I have stopped using mylar too noisy and too thin. Use 100 um poly now, don't use resistors for the impedance any more either. Let it be what it is is my new moto! Using the epsilon type layout as well. Use 50 x 12.7 x 3 mm neos touching each other NSNSNS etc. Will be experimenting with new diaphragm material easier to get taut. Plenty more rebuilds to do! My planars are all full range and don't use crossovers,or separate diaphragms. The bass is lower and tighter than the Quad ESL's. I have both the 57 and 63's. I also use ferrite magnets 50 x 25 x 10 mm, 50 x 22 x 10 mm, 50 x 18 x 10 mm and others half the thickness. I have also built epsilon layout using 50 x 12.7 x 6 mm neos, you have to be very careful with these, very strong and dangerous!! Would never use any thicker ones myself too dangerous, some person lost the end of his finger with 10 mm thick ones so be very careful and slide them apart. Best of luck in your endeavours.
im my opinion planar is the best in the low octaves, esl rule above. hence why a combination of both is a good start. magnepans work great in the low end, although could use some tweaking like push pull motor design. the new neos are nice but are still incredible costly compared the way magnpean uses rubber magnet. a magnepan holds in bulk prices no more then 20 euro in magnets. try that with neo''s its an incredible simple and cost efective design. its genius
In my experience too the Magneplaners have better lows or at least more of it then ESL's
I still like to find out what is the most effective magnet/conductor layout, the maggies are different then Jamesboss ( apogee) design.
As far as I understand the apogee forces act partly sideways on the membrane where the magnepan's fores act perpendicular to the membrane.
Then there is a lot more weight in the apogees conductor, so less efficiency.
I believe Jamesboss gets more sound pressure out his design then maggie but that isn't a fair comparison since he uses much more and much stronger magnets.
So I wonder, a maggie design with high power magnets in push pull configuration or the apogee design? Then, are high power maggie style magnets available?
I don't mind spending a few bucks for this stuff but don't like to buy thousand magnets to find out that I need another shape of magnets....
I still like to find out what is the most effective magnet/conductor layout, the maggies are different then Jamesboss ( apogee) design.
As far as I understand the apogee forces act partly sideways on the membrane where the magnepan's fores act perpendicular to the membrane.
Then there is a lot more weight in the apogees conductor, so less efficiency.
I believe Jamesboss gets more sound pressure out his design then maggie but that isn't a fair comparison since he uses much more and much stronger magnets.
So I wonder, a maggie design with high power magnets in push pull configuration or the apogee design? Then, are high power maggie style magnets available?
I don't mind spending a few bucks for this stuff but don't like to buy thousand magnets to find out that I need another shape of magnets....
I did build a pair using plastic magnets 3 mm thick, one of them sounded loud but the other one didn't, don't know what happened.I use the epsilon type layout as well, which is what the magnepan uses. You can buy any size of magnets you want, magnet size is not a problem. You can follow the magnepan layout with neos, ferrites or plastic ones, the main problem is the diaphragm material, stopped using thin mylar, and thick poly using a completely different material now, I have seen the light after 10 years of trials and tribulations. Under the weather at this moment of time so don't feel like building at the moment. Age is catching up with me.
Well, the difference in masses is not that much. What kind of moving masses do you think there are? The Apogee driver has more excursion. Magneplanar drivers need to be larger for the same kind of bass delivery.
If you use stronger magnets, you will increase efficency but loose bass. Increasing the field strenth will kill the high Q necessary for bass reproduction. A friend of mine built overkill Magneplanar drivers but was very surpriced by the lack of bass... Baffles were about 1.2 x 2 m.
You can build high effiency push-pull drivers for frequencies above circa 150-200 Hz.
Hi Henry,
First off all, get well soon!
I am not familiar with the term epsilon layout, looking at your layout it seems the same as apogee but differs from what I have seen in Magnepan.
Magnepan conductors are in the space between the magnets while your and apogees conductors are overlapping the magnets.
The diaphragm material that is interesting too but I think heavier means less effective -sound pressure wise- and more difficulties with (very) high frequencies.
Anyway I see what I can find about that “Poly” you mention.
Regards
Edmund
First off all, get well soon!
I am not familiar with the term epsilon layout, looking at your layout it seems the same as apogee but differs from what I have seen in Magnepan.
Magnepan conductors are in the space between the magnets while your and apogees conductors are overlapping the magnets.
The diaphragm material that is interesting too but I think heavier means less effective -sound pressure wise- and more difficulties with (very) high frequencies.
Anyway I see what I can find about that “Poly” you mention.
Regards
Edmund
Did try spaces between magnets with metal magnets but too much trouble staying on perforated sheet. So didn't build any more. Tried push pull as well not happy with that either, so gave that up. Have been experimenting for the last 10 years. I have finally arrived at my ultimate design for bass middle and top and sensitivity and tensioning the diaphragm, using the epsilon type layout.
Listening to my latest design, at the moment size 16" x 12" sound as loud as a pair 4' x 2' using ferrites, this is my latest design and hopefully my last!!!
I don't know but I can imagine the Apogee diaphragm have twice the mass
of the magnepan's. Have the apogees more excursion if so, do you have figures and can you explain why that is the case?
Maybe, I have to check such details later on but right now I don't think I want anything like a high Q to suggest I get more bass while an high Q is more likely to give a less controlled bass and produce lows that are not present in the music signal.
That just might be good enough for me.
Edmund
Henry,
In the mean time I read a lot about all this and found out that you are right about using something other then Mylar.
I appreciate experience anybodies experience but also like to understand what is actually happening an why. Now I have seen a couple of very interesting things and one of my goals is to find the most effective solution in terms of weight of the membrane and the forces acting on it and the max amplitude, ESL or magnet.
A magnet system seems to be the winner here.
Now I search for a ultra thin both sided metalized ( Aluminium ) membrane.
Suggestions where to obtain that are highly appreciated!
What I have in mind is printing the conductor trace on the metal and etching away what I don't need.
Edmund
then you need a laminated foil, the most common foils are metalized and are only few microns thick , the resistance would be to high to be usefull.
a good source of film foil with thicker aluminium laminiate i did not found yet (in the range of 20 40 micron alu) , let me know if you have more luck
well if your are gone use them as dipole you need higher Q, to compesate bass rolloff. (or use massive EQ) i never hear anyone complain about magnepan bass, and or most electrostatic fullranges, that also uses high Q to extend there frequency response. especially magnepan. is sort of a a example of a woofer with not the biggest amount of controll hence higher Q. if you ever striped a menbrame from ma magnepan you will notice that with all the wires and glue its pretty heavy, and driven by a pretty weak magnet motor, and not even in push pull.
I don't.
Really? well let me be the first one then.
I don't know if I may say it but I heard the more expensive magnepans and in my opinion they have a very poor boomy slow uncontrolled bass.
Edmund
I want to do things a simple as possible but not simpler.
Full range? well I guess it depends on what one call full-range. Personally I don't find it practical to go low with a dipole. It simply cannot go low enough for my liking.
On the high, well I was hoping an ESL without step-up transformer could do the trick mid and high ( Elektrostaten Project 06 ), unfortunately Peter Scheulderman is passed away and I cannot find anything about his amp. So that basically rules out a one piece ESL for mid/high.
Same problem for a magnetic planar, IFAIK it is not possible to make a one piece full-range magnetic planar either. I do not consider 15kHz or so full range.
So my first target is a wide range LOUD magnetic planar that can go rather low which I intent to build in an enclosure for several reasons.
All suggestions to accomplish that are much appreciated, things to solve are
How to obtain a lightweight membrane with a suitable size aluminium conductor
( that can be etched to the shape I want )
How to make sure the conductor doesn't tear while tensioning the membrane.
Many dimensions depend on what size neo magnets are available, what dimensions of stator plates are available, how much percentage open space in the stators is possible and wanted.
What is the best magnet layout and what is exactly that epsilon layout and what advantage does that have above the much simpler zigzag magnepan layout?
As far as I understand an efficient layout would be ( top view)
###################stator
S N N S S N N S
N S S N N S S N
---- ---- ---- ---- ----conductor
with the conductor being the underlining.
Then, as you mentioned, some metalized foils have a metal thickness of a couple um.
Suppose the ( aluminium) conductor is 20 mm wide an has a length of 5 meter, what layer thickness are we aiming for if we want a static impedance of around 5 ohm?
Edmund
Suppose the ( aluminium) conductor is 20 mm wide an has a length of 5 meter, what layer thickness are we aiming for if we want a static impedance of around 5 ohm?
Edmund
Because you opt to chose a verry short length and verry wide wide track , incredible thin layer.
a conducter of 1mmx1mmx1000mm has a resistance of 0.0286 Ohm since you want 20 mm width you can devide it by 20 = 0,00143 Ohm a meter
i now can do 1 Ohm/0.00143 wich is something like 699.3 times thinner then 1 mm or just leave it as 0.00143 mm(or 1.43 micron) in the end its the same
well i probably have a verry weird method of calculating this but im pretty sure the end result is right.
i see some problems here one is power handling, the mm2 of this conductor is only 0.00143 * 20 mm = 0.0286 mm2 wich is sort of nothing, it will get hot pretty quick! and burn and fail
Second for 20 mm width you need a prety big magnet gap. the smaller it is the stronger it is. or the more money you trow at bigger magnets, thats also an option.
but i think the biggest drawback is reason 1 , having such thin layer is prone to failure.
can check the math ere if you like
Resistance Calculator -- EndMemo
###################stator
S N N S S N N S
N S S N N S S N
---- ---- ---- ---- ----conductor
are these stacked ? or why are they like this ? im not sure how it works and why there are 2 rows. and why are they doubled except the first and last?
single ended like magnepan ? conductor in between rows?
Edmund
Because you opt to chose a verry short length and verry wide wide track , incredible thin layer.
a conducter of 1mmx1mmx1000mm has a resistance of 0.0286 Ohm since you want 20 mm width you can devide it by 20 = 0,00143 Ohm a meter
i now can do 1 Ohm/0.00143 wich is something like 699.3 times thinner then 1 mm or just leave it as 0.00143 mm(or 1.43 micron) in the end its the same
well i probably have a verry weird method of calculating this but im pretty sure the end result is right.
i see some problems here one is power handling, the mm2 of this conductor is only 0.00143 * 20 mm = 0.0286 mm2 wich is sort of nothing, it will get hot pretty quick! and burn and fail
Second for 20 mm width you need a prety big magnet gap. the smaller it is the stronger it is. or the more money you trow at bigger magnets, thats also an option.
but i think the biggest drawback is reason 1 , having such thin layer is prone to failure.
can check the math ere if you like
Resistance Calculator -- EndMemo
###################stator
S N N S S N N S
N S S N N S S N
---- ---- ---- ---- ----conductor
are these stacked ? or why are they like this ? im not sure how it works and why there are 2 rows. and why are they doubled except the first and last?
single ended like magnepan ? conductor in between rows?
Last edited:
Suppose the ( aluminium) conductor is 20 mm wide an has a length of 5 meter, what layer thickness are we aiming for if we want a static impedance of around 5 ohm?
Edmund
Because you opt to chose a verry short length and verry wide wide track , incredible thin layer.
a conducter of 1mmx1mmx1000mm has a resistance of 0.0286 Ohm since you want 20 mm width you can devide it by 20 = 0,00143 Ohm a meter
i now can do 1 Ohm/0.00143 wich is something like 699.3 times thinner then 1 mm or just leave it as 0.00143 mm(or 1.43 micron) in the end its the same
well i probably have a verry weird method of calculating this but im pretty sure the end result is right.
I understand what you are doing and I came out about the same (1.6) with figures I found, I wondered if that would be right, so thanks for the conformation.
So there is another thing that somehow must be solved. Suggestions anyone?
Well if you look at my former post, you see that the gap between the magnets isn't so wide at all.
The 20mm wide conductor means: two magnets and a gap between them equals 20mm.
Depending on what size magnets are available and if they are powerful enough, there is some freedom but not a 10 fold or so.
Yes there is a problem, taking another conductor like titanium ( if that is available ?? )
would increase the resistance but then it probably get just as hot.
can check the math ere if you like
Resistance Calculator -- EndMemo
###################stator
S N N S S N N S
N S S N N S S N
---- ---- ---- ---- ----conductor
are these stacked ? or why are they like this ? im not sure how it works and why there are 2 rows. and why are they doubled except the first and last?
They aren't stacked. 1;2;3;4;5 etc are magnets.
[image]Magnets.pdf[/image]
I think with this layout, in combination with a wide conductor gives the strongest driving force for a given amount of magnets.
No just drawn one side for simplicity and I am lazy.
No, conductor overlapping magnet 1 gap1 and magnet 2 then a turn and the second conductor line covers magnet 3 gap3 and magnet4 and so on.
Whats next? devide the 20mm wide conductor into multiple parts and with more thickness and weight. I don't see any other solution at the moment.
Edmund
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