Planar speaker - first try

[WrineX]

waht is you distance between magnet and menbrane if you go to 15 hetz, there's allot of air moved, do you have any pictures by the way >?

[JAMESBOS]

When I put the 4.5 mm alu foil on the membrane, I overlap the width of the cut out and turn the foil thro' 90 degrees then another 90 degrees until you travel in the opposite direction across your membrane. I mark the membrane between the magnets with indelible pen, and cover this with the tape, which is easier to turn than the 9 mm size.

[JAMESBOS]

The distance is 3 mm. I will be putting more pictures on the imgur sight later. Keeping the membrane nice and tight helps with the bass and cuts down on flapping etc. I won't be building any bigger neos than this size. the bigger size 1000 x 550 mm will be for my ferrite ones as I have many magnets available from downsizing. The gap on the ferrite ones will be 2 mm as these need help when compared with the neo magnets. When you put the magnets on slide them over the perforated steel sheet as they break too easily when dropping them on the sheet, also too dangerous on the fingers as I found out. (2 blood blisters and 2 gashes). A tight membrane all the way round is very important to get rid of funny noises when playing loud music with lots of bass!

[JAMESBOS]

With my planars you only need 3 resistors for the impedance, no capacitors,. inductors or transformers, and only 4 connectors to the 2 membranes

[JAMESBOS]

The size of the membrane is about 209 square inches which is quite large for any speaker, with p/p this is doubled!

[WrineX]

When looking at your specs i wonder hoe à maggie can even work with such low strength magnets.

[a.wayne]

Originally Posted by WrineX

When looking at your specs i wonder hoe à maggie can even work with such low strength magnets.

Pretty small gap.....

[bentl]

Hi Henry!

Any advice on how you thigthen the diaphragm?

[JAMESBOS]

I place the diaphragm in position under the 4 pieces of wood holding it in place. Mark the holes in the diaphragm with an awl , remove the wood then mark round the holes with a square and cut this out the diaphragm, so you can move it in any direction.Place the diaphragm roughly in position and hold with drawing pins at the corners. Place the wooden clamps in position and put a few screws in position. Pull diaphragm tight and tighten the screws in position. Then work your way around pulling the diaphragm tight until you have all the screws in position keep doing this until it is tight all round. Once you have a few screws in position you can remove the drawing pins. So you can complete the gradual tightening. you can see the diaphragm loosing its ripples as you go round loosening and tightening screws. You tap it with your fingers testing the tautness.

[JAMESBOS]

Have just finished the last planar of the second pair. The one with the 6 mm at the front and 3 mm at the back.This weighs in at 16 kilos. The one with 3 mm back and front weghs in at 12 kilos. Will hang this in place tomorrow.