Hi Oliver,
I couldn't tell any difference in the sound between the covered or uncovered, but being unable to hear any sound above 8khz, this probable has some effect on my listening.
The material used is just what I liked at the time, especially the holo fabric.
The only important criteria is the elasticity. Best is the 4 way stretch variety which makes it much easier to cover awkward sticky out bits! It makes for a nice smooth finish.
Using neo magnets is to be preferred' because of the lighter weight and higher sensitivity, although when I first started 20yrs ago neo's weren't available.
The only measurements I do is just listen as I have no measuring equipment.
I build off the top of my head, with what I have, usually old dismantled wardrobes etc. Wood is far too dear on top of the magnets,which I use in their thousands. Using old wardrobes makes covering them imperative. It hides all the mistakes etc.
I am going to build a p/p full range planar using neos, when I order the magnets from china, which are still cheaper even with large posting charge.
Henry.
I couldn't tell any difference in the sound between the covered or uncovered, but being unable to hear any sound above 8khz, this probable has some effect on my listening.
The material used is just what I liked at the time, especially the holo fabric.
The only important criteria is the elasticity. Best is the 4 way stretch variety which makes it much easier to cover awkward sticky out bits! It makes for a nice smooth finish.
Using neo magnets is to be preferred' because of the lighter weight and higher sensitivity, although when I first started 20yrs ago neo's weren't available.
The only measurements I do is just listen as I have no measuring equipment.
I build off the top of my head, with what I have, usually old dismantled wardrobes etc. Wood is far too dear on top of the magnets,which I use in their thousands. Using old wardrobes makes covering them imperative. It hides all the mistakes etc.
I am going to build a p/p full range planar using neos, when I order the magnets from china, which are still cheaper even with large posting charge.
Henry.
I'm rather sure, that you can't make an AMT work much lower than 1k ..... I'm not so sure exactly why that is, but it does have very different physics ...
But making membranes for an AMT is even harder than for a planar
There are no real problem to make a AMT that goes all the way down...
All AMT I have taken a closer look at are more or less a "blue copy" of the original patent..
Due to my AMTs are more than 1:10 or 10:1 different from standard AMTs the midrange runs flat down to 100Hz and fall in level below like any standard drivers.
One midrange AMT in a horn cabinet runs flat down to 60Hz.
The bass AMT are ready to be assembled and will hopefully play down to 20Hz...
The diaphragm for a AMT are no problem for a manufacturer with the needed tools / machines..
Hi RayCtech
Very interesting.
So what you are saying is that the "wave form"/"bends" are 10 times deeper on your design?
Show us some pictures ... please
Very, very interesting
Heil never did any such drivers himself. ESS made some bass mids actually very like the Tymphany LAT drives, which was run in open baffle ...
Baldin
Very interesting.
So what you are saying is that the "wave form"/"bends" are 10 times deeper on your design?
Show us some pictures ... please
Very, very interesting
Heil never did any such drivers himself. ESS made some bass mids actually very like the Tymphany LAT drives, which was run in open baffle ...
Baldin
Hi RayCtech
Very interesting.
So what you are saying is that the "wave form"/"bends" are 10 times deeper on your design?
Show us some pictures ... please
Very, very interesting
Heil never did any such drivers himself. ESS made some bass mids actually very like the Tymphany LAT drives, which was run in open baffle ...
Baldin
No, there are other properties than "wave form/bends" that are different and the cause of the performance.
I designed my own "AMT" driver in the 70ties before I discovered the patents of Heils works.
There are a lot of "faulty" informations regarding AMT that I have read during the decades that I expect are used as "facts".
One of these strange informations was that AMT diaphragms got very hot and could "burn"...
When I measure the diaphragm temperature at high SPL (110 dB) levels and DC to 100kHz bandwidth the temperature can possibly rise 0.5 to 1 degree celsius...
The cause of the temperature / burns (and the resulting high distortion) are simply shortings between folds of the diaphragms (in standard AMTs).
At higher SPL levels you may even be able to see the sparks this are causing..
Still think you should show us some pictures ......
You will find more information and pictures here:
http://www.diyaudio.com/forums/full-range/156466-one-only-full-range-amt.html
I have built 2 pairs of p/p full range planars using neo magnets, size of the finished speaker being 60 x 40 mm, I am very pleased with the outcome the bass is very good, deep and tight. This is my final design, and I am in the process of dismantling all the ones I have built over the last 20 years! This includes the ones using ferrites, which will be larger, because of the difference in magnet power. I have finally sorted out out the membrane mounting which was a large problem. All things came together with this design of a push pull nature. I am very pleased after years of development.
Planars
Jamesbos,
You appear to have 'arrived'. ;-) Size only 60mm X 40 mm ? And you are happy with the bass?
Perhaps you should post some pictures and details of the build, especially your 'tricks' with mounting the membrane, so that some of us can emulate your project and reap some satisfaction too! I am full of curiosity...
Congratulations--both for your success and your patience!!
Jamesbos,
You appear to have 'arrived'. ;-) Size only 60mm X 40 mm ? And you are happy with the bass?
Perhaps you should post some pictures and details of the build, especially your 'tricks' with mounting the membrane, so that some of us can emulate your project and reap some satisfaction too! I am full of curiosity...
Congratulations--both for your success and your patience!!
Planars
Jamesbos,
Sir, your enthusiasm and example should keep us 'boys' (57, here!) on our toes!
Yes, agreed that the size is 'normal'. So can we have the details as soon as you can organize some pictures and a description of the key techniques.
It is not only wine that gets better as it ages! Congrats again!
Jamesbos,
Sir, your enthusiasm and example should keep us 'boys' (57, here!) on our toes!
Yes, agreed that the size is 'normal'. So can we have the details as soon as you can organize some pictures and a description of the key techniques.
It is not only wine that gets better as it ages! Congrats again!
Thin foils
Don't know if this helps but Granger has many ALUM foils some of them quite thin. Here's a link but search under foil and you can find some different metals also. For reference ordinary copy paper is about 0.004
http://www.grainger.com/Grainger/wwg/search.shtml?op=search&N=15567&Ne=10071&in_dim_search=1
Don't know if this helps but Granger has many ALUM foils some of them quite thin. Here's a link but search under foil and you can find some different metals also. For reference ordinary copy paper is about 0.004
http://www.grainger.com/Grainger/wwg/search.shtml?op=search&N=15567&Ne=10071&in_dim_search=1
For my new planar i hawe made a downscaled version
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It is not curved but bend .
I will try a 1½ way ,only the center panel plays treble,but all mid/bass.
An externally hosted image should be here but it was not working when we last tested it.
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It is not curved but bend .
I will try a 1½ way ,only the center panel plays treble,but all mid/bass.
It sounds like the other one i made with 30 my folie.It has a peak at 200-300hz.
The resistance of 9,6meterlong 4,5mm wide is 2.2 ohm.center panel is made of 3mm.foil 4,8meter long and 1,6 ohm.
The efficiency is as the one made with only 3 rows of magnets and 7 my alufoil.
Do i increece sensivity by running 2 or more conductors.in the same "gap"
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The new one might call for a larger baffle size,
to make use of the larger membrane area at
low frequencies ....
I guess you want it to be narrow because of the
esthetics ?
Even an asymmetric baffle could improve the upper
bass towards being more balanced.
If modal behaviour of the membrane is an issue,
a dampening cloth behind the membrane could
tame it.
Kind Regards
to make use of the larger membrane area at
low frequencies ....
I guess you want it to be narrow because of the
esthetics ?
Even an asymmetric baffle could improve the upper
bass towards being more balanced.
If modal behaviour of the membrane is an issue,
a dampening cloth behind the membrane could
tame it.
Kind Regards
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Hi Båndsai
What are you using for diaphragm?
Mylar ... and what thickness?
What kind of sensitivity are you getting. Is it much less than say a normal midrange speaker?
As has been pointed out, you are not getting enough out of your magnets. You need either to move them closer together, or run more turns between them. You can go close to the middle of the magnets to get the maximal out.
I once made a small push pull, seaker using only 2 mm thick neo magnets, running 6 lines of conducter and having 3 rows of magnets, 50 cm high.
Think they where fine down to some 200 Hz and the sensitivity was comparable to a normal speaker.
With you big magnets, you should be able to get really good sensivity.
(the measurement was only made from 1k and up on the picture below)
Beat regards Baldin
What are you using for diaphragm?
Mylar ... and what thickness?
What kind of sensitivity are you getting. Is it much less than say a normal midrange speaker?
As has been pointed out, you are not getting enough out of your magnets. You need either to move them closer together, or run more turns between them. You can go close to the middle of the magnets to get the maximal out.
I once made a small push pull, seaker using only 2 mm thick neo magnets, running 6 lines of conducter and having 3 rows of magnets, 50 cm high.
Think they where fine down to some 200 Hz and the sensitivity was comparable to a normal speaker.
With you big magnets, you should be able to get really good sensivity.
(the measurement was only made from 1k and up on the picture below)
Beat regards Baldin
Attachments
Here are the responsecurves.The peak is at 500 -1000hz.I dont have a problem with sensivity,i was surpised that it was not more sensitiv than my other planars.
One of the curves are with a 47uf. across the outer panels.All panels are in series.
My next move must bee to make a diapram with 7 my alu.There is only 10mm gap betwine the magnets.I always try my speakers with a battery to see if the membrane moves syncrone.
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