norman bates said:
A typical waterfall doesn't have the resolution to see anything. Typically you see 25-30 dB of vertical scale. To even come close to what (i guess) Mark is doing* you would need 2-3 times that rez. That is probably an impractically large anechoic chamber as a pre-requiste in your measuring kit.
*(laser interferometry (like B&W) or microflown (Geddes mentioned this euro tech))
dave
Hi Karl,
Yes it does. The resonance pattern changes as it travels along the cone's surface. Resonance is influenced by the size, profile (shape), mass and suspension of the cone. Also, the mass and connective method of the coil influences the cone's emitting properties. Being able to observe the physical properties of a cone under load conditions at the micro level is very useful.
The main reason for having accurate micro-measurement of the resonance pattern from many points on the cones surface, is we can close-control the production of this component. I've developed a new Computer Numerically Controlled (CNC) tooling system for the production of metal alloy cones, named Multi-Form-Mass-Reflex (MFMR). I've developed this technology with support, design and manufacturing input from Japan. Sounds posh but in engineering terms, its important. The tooling allows us to control the thickness of the cone on any part of its profile as its being made. The relationship between the cone's mass and its ability to flex is more predictable with this method of production.
Most cone production today involves some work by hand, especially metal alloy cones. Hand assisted forming can lead to wide variations in the cone's mass and shape. Making these components using MFMR delivers closer tolerance accuracy, repeatable for large scale production. This helps to reduce variations between drivers. It also contributes to the production of reliable publicised test data.
I've also started to apply some of the techniques to paper cones. There are significant differences in the production method, but close control technology is being applied and like metal alloys, we can observe the resonance properties from any changes we make the cone's design
MFMR also affords us the opportunity to extend the cones resonance range. Will this lead to metal alloy cones sounding more like paper? This aspect is hard to predict as the "human" element is relatively immeasurable. One audiophile's idea of a good sound is another's opinion of the same sound being bad. All the same, extending a cone's ability to emit over a wider range is useful. This feature offers end-users increased performance from a single point source. The tooling is now complete for 71-mm and 128-mm cones. The results can be seen in the Alpair 7 and 12 models.
Hope this helps,
Cheers,
Mark.
Yes it does. The resonance pattern changes as it travels along the cone's surface. Resonance is influenced by the size, profile (shape), mass and suspension of the cone. Also, the mass and connective method of the coil influences the cone's emitting properties. Being able to observe the physical properties of a cone under load conditions at the micro level is very useful.
The main reason for having accurate micro-measurement of the resonance pattern from many points on the cones surface, is we can close-control the production of this component. I've developed a new Computer Numerically Controlled (CNC) tooling system for the production of metal alloy cones, named Multi-Form-Mass-Reflex (MFMR). I've developed this technology with support, design and manufacturing input from Japan. Sounds posh but in engineering terms, its important. The tooling allows us to control the thickness of the cone on any part of its profile as its being made. The relationship between the cone's mass and its ability to flex is more predictable with this method of production.
Most cone production today involves some work by hand, especially metal alloy cones. Hand assisted forming can lead to wide variations in the cone's mass and shape. Making these components using MFMR delivers closer tolerance accuracy, repeatable for large scale production. This helps to reduce variations between drivers. It also contributes to the production of reliable publicised test data.
I've also started to apply some of the techniques to paper cones. There are significant differences in the production method, but close control technology is being applied and like metal alloys, we can observe the resonance properties from any changes we make the cone's design
MFMR also affords us the opportunity to extend the cones resonance range. Will this lead to metal alloy cones sounding more like paper? This aspect is hard to predict as the "human" element is relatively immeasurable. One audiophile's idea of a good sound is another's opinion of the same sound being bad. All the same, extending a cone's ability to emit over a wider range is useful. This feature offers end-users increased performance from a single point source. The tooling is now complete for 71-mm and 128-mm cones. The results can be seen in the Alpair 7 and 12 models.
Hope this helps,
Cheers,
Mark.
I heard the titanium diaphragm omnidirectional DDD from German Physiks and I find it better than any paper cone fullranger I know (and I know a few). Especially no metal sound at all. Unfortunately I can´t say much about other metal cone fullrangers, I only heard the little Jordan as midrange in an LCY speaker.
Threadjacking:
Must the DDD be so expensive?
I can imagine bringing titanium foil in such a steep cone shape can´t be done by simply pressing a flat foil. But why is the further handling a "pains taking process", as stated on the German Physiks website? Isn´t the driver build very much like a conventional one in terms of spider and surround?
Oliver
Threadjacking:
Must the DDD be so expensive?
I can imagine bringing titanium foil in such a steep cone shape can´t be done by simply pressing a flat foil. But why is the further handling a "pains taking process", as stated on the German Physiks website? Isn´t the driver build very much like a conventional one in terms of spider and surround?
Oliver
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Joined 2009
Paid Member
This is a very interesting thread, as I'm quite interested in trying the metal cone Alpair drivers after having already used Fostex drivers.
Forgive me if my question is actually a bit off-topic, but following up on the points made about the optimization of the cone - I saw a Fostex driver that have specially shaped cones, with radiating grooves/ridges on them. I haven't seen metal cones with these features, they all seem to be smooth.
Is this because of the differences between paper and metal cones ?
Forgive me if my question is actually a bit off-topic, but following up on the points made about the optimization of the cone - I saw a Fostex driver that have specially shaped cones, with radiating grooves/ridges on them. I haven't seen metal cones with these features, they all seem to be smooth.
Is this because of the differences between paper and metal cones ?
Bigun said:
I do have.
http://www.thielaudio.com/THIEL_Site05/Pages/models/Current_Models/CS3_7/cs3_7intro.html
Bigun said:
Mark Fenlon could probably provide the keenest insights into the complexities of mass production of metal cone drivers to which we're likely to have direct access. Don't be surprised however, if he invokes some proprietary circumspection.
As with paper, Kevlar, Carbon Fiber, or plutonium nano-tubes
, not all metal cones are engineered for the same purpose, as a quick visit to your local "high performance" car audio emporium would demonstrate.I (last night) replaced one of my FE103e's in small backhorn of my own design with an Alpair 6.
I hooked them up to a Sony HT receiver to compare quickly so do not know how they will fare on tubes or Tripath.
I have heard metal coned drivers before but it was a long time ago and the only thing I remember was that I was not impressed.
The Alpairs are a different kettle of fish to those I heard then.
These things are smooth and not "brittle" sounding at all.
Keeping in mind that I am one of the greatest proponents of the FE103's and while it is still very early, I think the FE103 may have at least met its match seeing that the Alpairs were literally "out of the box"
Thats how I felt as of last night anyway.
I still need to put more hours on the FE103's and tune the enclosure but I was very impressed with the Alpairs. They open a window into the sound and let you hear the sublety in a recording like the Fostex but without the rising response of the Fostex. They also seem cleaner, I think because of the lack of reflection through the cone. They certainly sound different to the Fostex, the Fostex somewhat drawing attention to itself while the Alpair just plays so smoothly and cleanly.
Anyways, during the next few weeks hopefully I will get around to more work with them but I like them a lot.
I hooked them up to a Sony HT receiver to compare quickly so do not know how they will fare on tubes or Tripath.
I have heard metal coned drivers before but it was a long time ago and the only thing I remember was that I was not impressed.
The Alpairs are a different kettle of fish to those I heard then.
These things are smooth and not "brittle" sounding at all.
Keeping in mind that I am one of the greatest proponents of the FE103's and while it is still very early, I think the FE103 may have at least met its match seeing that the Alpairs were literally "out of the box"
Thats how I felt as of last night anyway.
I still need to put more hours on the FE103's and tune the enclosure but I was very impressed with the Alpairs. They open a window into the sound and let you hear the sublety in a recording like the Fostex but without the rising response of the Fostex. They also seem cleaner, I think because of the lack of reflection through the cone. They certainly sound different to the Fostex, the Fostex somewhat drawing attention to itself while the Alpair just plays so smoothly and cleanly.
Anyways, during the next few weeks hopefully I will get around to more work with them but I like them a lot.
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Joined 2009
Paid Member
Hmm, I really like how those Thiel cones look. they must be very very stiff. I wish something like this was available to DIY market.
about paper and metal, IMO it doesn't really matter, all typically shaped cones are best used in narrow band, due to cone resonance.
If I was building full range system I'd look for driver with very deep cone profile, or one with ribbed cone. Since none of those available (with low inductance for full range use), the solution is DIY cone treatment (slicing, coating, replacing parts of a cone with different material, etc.)
about paper and metal, IMO it doesn't really matter, all typically shaped cones are best used in narrow band, due to cone resonance.
If I was building full range system I'd look for driver with very deep cone profile, or one with ribbed cone. Since none of those available (with low inductance for full range use), the solution is DIY cone treatment (slicing, coating, replacing parts of a cone with different material, etc.)
The little fullranger (sometimes called coaxial despite having only one voice coil) is also available, but only in combination with the woofer.
http://oaudio.de/Loudspeaker-chassis/Thiel-Audio:::127_59.html?XTCsid=0qupn7uct4dcao1pmfh4le95h5
There is a test of various small fullrangers in the current Hobby Hifi and I see the Thiel as the winner (closely followed by the Mark audio Alpair 6).
http://oaudio.de/Loudspeaker-chassis/Thiel-Audio:::127_59.html?XTCsid=0qupn7uct4dcao1pmfh4le95h5
There is a test of various small fullrangers in the current Hobby Hifi and I see the Thiel as the winner (closely followed by the Mark audio Alpair 6).
If I read the advert correctly, the Thiel coax you linked to are 699 Euros a piece, while the Alpair 6 have a llist price of $70 US. While it would be tempting to listen to a pair of the Thiels, the price of admission is certainly too rich for many of our budgets.
"Your pockets must be this deep to board this ride"
Like many others posting in this thread, I'm enjoying exploring a variety of designs for several models of Mark Audio drivers - at the prices noted above, most of the Alpair models can be acquired for less than the local sales taxes on the Thiels, or for that matter some of the other high end fullrange drivers from the likes of SEAS, PHY, et al.
"Your pockets must be this deep to board this ride"
Like many others posting in this thread, I'm enjoying exploring a variety of designs for several models of Mark Audio drivers - at the prices noted above, most of the Alpair models can be acquired for less than the local sales taxes on the Thiels, or for that matter some of the other high end fullrange drivers from the likes of SEAS, PHY, et al.
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