openness has reminded us from time to time to be rational about what is going on in the whole arena of sound reproduction, to our own faults through a project that looks as though it will bear fruit.
There are a few guys out there doing this, and we must thank them because they are taking us all forward in a compelling interest.
The Be variant may be just what the Radian 745neo needed to match the direct radiator on step pulse CSD and the aural quality we require
The crossover is I believe the biggest issue ahead and this is crucial to the project success.
Hi Lynn,
Certainly wish some of those systems were here, in China, Hong Kong, Macau, etc. makes it a lot easier to get to and combine into trips.
As a leisurely commercial endeavor, I try to suppress my personal opinion about other products unless I can explain the difference more precisely. This is the attitude I take even when having demonstrations in store in pure respect to the customers. The responsibility of sales to to help the customers find a system that they like in a pleasant way. If they like what we think are cr*p, one day when they finally realize! They will at least know what to turn to, and I have gone through such learning process as well.
When the US started rejecting Chinese network products in government units, I knew somerhing would blow up, and then came the Snowden case. So now what, the trend will be that each county with such worries are going to have to develop their own network chips to prevent back door snooping. Once trust is broken, it is hard to mend.
Going back to audio, their must be a reason why good products cannot reach around the world. Good computer and communication devices sell well in other countries even though the market share varies. So we really need to think what needs to be done in audio. Sound quality may well be only 30%'ofmthe reason someone will buy a speaker. One paint supplier asked to use the Lullaby to show how good their paint was at a show. It brought lots of customers, but they were asking where they could get the speaker. Lots of European designs really look special in a room, and I think it is important to blend design factors with sound reproduction to have a product people will love.
Certainly wish some of those systems were here, in China, Hong Kong, Macau, etc. makes it a lot easier to get to and combine into trips.
As a leisurely commercial endeavor, I try to suppress my personal opinion about other products unless I can explain the difference more precisely. This is the attitude I take even when having demonstrations in store in pure respect to the customers. The responsibility of sales to to help the customers find a system that they like in a pleasant way. If they like what we think are cr*p, one day when they finally realize! They will at least know what to turn to, and I have gone through such learning process as well.
When the US started rejecting Chinese network products in government units, I knew somerhing would blow up, and then came the Snowden case. So now what, the trend will be that each county with such worries are going to have to develop their own network chips to prevent back door snooping. Once trust is broken, it is hard to mend.
Going back to audio, their must be a reason why good products cannot reach around the world. Good computer and communication devices sell well in other countries even though the market share varies. So we really need to think what needs to be done in audio. Sound quality may well be only 30%'ofmthe reason someone will buy a speaker. One paint supplier asked to use the Lullaby to show how good their paint was at a show. It brought lots of customers, but they were asking where they could get the speaker. Lots of European designs really look special in a room, and I think it is important to blend design factors with sound reproduction to have a product people will love.
*SNIP*
*/SNIP*
Well, that's understating it a bit- the waveguides in question are 90 degree I believe, and 1M is VERY close for listening to large systems like these, so it'd be some amount higher output required from the device than you're stating.
I agree, home listening levels should be pretty trivial for a HF section of a system like the Summa, case in point, my miniscule modified neo seleniums can do any level they want in my rig without the slightest sign of strain (I use waveguides similar to in the Summa, but not exactly the same, but rather a close approximation of OSWG.
*/SNIP*
Well, that's understating it a bit- the waveguides in question are 90 degree I believe, and 1M is VERY close for listening to large systems like these, so it'd be some amount higher output required from the device than you're stating.
I agree, home listening levels should be pretty trivial for a HF section of a system like the Summa, case in point, my miniscule modified neo seleniums can do any level they want in my rig without the slightest sign of strain (I use waveguides similar to in the Summa, but not exactly the same, but rather a close approximation of OSWG.
Did some measurements of the Radian 745 NEO/beryllium today. Here's what I have so far:
This measurement was taken with no crossover or equalization…just the driver on the Azurahorn AH-425. Drive level is arbitrary.
Below it appears with an overlay of the regular 745 driver, with ferrite magnet and aluminum diaphragm.
This measurement was taken with no crossover or equalization…just the driver on the Azurahorn AH-425. Drive level is arbitrary.
Below it appears with an overlay of the regular 745 driver, with ferrite magnet and aluminum diaphragm.
Art
There are a few details that you are not considering.
First, HOMs and diffraction (heretofore just diffraction) are linear and hence do not change with level. This means that you will not detect diffraction in your test, only nonlinearities.
Second, since the levels that nonlinearities are detected at in your test are extremely high, no sane owner of my speakers would ever observe such a distortion since to do so would be seriously risking ones hearing.
This means that nothing that I claimed about my speakers is in any way negated or reinforced by your test. It is simply irrelevant as far as my speakers in home listening rooms is concerned.
What is not clear is if the audibility of diffraction rises faster than the audibility of nonlinearity, which, as I said, your test is immune to (the diffraction) being at a fixed playback level. It would take a rather sophisticated and well controlled test to sort out if this is true or not.
But I do have one data point. (One that I believe is very common). My previous speakers were JBL 4430's. A decent design, but clearly not one with low diffraction. They most certainly did begin to sound bad at higher SPLs even in my home listening room (which has not changed at all since I had those speakers). Since it is unlikely that this audible distortion, by both your test and my test, is nonlinearities at typical home listening levels, I have to conclude that it was diffraction. A diffraction reduced waveguide speaker does not exhibit the same effect despite having the same sized driver and waveguide coverage.
Why your test and my test of nonlinear distortion (both of which would be immune to diffraction) conclude different things I cannot begin to explain.
Thanks for this useful comparison. It shows that really both the Be and the ceramic Al are not too far apart in the main audible range. It would be great to have the Neo Al version which will still probably show the gradual but smoother drop off of the ceramic. If Lynn stays with the 745 Neo Al at least the Be could be added later, but I feel the Be is too ragged for the price in the 12K up. We can see why Lynn was considering a super tweeter as the treble does roll off a bit early.Did some measurements of the Radian 745 NEO/beryllium today. Here's what I have so far:
This measurement was taken with no crossover or equalization…just the driver on the Azurahorn AH-425. Drive level is arbitrary.
Below it appears with an overlay of the regular 745 driver, with ferrite magnet and aluminum diaphragm.
I tried to source the Azure AH-425 but the website seems inactive. Would Lynn be looking for a group buyu if he finalises on the AH-425. I am considering the 1" AH550 which seems to extend the treble to 15kHz with the JBL2420, so wht about the Radian equivalent Neo Al or Be
I'm actually quite happy with the HF shape of the beryllium version, which looks to be well-suited for extending with either a ribbon or AMT. I understand that a significant amount of the aluminum diaphragm's top-end energy consists of ringing, and I'd rather do without that.
Even without optimization, the combination of the Aurum Cantus G3 ribbons sounded very promising with the beryllium drivers. I had tried the ribbons with the regular 745's, but the 745's sounded better on their own.
It could very well be that the neodymium 745 with aluminum diaphragm would be a nice compromise for use without a tweeter (Lynn liked it a lot), but I must admit that I like the idea of having wider dispersion at the top end.
Even without optimization, the combination of the Aurum Cantus G3 ribbons sounded very promising with the beryllium drivers. I had tried the ribbons with the regular 745's, but the 745's sounded better on their own.
It could very well be that the neodymium 745 with aluminum diaphragm would be a nice compromise for use without a tweeter (Lynn liked it a lot), but I must admit that I like the idea of having wider dispersion at the top end.
Martin Seddon of Azurahorn contributes to this thread as "TrueTone". He's still making the AH425; I received a new pair not that long ago. The AH425 is done, finished, no more work to do, and Martin is the supplier. I commissioned the AH425, and I'm pleased that Martin and Bjork Kolbrek use them in their own systems (Martin with the Yamaha JA-6681 and Bjorn with an Altec 288).
It should be noted the Radian 745PB ceramic does not use the same phase plug as the Neodymium version, and diaphragms do not interchange between the two models. The beryllium diaphragm for the Neo version, though, does interchange with the aluminum diaphragm (for the Neo magnet).
I have no explanation for the small dip at 2.5 kHz, which appears at the same frequency as the dip shown by the GPA 288 Alnico.
The aluminum Neo version, if I recall the measurements correctly, has an even more enthusiastic 10~20 kHz region than the ceramic version, and is about 2 dB more efficient. It definitely needs a lowpass filter if a supertweeter is contemplated.
The simulation below, created by Bjorn Kolbrek, shows a comparison of power factor for the AH425 versus a smoothed conical. The thin black trace is power radiated out the horn, and the thin red trace is power reflected back to the diaphragm. The heavier black and red traces show the power factors for a same-size conical horn with a smoothly radiused throat transition region. The need for in-band equalization is apparent.
Soongsc, this is why I recommended in a previous post to not combine two different types of horn; they do different things, and are optimized for different sets of parameters. If you combine them, the LeCleac'h will lose the PF optimization, and the OSWG will lose the desired directivity pattern. I now suspect it's not possible to have both qualities at the same time. If you want little or no EQ, that points in the LeCleac'h direction. If in-band EQ is not a problem for you, then OSWG is an option. Dr. Geddes' suggestion to measure over a wide array of points when designing the OSWG equalization is exactly what you should do if you choose an OSWG.
The physical AH425 is pretty close to Bjorn's simulations, and meets the goal of uniform diaphragm loading versus frequency (an acoustic transformer with flat on-axis response). The rest is up to the compression driver.
It should be noted the Radian 745PB ceramic does not use the same phase plug as the Neodymium version, and diaphragms do not interchange between the two models. The beryllium diaphragm for the Neo version, though, does interchange with the aluminum diaphragm (for the Neo magnet).
I have no explanation for the small dip at 2.5 kHz, which appears at the same frequency as the dip shown by the GPA 288 Alnico.
The aluminum Neo version, if I recall the measurements correctly, has an even more enthusiastic 10~20 kHz region than the ceramic version, and is about 2 dB more efficient. It definitely needs a lowpass filter if a supertweeter is contemplated.
The simulation below, created by Bjorn Kolbrek, shows a comparison of power factor for the AH425 versus a smoothed conical. The thin black trace is power radiated out the horn, and the thin red trace is power reflected back to the diaphragm. The heavier black and red traces show the power factors for a same-size conical horn with a smoothly radiused throat transition region. The need for in-band equalization is apparent.
Soongsc, this is why I recommended in a previous post to not combine two different types of horn; they do different things, and are optimized for different sets of parameters. If you combine them, the LeCleac'h will lose the PF optimization, and the OSWG will lose the desired directivity pattern. I now suspect it's not possible to have both qualities at the same time. If you want little or no EQ, that points in the LeCleac'h direction. If in-band EQ is not a problem for you, then OSWG is an option. Dr. Geddes' suggestion to measure over a wide array of points when designing the OSWG equalization is exactly what you should do if you choose an OSWG.
The physical AH425 is pretty close to Bjorn's simulations, and meets the goal of uniform diaphragm loading versus frequency (an acoustic transformer with flat on-axis response). The rest is up to the compression driver.
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