diy fullrange ribbon

[ionomolo]

I have been interested in planars and ribbons since i first heard of maggies and i would like to build my own ribbon fullrange.

A bit of thinking leaves me with the conclusion that a fullrange loudspeaker could be build by using massively parallel small ribbons, as long as they have enough displacement to get the spl needed at the bottom. If the loudspeaker was big enough the emmited wave would be close to a plane wave and not fall significantly with distance.

I hadn't already thought what to use as ribbon, but the design would be arround 50x100 cm made by using parallel magnetic ribbon like that:

http://www.magnet-magnete.eu/elastis...lig-p-438.html

creating arround 50 gaps of 1 cm width with an horizontal magnetic field with the ribbons between.

what do you think? will be worth the effort of building?

Thanks

[a.wayne]

Are you building a full range Ribbon or planer magnetic ?

[ionomolo]

It's a fullrange ribbon, i like the ribbon idea because all the points should have the same acceleration (ideally) and thus there should be no elastic energy stored in the ribbon.

It should radiate as a planar because the massively-parallel ribbons are like a flat surface as long as the gaps between them are much shorter than a wavelength.

[a.wayne]

Hello ,
You will have issues controlling excursion on a fullrange ribbon , tension and diaphram material is very important , so is the corrugation for support .

I'm currently experimenting with one supported by the sides .......

[ionomolo]

My intention was to build one vertically supported with a soft material and high tension to make sure there is little horizontal elastic force to modulate the frequency response.

EDIT: the vertical force will be k(deltaY) where k is small and deltaY large, so the vertical force would be large, while the horizontal would be k(deltaY) and be small. If the wave does not fall as rapidly with distance as it does in point sources excursion might be small enough to be under control.

What do you think about it?

[tinitus]

Originally posted by ionomolo
My intention was to build one vertically supported

with a soft material and high tension to make sure there is little horizontal elastic force to modulate the frequency response.

What do you think about it?

Yes, vertically supported is the way to do it

But there is still risk of diaphragm "noise" and drumskin-effect
The corrugation that Wayne mentions cures some of that very effectively, but corrugation is really only possible if all the diaphragm is covered completely with foil, and thats the opposite what I want to try now

Fullrange?...I have done several 2ways with big bass planars, and tried all combinations
The first was supported only at top and bottom only, like a tweeter ribbon
Man, could that thing move
And within its limits it did sound best of all I made, very "free" and natural
Supported vertically only at the sides, with foam "surround" was ok too, and much more practical
Pure planar was the worst of all

Today i wouldnt use it below 100hz
So size will be mostly a matter of sensitivity
Still, its a genuine dipole, so dont expect heavy low end power
But my experience is from before there were any neo magnets, and neos have really triggered my interest again

[ionomolo]

Originally posted by tinitus



Yes, vertically supported is the way to do it

But there is still risk of diaphragm "noise" and drumskin-effect
The corrugation that Wayne mentions cures some of that very effectively, but corrugation is really only possible if all the diaphragm is covered completely with foil, and thats the opposite what I want to try now

Fullrange?...I have done several 2ways with big bass planars, and tried all combinations
The first was supported only at top and bottom only, like a tweeter ribbon
Man, could that thing move
And within its limits it did sound best of all I made, very "free" and natural
Supported vertically only at the sides, with foam "surround" was ok too, and much more practical
Pure planar was the worst of all

Today i wouldnt use it below 100hz
So size will be mostly a matter of sensitivity
Still, its a genuine dipole, so dont expect heavy low end power
But my experience is from before there were any neo magnets, and neos have really triggered my interest again

I should not expect too much low end power because of the interaction with the reflected wave?

[ionomolo]

Originally posted by tinitus



Yes, vertically supported is the way to do it

But there is still risk of diaphragm "noise" and drumskin-effect
The corrugation that Wayne mentions cures some of that very effectively, but corrugation is really only possible if all the diaphragm is covered completely with foil, and thats the opposite what I want to try now

Fullrange?...I have done several 2ways with big bass planars, and tried all combinations
The first was supported only at top and bottom only, like a tweeter ribbon
Man, could that thing move
And within its limits it did sound best of all I made, very "free" and natural
Supported vertically only at the sides, with foam "surround" was ok too, and much more practical
Pure planar was the worst of all

Today i wouldnt use it below 100hz
So size will be mostly a matter of sensitivity
Still, its a genuine dipole, so dont expect heavy low end power
But my experience is from before there were any neo magnets, and neos have really triggered my interest again

I should not expect too much low end power because of the interaction with the reflected wave?

[tinitus]

Planars are really not good at big movements(Xmax)
Its a nonlinear motion
Planar magnetsystem is weak in relation to a magnetgap on a dynamic woofer
Maybe a pushpull magnet design with greater gap would work, which means that no matter which way the diaphragm moves, it will always be getting closer to either side of the pushpull magnet plates
Question is whether that is linear motion

At the time I didnt know much about Q values, but I did sometimes experience better sound when using less magnets
I still dont know much about Q values in planars
But we do know that dipole bass, or even bass in general, tend to go deeper with higher Qts values
Why should it be different with planars
But it is contradicting, and with higher Qts values theres an unavoidable loss of control
In which case the dipole nature is kind of "helpfull" being a "no-boomer" by nature


At low SPL it obviously doesnt matter so much, but at higher SPL the diaphragm tend to get out of control and live its own life
Obviously diaphragn "noise" gets worse with greater motion
Diaphragm noise on planars should be taken really serious
And there are a few ways to deal with it
Corrugation is one, but not possible with true planars, that are fixed all way round
Different diaphragm materiels matter too
The film I used was fore cooking, and a bit stiff, and tended to rattle if not very careful...maybe even cheap soft plastic from a bag would have been better
But I have seen a diaphragn crumble completely because of the heat, so I used something that was made fore heat
But today I think I would try some softer materials
Foam at the sides could be another option, and there are several ways to do that
Even the glue used makes a differense

But used at its best it sure does sound like magic