Blatthaler Speaker?

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kelticwizard

diyAudio Moderator Emeritus
Joined 2001
#1
Might have spelled it slightly wrong or left out an umlaut, lol. 🙂

I came across this term in an audio magazine some years ago. It is a planar speaker, an electromagnetic analog of an electrostatic.

I got the vague impression, from what I read of it, that it had a certain problem which is why it never became popular, and gave way to the ribbon speaker.

But that sketchy info is all I remember. Does anyone know more?
 
#4
kelticwizard said:


Do you know the operating principle?
Click to expand...


magnetostat?



http://64.233.179.104/translate_c?h...atthaller&hl=en&rls=GGLG,GGLG:2005-28,GGLG:en

other like this-

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An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


66
 
#6
Hmmm...

Blatthaler.

Something that goes BLATTttttt!!!
and haler, or "to call", "hail" or "holler"...

Looks like a field coil with an aluminum diaphragm.
Perhaps just a high output buzzer for military applications?
Or maybe a speaker.
The one on the stand that looked like it was cast iron or aluminum makes me think it is a high output device, so maybe a buzzer or signaling device for high noise environments.

I think I've read about them before, but I can not recall what it was.
🙁

_-_-bear
 
#7
Definitely a loudspeaker. If you translate the above link you can get a rough idea about how it worked.

“The Riegger Blatthaller is an electro-dynamic large surface loudspeaker, with which the attacking forces are practically evenly distributed over the diaphragm surface. The electric currents which can be shown are supplied Kupferleiter. The leader is riveted under span of insulants mäanderförmig on an aluminum diaphragm […]; the Kupferleiter dips into the field strong electromagnets […].

The sound-radiating Duraluminmembran possesses a strength of approximately 1/10 mm. After a suggestion of H. Gerdien will provide the diaphragm with a waving. Waving lies to the leader direction, one keeps so a outstanding effective reinforcement of the diaphragm perpendicular in relation to bending stresses. At the edges parallel to the leaders the diaphragm in felt or a similar flexible material is stored; at to the leaders the senkrechten the diaphragm is clamped edges, but is firmly ensured that the part of the diaphragm surface supernatant over the leader ends is so flexible in relation to bending stresses that the natural oscillation of the diaphragm lies underneath the frequency range important for the transmission. The Blatthaller represents thus a low-co-ordinated system. Since only a close edge zone implements bend oscillations, the system works similarly a piston diaphragm. “
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In that time also today still the giant Blatthaller for a capacity of 1000 Watts, standing there only in the world, developed. The press comments are interesting from time at that time. There was hardly a newspaper in in and Auslande, which would not have appreciated this technical large act. Even the merry sheets dedicated a whole title page to him. Into 20 kilometers periphery and depending upon the wind direction he was to be heard far beyond that. Its voice sounded over the Bodensee von Lindau to to the jenseitige bank after Rorschach. Its voice was so enormous that the police intervened, because church actions in the further environment were disturbed of Berlin. As at that time the Tonstreifen “west front” with Maschinengewehrgeknatter, garnet impacts and battle noise was notified, was shaking the result in the wahrsten sense of the word.”
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The large versions had a diaphragm made out of 1.5mm aluminum and had "oscillations" of 20mm.😱
 
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#8
bear said:
Hmmm...

Blatthaler.

Something that goes BLATTttttt!!!
_-_-bear
Click to expand...

Funny, that was my first impression when I saw the name as well. I saw a small piece in Audio magazine about them being planar speakers, full driven over the surface.

Being magnetic, at least they don't require a new diaphragm when you overdrive it and it goes Blatt! against the magnet. It just gives a distorted waveform.

They had some problems, I forget the details-or perhaps I didn't understand the details in the first place. Anyway, the article made clear that they gave way to ribbons for those seeking a magnetic equivalent to the electrostatic.

If I might hazard a guess, I would guess this. The Blatthaler had a thin, single strand winding inside it's diaphragm, and it reacted with a flat permanent or field coil magnet over the diaphragm's entire surface. There used to be single ended electrostatics, but there is the problem that on the outward stroke the force is less than on the inward stroke, (because the diaphragm is farther away from the electrode on the outward stroke), leading to a nonlinear waveform. So they developed the double sided electrostatic to correct that.

However, with the electrostatic, all you need is an aluminum sheet punched with holes over 50% of it's surface to let the sound out. Easy enough to do. With the Blatthaler, if you want to go double-sided, you would still need to let the sound escape out front, but this time it would be a magnet which would have to have holes occupying 50% of it's surface-and they would have to be real small holes like an electrostatic too. Otherwise you would get response irregularities.

Since most magnet materials are not particularly punch-pressable for even easily drillable, that would present some problems in construction. As a result, they either stuck with the single ended Blatthaler, complete with it's built in irregular waveform, or moved onto the ribbon.

That is my guess. It is the best I can surmise.
 
#11
Ok,

following the links around...

It's an electrodynamic planar loudspeaker with a big **** field coil magnet.

There are a few variations. It is unclear if it has a wound voice coil in some implementations or if it uses just the single turn of aluminum - but always in a gap!!

Obviously they managed some serious Bl in that gap!!

NOT single ended.

_-_-bear
 
#12
Well, it it has gaps-by which I think you mean conventional voice coils, even with only turn of wire-then how do we square that with this excerpt from the original link?

The Riegger Blatthaller is an electro-dynamic large surface loudspeaker, with which the attacking forces are practically evenly distributed over the diaphragm surface.
Click to expand...

About the only thing I can think of is that the voice coils are tiny, and so numerous that they are spread over the whole surface of the diaphragm.

On the other hand, if that is the case, it would be single ended.

Hmmm......
 
#13
The keyword is "practically"... which in pre WWII terms is a fairly broad statement.

It does appear to use a single turn "voice coil" in one of the illustrations shown. But geting the original German patent would tell the whole story.

Poke around the site and follow the links listed in the above post from tomtt or the translated google page I posted... you'll find some diagrams.

It still unclear to me if they meant 100 acoustic watts - that seems unlikely in retrospect - so probably it was run off 100 watts, which at the time was a huge amount of audio power. Although they did have modulators for AM broadcast into the many many kilowatts at that time...

The idea that it was audible 20km away - albiet on a 400 ft tower, iirc, seems a tad "optimistic"... unless they hung a vertical array up there! 😀

Regardless, there have been many speakers made that use this basic principle since that time...it's a vc driving a planar surface. Electromagnets.

Not so difficult to replicate...

_-_-bear
 
#14
I could find this picture in a german forum:
 

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#18
Unfortunately I don't have the time for that but an interesting quote from the info about the giant Blathaller:

– Der Lautsprecher wird mit 120 Amp. Sprechstrom beschickt und seine Aluminium-Membrane macht Ausschläge von 20 Millimeter.
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"The Speaker is driven by 120 amperes of "voice current" (i.e. drive current in proper English) and its aluminium diapragm makes excursions of 20 mm."

I'd like to see that output transformer used for 120 Amperes !!!!!!!!! Also 20mm of excursion was quite a lot for many decades to come !

Regards

Charles
 
#20
phase_accurate said:
Unfortunately I don't have the time for that but an interesting quote from the info about the giant Blathaller:



"The Speaker is driven by 120 amperes of "voice current" (i.e. drive current in proper English) and its aluminium diapragm makes excursions of 20 mm."

I'd like to see that output transformer used for 120 Amperes !!!!!!!!! Also 20mm of excursion was quite a lot for many decades to come !

Regards

Charles
Click to expand...


Not a big deal... think low voltage output, high current, like welding... big step down. The VC on the one that "meanders" was likely a fraction of an ohm, like a real ribbon... it looks like it merely snaked its way through the gaps in a _-_-_ <--- zigzag.

_-_-bear
 
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