La Folia planar - Bipole radiation

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Gentleman,

Popular La Folia planar ribbon speaker can be set to dipole or bipole radiation. I couldn't find any thoughts on bipole mode. I mean plastic membrane can be attached to both sides of neo magnets rows so one can connect them as dipole push pull or bipole. The latter behaves like infinite baffle because two membranes are close to each other. Am I right it will make more bass? Do I need tweeter for La Folia?


And one more thing is SPL. My simulation for 10 um thick Mylar and Alu, 60x40cm panel, 0.3T tells me 81dB SPL. Am I right?
 
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jzagaja said:

Am I right it will make more bass?



Not sure you will gain anything but a better impedance...I also have concerns about the small amount of air trapped between the 2 membranes

It may need a bigger box, but then goes the good idea to have both "planars" driven by common set of magnets
I believe the problem with the use of planars fore bass or midbass is the big movement of the membrane

long time ago I build several version of the LaFolia...the best woofer was a true ribbon, only fastened at top and bottom and loose at the sides...man could it move, without any hint of "drumskin effect"
the urge is still there, and now we can get neo magnets ;) I think I would build a "slim" midrange planar and use multiple ordinary woofers fore bass, but expencive....at the moment 2 pairs of tweeter ribbon in the works.
 
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jzagaja said:

How does the true ribbon woofer looks like?


Sorry cant show picture, its long gone by now :cannotbe:

But I can tell you it was about 500mm wide and 1.2meter long/high...well, a little less wide at the top like Apogee, but if thats important I dont know
There was a tweeter at the side as well, just like Apogee
Membrane was corrugated
You know, when OleTofte made the first LaFolia he simply read the Apogee patent
I also made a version with the membrane fastened at the sides only, using thin foam "surround"...it was good too, but not as sweet in the mids as the "true ribbon" one
 
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Sorry, I deleted that omni thing

A big version of the raal would probably make a good 2way...implementation of woofers could be problematic though

Advantage would be higher sensitivity and impedance...and MAYBE it could be used a bit lower than a single "standard" ribbon...expencive experiment though

Well, it does look sweet...and then think of one MUCH bigger :cool:
 

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tinitus said:
Sorry, I deleted that omni thing

A big version of the raal would probably make a good 2way...implementation of woofers could be problematic though

Advantage would be higher sensitivity and impedance...and MAYBE it could be used a bit lower than a single "standard" ribbon...expencive experiment though

Well, it does look sweet...and then think of one MUCH bigger :cool:


Tinitus,

Any more pics or info on your "Cylinder " ............


Regards,
 
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