I thought i share my tinkering with DIY planar magnetics for a change

[Joppe Peelen]

Well i revisited a novelty weird planar i made as a test a 180 degree curved one. i am not to shure yet if i like it (180 is to much i think with this radius). it needs EQ and is not as flat as a regular flat one. (i need eq to get things.... flatter)
And by the standards here it might be rubbish (people are always rather harsh) .. i myself like planar sound and especially since i make things all myself, with is allot of fun. so dont ask me for spinorama measurements etc...

the goal was to make a tweeter that can be crossed rather low (600hz range) that is planar magnetic but with good dispersion, something that is rarely a thing. if it has good dispersion its only horizontal, or vertical... in this case given the low frequency it can reach, its performs rather well when i move the audio recorder. in the new video or in the old video where i use binaural mics. i linked to the music, if you want to hear me talking for an hour watch the whole thing. but i cant imagine !

use headphones, for the binaural, and prefered for the normal XY recording to.. since my room adds allot of low end thats not there when i listen to the video and so does yours (+ the room its recorded in, been 180 degree even more then normal) , its more a show and tell on the dispersion

Last video

Old video

 

[olieb]

Well i revisited a novelty weird planar i made as a test a 180 degree curved one.

Great stuff, really amazing!
For those like me who want to know more about the construction here is the first building video of the series.

 

[Joppe Peelen]

thanks, yeah i was not sure if people where interested in the building but there is another 300 videos about making planars if one wants to binge me making things that sometimes work... sometimes do not haha

 

[mhardy6647]

Well i revisited a novelty weird planar i made as a test a 180 degree curved one. i am not to shure yet if i like it (180 is to much i think with this radius). it needs EQ and is not as flat as a regular flat one. (i need eq to get things.... flatter)
And by the standards here it might be rubbish (people are always rather harsh) .. i myself like planar sound and especially since i make things all myself, with is allot of fun. so dont ask me for spinorama measurements etc...

the goal was to make a tweeter that can be crossed rather low (600hz range) that is planar magnetic but with good dispersion, something that is rarely a thing. if it has good dispersion its only horizontal, or vertical... in this case given the low frequency it can reach, its performs rather well when i move the audio recorder. in the new video or in the old video where i use binaural mics. i linked to the music, if you want to hear me talking for an hour watch the whole thing. but i cant imagine !

use headphones, for the binaural, and prefered for the normal XY recording to.. since my room adds allot of low end thats not there when i listen to the video and so does yours (+ the room its recorded in, been 180 degree even more then normal) , its more a show and tell on the dispersion

Last video

Old video

Sort of reminds me of the once-popular Lineaum tweeters, which were also used (in a cheaper OEM version) by Radio Shack for a while in the 1990s.

source: https://www.radioshackcatalogs.com/flipbook/1996_radioshack_catalog.html
Also reminds me of the curved electrostatic drivers used, e.g., by Philco in the US in the 1950s in some radio models.

Straight from eBAY to you!

(albeit curved the other way)

 

[Joppe Peelen]

well the Lineaum are completely different beast, i did made a few on my channel, although i called them Rubbanoids (if you want to see some builds of those). witch is an incorrect name indeed. Then the french guy called them the Janus. then some HIGH end fuckers ran with his design... asking 30K for a speaker. costing maybe 600 euro on materials...

the ESL i never seen but they look a bit like the B&W used on there insane nice looking speaker the DM70 (although much less high) love the looks of those!!. problem with these and probably with the one you posted is its not segmented. making the vertical dispersion terrible if i would make something like these i would add segmentation side ways. making the vertical also better for there size ! or if they dont care for vertical, there would be no need to curve them to achieve good dispersion.


by the way cool looking tech straight of ebay !! love that retro design and grill. !

 

[olieb]

Sort of reminds me of the once-popular Lineaum tweeters, which were also used (in a cheaper OEM version) by Radio Shack for a while in the 1990s.

A 360° ribbon was made by Elac. That is quite close, but smaller and therefore crossed higher.

 

[mhardy6647]

^^^ didn't know of that driver! Thanks.

 

[goryu]

The tweeter used in Gallo Acoustics is a 360deg dispersion as well-

 

[Joppe Peelen]

A 360° ribbon was made by Elac. That is quite close, but smaller and therefore crossed higher.

yeah i know that one, i once tried it, but a normal ribbon is quite hard... since gravity does not work along so i guess this ribbon is also held by the top and bottom in some way the cool thing is they can use a simple magnetic disc, to make the motor.

 

[Joppe Peelen]

The tweeter used in Gallo Acoustics is a 360deg dispersion as well-

yeah i wonder. since 360.... gives trouble.. it means on the opposite side things are 180 degree out of phase... even if this is not a problem it will be at the wavelength that correspond with the distance front to back... creating peaks and dips if the damping cannot absorb all of it.

my guess its only really high freq. so maybe it can who knows

but it wont work for something that wants to play low as well as high ! wavelengths get bigger and ignore the damping.

this one might be able to play 4khz to 20khz while this contraption in the video plays from 600hz to 18khz more or less.

 

[goryu]

yeah i wonder. since 360.... gives trouble.. it means on the opposite side things are 180 degree out of phase... even if this is not a problem it will be at the wavelength that correspond with the distance front to back... creating peaks and dips if the damping cannot absorb all of it.

my guess its only really high freq. so maybe it can who knows

but it wont work for something that wants to play low as well as high ! wavelengths get bigger and ignore the damping.

this one might be able to play 4khz to 20khz while this contraption in the video plays from 600hz to 18khz more or less.

I have a pair of Gallo Solos with this ribbon tweeter. They are quite nice speakers...

 

[Joppe Peelen]

I have a pair of Gallo Solos with this ribbon tweeter. They are quite nice speakers...

Yeah they are indeed Nice! Also i do not know how there tweeter is built, whats in the inside etc, so the above troubles might not be a thing for there way of design.

 

[olieb]

yeah i wonder. since 360.... gives trouble.. it means on the opposite side things are 180 degree out of phase... even if this is not a problem it will be at the wavelength that correspond with the distance front to back... creating peaks and dips if the damping cannot absorb all of it.

my guess its only really high freq. so maybe it can who knows

but it wont work for something that wants to play low as well as high ! wavelengths get bigger and ignore the damping.

this one might be able to play 4khz to 20khz while this contraption in the video plays from 600hz to 18khz more or less.

I did not know Gallo.
These guys look otherworldly.

Cool designs but I wonder how the directivity pattern over the whole range would play out.
Gallo has moved on to a somewhat restricted dispersion as it seems. And this only for treble.

One moment, please...

The Elac seems not to play mids either. But the funny hat (and a ring magnet?) is probably there to absorb some resonances, so maybe it goes lower than the Gallo.

 

[olieb]

yeah i know that one, i once tried it, but a normal ribbon is quite hard... since gravity does not work along so i guess this ribbon is also held by the top and bottom in some way the cool thing is they can use a simple magnetic disc, to make the motor.

I am not an expert on ribbon construction at all. A "normal" ribbon would not be held at the edges in some way?

 

[Alex_Brouwer]

Cool project, vanavond je youtube kanaal is doorspitten

 

[Joppe Peelen]

Cool project, vanavond je youtube kanaal is doorspitten

Ah je hoeft me dus geen berichtje te sturen zie dat je van hier komt haha

 

[Joppe Peelen]

I am not an expert on ribbon construction at all. A "normal" ribbon would not be held at the edges in some way?

normally not indeed, but people miss use the name ribbon for everything that has a flat coil in there case it seems to be a true ribbon not a planar magnetic but a piece of foil will not stay like this due to gravity, so it would droop downwards if its not held in place in some way. most long ribbons are supported as well at some places or else it will flop around with every breeze , destroying the thing foil. or it will flap around in the magnetic gap.

 

[Alex_Brouwer]

Ah je hoeft me dus geen berichtje te sturen zie dat je van hier komt haha

Correct nog niet zo lang lid hier maar nog nooit in zon korte tijd zoveel van geluid geleerd als hier hahaha

 

[D!sco]

I just wanted to say how much I love watching your work. It’s mad scientist, kind of silly, very open and thoughtful. It’s always exciting to see what will happen next.

Have you considered a partial sphere, like a half dome for wider output?

Would you ever make a curved “CBT” planar, and could it be suspended between the magnets without flapping?

 

[Joppe Peelen]

I just wanted to say how much I love watching your work. It’s mad scientist, kind of silly, very open and thoughtful. It’s always exciting to see what will happen next.

Have you considered a partial sphere, like a half dome for wider output?

Would you ever make a curved “CBT” planar, and could it be suspended between the magnets without flapping?

thank you ! well there is one here

for a Curved CBT ribbon not held by the sides. the shading or attenuation of the 8 parts of the ribbon are done by the magnetic field itself. on its own the ribbon will rest on metal bars (with foam) but if i inject a tiny voltage, i can make the ribbon curve like a segment of a cicle (shown in one of the CBT videos, i called it biasing) so this is a 80 cm long ribbon that acts like a point source. (more or less)

downside of this whole ordeal is efficiency, its already low with these magnets if the magnet is closeby, in CBT form thats even lower but it was an interesting test/design


i can also make this with the same tech used in the tweeter of this thead with rubber(very low efficiency) or with neos, slightly more efficient. or use 8 seperate coils. you can then use a curve, or use 8 delays and shading to make a flat CBT, wont be making that one. since i do not have that many DSP channels and amps