Of course, Azurahorn -Le Cleac'h Acoustic Horns - Products
Great!
Congrats Gary on auditioning your system last week! Those photos certainly show a very enthused and pleased audience. And I’m also very glad to hear that they all preferred having the RAAL Lazy ribbons online, and apparently regardless of the recording.Yesterday a bunch of Seattle-area audio enthusiasts braved wild windstorms and power outages to attend the biannual DIY Showcase, co-hosted by Pacific Northwest Audio Society and Sound DIY. It seemed to be a nice opportunity for my speakers to be heard by a larger number of listeners. The rented cargo van had lots of space, so I brought a complete system, using my server as a source.
The server runs JRiver MC20 connected via USB to the exaSound e20 mk ii, the latter's balanced outputs feeding the Amity amplifiers. The Amity amps drive the 416's, 745's and RAALs. The subs are driven by their own plate amps.
By the way, further efforts to integrate the RAAL Lazy Ribbons have been quite successful. In listening comparisons (ribbons vs no ribbons), everyone preferred the ribbons.
Happy listeners shown below...
Gary Dahl
Thus, might it not be a question of whether most of the audience were too old to hear the very top end of what the ribbons could deliver from the recording, but rather the Lazy ribbons' sonic qualities at delivering those highs, beyond the range of your horns?
On the other hand, my take on what Lynn says here is that towards that top end (e.g. beyond 7kHz?) tonality isn’t much of a factor in what we hear. But if that’s true then what was it that prompted the guys at the show to prefer having the ribbons in the system than not?
Any other comments or speculations about what the Lazys did for the top end, and perhaps even for below it?
ps: I screwed up with trying to add a smilie. I tried to drag it.
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This is exactly my thought too!
I have made two full range drivers from scratch some 20 years ago and i used field coils because it was easy and relatively cheap
I do think it is a VERY good idea to use it but i cannot see way it should be so expensive, for small production runs it is actually cheaper than most to make. For prototyping it should be a no-brainer!
//Anders
Shhh or the car makers will bring back the side valve engine for our automobiles. With modern auto engine technology, bringing the side valve up to date,so it could rev to 8000 RPM. Boy would that go.
There is still some life in Art Deco yet.
But I do like the idea, but where do you stop.
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I think it's like most things in "Hi End" audio - low volume manufacturing. It's just brutal to make this into a real business with such low volumes - so the pricing is often a multiple of 10 or more from what it should be.
I believe there are at least 2 manufacturers of electro-magnet drivers in China.. one is Line Magnetic (..but I can't remember the others):
????????
-that 18" driver looks like a copy of the WE driver in the Mirrophonic.
Most manufacturers that do this though really rely on low volume manufacturing of Loudspeakers (and/or other items like Line Magnetic) that use their drivers - or they just wouldn't be a viable business in the long term no matter how low their other costs are.
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In a typical short gap speaker motor assembly I can't see any practical reason to use an electromagnetic design. If as is typical and the top plate has been run up into the saturation level what possible advantage could there be? Why would you lower the gap energy if the speaker was designed around a saturated top plate or pole piece, to what advantage? If you lowered the gap energy you could tilt the FR to bring up the appearance of bass but for what other reason besides that is there to do this? Permanent magnets would seem to be so inexpensive to build why would you spend the time to go backwards?
Wolf von Langa started by making field-coil versions of the classic Altec 288, 416, and 515 drivers. All of these are underhung (long gap, short voice coil).
The field-coil setup lets the owner saturate the gap, which of course will alter the sound of the driver. At lower power settings, it would behave (I guess) more like the Alnico originals.
Turning up the power on a FC loudspeaker would have several effects all at once, with the increase in volume and uptilt in frequency response being the most obvious. From the limited listening I've done with these things, it does indeed sound different than Alnico (when field strengths were equalized), but I wasn't personally sure it was better. For lack of a better word, it sounded just a bit more subtle and delicate, a sort of gentler sound, compared to the snap of Alnico.
Turn up the power, and it had all the snap you could ask for ... but that's what you'd expect with a big increase in BL factor and VC gaps moving towards saturation. I think the real appeal is tunability. Oddly enough, the same tunability could allow for precise matching of the efficiencies of the L and R drivers, which is a minor hassle with Alnico and ceramic magnets.
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Retro usually means easier to make, with the exception of vacuum tubes, which can use pretty exotic techniques (like explosion-formed plate assemblies).
Little things like long-forgotten glues and paper slurries used to make cones can also be awkward to replicate, because these were considered proprietary and records were lost over time. Hemp paper was a premium high-grade paper, right through the Twenties and early Thirties, until it became a casualty of the Drug War. Some aspects of audio disappeared completely, except for the collectors.
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Another factor is the cost of copper. There is usually a lot of copper weight in a field coil woofer. I once tried to talk the folks at Dayton Audio into doing FC versions of some of their drivers, since FCs were going for such big bucks. The cost of copper vs cost of neo or ferrite was one of the points of concern. I suggested aluminum wire, but sourcing enameled aluminum wire was also an issue. So the idea just faded...
Can someone convince GPA to build a re-issue 515a complete with phenolic spider and rolled paper surround? And while they're at it, make sure it has that "period correct" tiny dust cap vent, and hammered finish. A pair just went for $2,600 on ebay with 62 bids. There has to be a business model in there somewhere!
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Totally agree. It is good to get all this out in the open to debug some myths or clarify some of the truths about what these retro reproducers etc really can do and cannot do. Magnet metallurgists could definitely make a super variant on Alnico V, cobalt samarium or other alloy that improves on say Alnico V that becomes a must have. We must rejoice that we can get fantastc results with what we can afford, and the current project meets that criterion for many.
Why pay for rarity unless that is your paramount goal and not sound reproduction. In todays money $5000 can make an unbeatable DIY system
Many of us have done this for years.
The ribbons' sonic qualities are definitely important, but not the only factor in the tonality of the highs; I have personally been a lot happier with the ribbons since replacing the Lundahl interstage transformers with the O/Netics.
I don't think anyone had any trouble hearing the ribbons; even at the frequency they come in, their presence or absence is pretty obvious.
To me, there is still a bit of ribbon coloration present. I'm thinking of trying a steeper slope.
Gary Dahl
Gary,
This seems to follow what I have observed. Even when we think we don't hear those high frequencies we do in some way and can detect that high frequency energy, especially when you remove it and put it back. Some will say it is the side bands or lower harmonics that we are picking up on but I don't know that I believe that is the only explanation. I know earlier you said your high frequency hearing acuity has diminished with age and the loud environment that you work in but you are still aware of those tones. I still don't believe we have figured out all there is to the way we perceive sound, is it only with the ears or is there more to it? I am not talking about the lower frequency range where we do understand bone conduction and such.
This seems to follow what I have observed. Even when we think we don't hear those high frequencies we do in some way and can detect that high frequency energy, especially when you remove it and put it back. Some will say it is the side bands or lower harmonics that we are picking up on but I don't know that I believe that is the only explanation. I know earlier you said your high frequency hearing acuity has diminished with age and the loud environment that you work in but you are still aware of those tones. I still don't believe we have figured out all there is to the way we perceive sound, is it only with the ears or is there more to it? I am not talking about the lower frequency range where we do understand bone conduction and such.
Have you compared prices of used GPA units to original altecs on selling site? It's probably like 2:1 . It's hard to give GPA away
What ever happened to your wives folks
Look at the magazines up to 70's . They are full of huge speaker boxes with smiling girls next to them and now? ..
Limono,
So very true. Except for real PA sound systems and the very rare diy builder the days of large diameter speakers has come to an end. I know some here are convinced you need a very large diaphragm sized cone driver and very low excursion to get clear low frequencies that is far from real, many myths to this. The myth of doppler shift from a moving cone is the biggest one driving this need for large cones. In DBLT the doppler shift from a moving cone is not detectable. Some also just have nostalgia for these systems we grew up with, it really is mostly that. A smaller cone size solves so many problems for those trying to limit the number of crossover points without all the gyrations to find that magic speaker that doesn't beam or have breakup modes and integrates well with a horn and compression driver. The same goes for the extremely large format horns, it isn't really necessary, compression driver output is more than sufficient and and high efficiency with modern SS amps covers any need for power. You are really only trying to control the dispersion pattern.
Of course this is all opinion and each has their own.
So very true. Except for real PA sound systems and the very rare diy builder the days of large diameter speakers has come to an end. I know some here are convinced you need a very large diaphragm sized cone driver and very low excursion to get clear low frequencies that is far from real, many myths to this. The myth of doppler shift from a moving cone is the biggest one driving this need for large cones. In DBLT the doppler shift from a moving cone is not detectable. Some also just have nostalgia for these systems we grew up with, it really is mostly that. A smaller cone size solves so many problems for those trying to limit the number of crossover points without all the gyrations to find that magic speaker that doesn't beam or have breakup modes and integrates well with a horn and compression driver. The same goes for the extremely large format horns, it isn't really necessary, compression driver output is more than sufficient and and high efficiency with modern SS amps covers any need for power. You are really only trying to control the dispersion pattern.
Of course this is all opinion and each has their own.
Kindhornman, I sent it to consideration to Bill at GPA. I've bought re-cone kits from him in the past. I doubt he will bite, as he promotes the newer stuff as sounding better. Could be wrong though.
Actually, he may already offer it as a re-cone kit: from the website: "Full restoration for the original Altec 515 low frequency loudspeaker is available. This includes a full paper cone, phenolic spider, and total remagnetization." http://www.greatplainsaudio.com/service.html
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Kindhorman
I'd fall in that big cone aficionados group. Yes there are wonderful small cone 8" or less woofers but they aint sound the same as 15" , they just don't even with SS amps. The same with compression drivers. Usually the small ones are not as seductive
The reason why Japanese guys can haul huge JBL, Tannoy speakers in their tiny houses is simply because they can ,which cannot be said of 90% of North American guys who would not be allowed to do such thing in the land of Freedom ..
I'd fall in that big cone aficionados group. Yes there are wonderful small cone 8" or less woofers but they aint sound the same as 15" , they just don't even with SS amps. The same with compression drivers. Usually the small ones are not as seductive
The reason why Japanese guys can haul huge JBL, Tannoy speakers in their tiny houses is simply because they can ,which cannot be said of 90% of North American guys who would not be allowed to do such thing in the land of Freedom ..
