Michael if you go to post 424 you will get directions to 3 photos which will you enough imformation to build planars .Regards Henry
I had the same question I think David is asking: single ended or push-pull? Single ended in this context means the magnets are located only on one side of the diaphragm (usually behind it). Push pull versions have magnets both in front of and behind the diaphragm, the advantage being that the diaphragm moves within a symmetrical and more uniform magnetic field and therefore exhibits lower distortion.
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Sorry Michael, Go to tubes 3rd one down permanent photo gallery then page 59, then look at posts 1458, 1460, 1461 these show the magnet layout using ferrites, the aluminium tape on the plastic membrane and the finished speaker covered in speaker grill cloth. I think the magnets were 50 x 15 x 9mm. The layout is the same for the neos but they are smaller :-50 x 12.7 x 3mm. the neos are a lot stronger so the sensitivity is much higher. You can use the ferrites with a transistor amp and the neos with a valve amp, usually the transistor amp giving more power.Although I have driven all my full range planars with valve amps. My new neo designs are sensitive enough to be driven by about 9 watt valve amps. I have built 3 different designs of neo full range planars without crossover or transformers or midrange or bass cone add ons, my designs cover the full spectrum from 8hz to over 20,000hz. I have just ordered 2,400 neo magnets to finish one speaker size 4' x 2' x 3". I am also designing and building a 7' x 2' x3" monster pair using 1,920 neos. Should sound awesome with impedance about 6-8 ohms. So will be easy to drive. I have plenty of the ferrite magnets in stock if you require any. Regards Henry.
Thanx a lot!
Hello Henry,
now I see! Very interesting project and photographs. Gratulations!
If you're curious please have a look at my own homepage at http://www.michaelgaedtke.de/SubMenu_Lautsprecher/Ribbon_1.htm
Hello Henry,
now I see! Very interesting project and photographs. Gratulations!
If you're curious please have a look at my own homepage at http://www.michaelgaedtke.de/SubMenu_Lautsprecher/Ribbon_1.htm
Very interesting, but far too technical for my meagre expertise. I see you go in for heavy engineering. Those magnets look fairly dangerous could crush your fingers and tear flesh quite easily. I am afraid I have no technical background and only have basic equipment like a multimeter . I did buy a oscilloscope but I really don't know how to use it. Still I do most of my measuring by ear.
If it sounds good your there, that's my modus operandi, and it's always worked for me. I have been more than satisfied with all my projects up to now in the loudspeaker stakes.Regards Henry.
PS Your designs look very technical and full of heavy engineering.
If it sounds good your there, that's my modus operandi, and it's always worked for me. I have been more than satisfied with all my projects up to now in the loudspeaker stakes.Regards Henry.
PS Your designs look very technical and full of heavy engineering.
Well, sticking your fingers in the mains power supply is dangerous too, or even driving in the traffic 
🙂 well, I do have had a snap at my fingers from magnets like that and it did bleed
but its healed now
BUT actually I am more concerned about the nickel plating and I advise to wash hands every time you have handled those neo magnets...afterwards coffee, cigarettes or water has a funny taste
🙂 well, I do have had a snap at my fingers from magnets like that and it did bleed but its healed nowBUT actually I am more concerned about the nickel plating and I advise to wash hands every time you have handled those neo magnets...afterwards coffee, cigarettes or water has a funny taste
Isee now what you mean by se and p-p mine are SE. I should have thought that P-P would interfere with the sound on a full range planar. Magnets both sides of the diaphragm!! Never tried this myself but my gut feeling is that it would be worse than SE. As long as you suspend the diaphragm correctly a SE one would be OK.
Once made a 1m x 0.5m bass ribbon which was only supported at the sides, assisted by thin foam "surround"...it was completely free at bottom and top
At moderate level it sounded fantastic and absolutely free of the known "drumskin-effect"
Unfortunately at loud levels it was totally out of control
Today I would like to try a very tall and not so wide midbass ribbon...maybe about 10cm(5in) wide
unfortunately those neos makes it a bit expencive and further my future listening room will be a loft...no room fore tall speakers under the roof, unfortunately...but I will still make those small ribbons🙂
At moderate level it sounded fantastic and absolutely free of the known "drumskin-effect"
Unfortunately at loud levels it was totally out of control
Today I would like to try a very tall and not so wide midbass ribbon...maybe about 10cm(5in) wide
unfortunately those neos makes it a bit expencive and further my future listening room will be a loft...no room fore tall speakers under the roof, unfortunately...but I will still make those small ribbons🙂Hello Tinititus,
Whats the maximum height in your loft? I have built a pair of full range planars sized 21" x 24" x 3" I'm sure these would fit in your loft. These use about 500 neos 50 x 12.7 x 3mm for the pair. These are full range so you don't have to build anymore speakers or add other coned speakers for the bass. Just a thought, also these are very easy to build and not very heavy about 5 kgs. each. Regards Henry.
Whats the maximum height in your loft? I have built a pair of full range planars sized 21" x 24" x 3" I'm sure these would fit in your loft. These use about 500 neos 50 x 12.7 x 3mm for the pair. These are full range so you don't have to build anymore speakers or add other coned speakers for the bass. Just a thought, also these are very easy to build and not very heavy about 5 kgs. each. Regards Henry.
Jamesbos here , magnets arrived , started on the other 4' x 2 x 3" planar yesterday. Magnets in place 525. Only 2 blood blisters, this time. Cutting rubish bag today , mark position of magnets, then put the tape on plastic , hope to fit today with no tears fingers crossed, this is the hardest part you have to be very careful, rip the tape and you have to start again on the 74 rows .If all goes well will finish speaker in a couple of days!! Then I can listen to the pair using the Quad 11's I have just purchased .Plenty of sensitivity so will have plenty in reserve(watts). That's all for now Regards Henry.😀
Hi Henry,
I think I understand how you speakers are constructed. However, where are the wires connected to the foil?
cheers
Aidan
I think I understand how you speakers are constructed. However, where are the wires connected to the foil?
cheers
Aidan
Hi, Chalkandtalk,
You fix the foil with screw and washer, trap the foil under then use nut to tighten then another nut to hold ring termina for cable, have finished the other 4' x 2' x 3" to make a pair. Sound great and quite sensitive. Have started on my 61/2' x 21" large panel full ranger, just putting the magnets on. Should have all on today 910 on each panel. The harder part will be sticking the tape on without tearing it!! Shold sound great and be very sensitive, plenty of umphh in reserve. Regards Henry
You fix the foil with screw and washer, trap the foil under then use nut to tighten then another nut to hold ring termina for cable, have finished the other 4' x 2' x 3" to make a pair. Sound great and quite sensitive. Have started on my 61/2' x 21" large panel full ranger, just putting the magnets on. Should have all on today 910 on each panel. The harder part will be sticking the tape on without tearing it!! Shold sound great and be very sensitive, plenty of umphh in reserve. Regards Henry
Henry,
Do you connect one wire at the bottom and the other at the top of the aluminium sheet?
Also, do you glue the magnets to the metal sheet?
cheers
Aidan
Do you connect one wire at the bottom and the other at the top of the aluminium sheet?
Also, do you glue the magnets to the metal sheet?
cheers
Aidan
Hi,
It is not aluminium sheet, it is aluminium tape which you place on the membrane in one continous strip between the rows of magnets . Leave sufficient tape at each end so you can trap both ends under 2 washers held with 5mm screws, one at the top + and the other screw and washer at the bottom - impedance should be about 4 ohms if you build the 4' x 2' sized wooden surround, no need to glue the magnets. They stick like glue anyway on the perforated steel sheet. I am listening to my newly built 4' x 2' x 3" full rangers burning in my new chinese EL 34 B P/P Amp, just arrived today. Plenty of volume at the 4 ohms or 8 ohms setting. Also burning in the speakers as well. Well worth the trapped fingers and backache, the sound is so open and the bass is really tight. They are also very revealing so you need a good source and amp to drive them. Crap in and you certainly get crap out. Be very careful with the magnets they jump quite well and can trap the fingers. All the best Henry.
It is not aluminium sheet, it is aluminium tape which you place on the membrane in one continous strip between the rows of magnets . Leave sufficient tape at each end so you can trap both ends under 2 washers held with 5mm screws, one at the top + and the other screw and washer at the bottom - impedance should be about 4 ohms if you build the 4' x 2' sized wooden surround, no need to glue the magnets. They stick like glue anyway on the perforated steel sheet. I am listening to my newly built 4' x 2' x 3" full rangers burning in my new chinese EL 34 B P/P Amp, just arrived today. Plenty of volume at the 4 ohms or 8 ohms setting. Also burning in the speakers as well. Well worth the trapped fingers and backache, the sound is so open and the bass is really tight. They are also very revealing so you need a good source and amp to drive them. Crap in and you certainly get crap out. Be very careful with the magnets they jump quite well and can trap the fingers. All the best Henry.
Henry, this sounds such a simple idea I must give it a go.
Would an 8' by 1.25' give the same frequency response as a 4' by 2'?
The plan
3/4" MDF for the back; wooden frame; metal sheet glued to MDF;
magnets attached to metal sheet covering an area of 8' by 1'; plastic sheet - the sort used for damp course; 30 micron alu tape from CPC stuck to plastic sheet (I'm not quite sure how you arrange to get one continuous strip); sheet stretched over frame about 3mm from magets; Loudspeaker cloth to cover plastic sheet; connect wires; voila
Does this sound right?
Would an 8' by 1.25' give the same frequency response as a 4' by 2'?
The plan
3/4" MDF for the back; wooden frame; metal sheet glued to MDF;
magnets attached to metal sheet covering an area of 8' by 1'; plastic sheet - the sort used for damp course; 30 micron alu tape from CPC stuck to plastic sheet (I'm not quite sure how you arrange to get one continuous strip); sheet stretched over frame about 3mm from magets; Loudspeaker cloth to cover plastic sheet; connect wires; voila
Does this sound right?
Henry,
what size magnets are you using, and where do you buy them from?
Do the magnets cover the metal sheet completely?
what size magnets are you using, and where do you buy them from?
Do the magnets cover the metal sheet completely?
Hi, Chalkandtalk.Sounds about right although I don't glue perforated sheet to MDF. I screw it to frame. I use 50 x 12.7 x 3mm neos which you can get from www.supermagnete.de The more you buy the cheaper they are. The frequency response will be the same, but the sensitivity will be higher if you use more manets to fill the bigger cutout. You cut a hole in the MDF in the shape of a trapezoid, but you only put the mangets on top of the cutout. The tape is put across the gap between the magnets then you reverse the direction and follow the next join between the magnets, etc etc. Leaving enough at the ends to trap the ends of the tape under the screw and washers. Fixing the loudspeaker cable to the other side of the screw + and -. Just be very careful with the magnets and the tape which is easily torn. Regards Henry.