Summer Project - Replication of MBL loudspeaker 101mkII

Frequency graph 2

I have ran my first experiment. The graph shows the frequency response for a new sealing material. I will be doing a total of 5 experiments dealing with the sealing material and will update as soon as i measure it. The graph seems to extend well into 4khz, where as the previous model extended to 2khz.
 

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hermetical or not?

Hi Magnasanti
I'm still on design phase. The voice coil should be 2 inches, and the lamelas will be made of fiberglass.
The idea is not to make individual petals but a single piece of a curved sheet with vertical cuts to get the spherical form.
But I still haven't clear if the sound came out only by the lamelas, and then the sphere is not hermetical, or the lamelas must be sealed inside of the gaps to increase the sensibility.
Sorry if it sounds confussing, but my english is not that good..

Good looking results, the graphics seems promising.

I can't see the videos btw.
 
Karellan and A.wayne

Hello. Yes I am pleased with the graphs for being my first speaker and a difficult one at that. I could guide you on you unique rendition if need be. Yes the increased surface area should work out quite nicely if made correctly. The inside must be sealed from the outside to increase sensitivity and unwanted noise. Could you mail me some models? So that I can better understand your design? I will fix the video and update the link.
 
Some years back I picked up a copy of the Japanese magazine, 'Stereo Sound' from the mid 80s from a used book store and was surprised to learn that the radialstrahler design was available as far back the early 80s as the MBL 100 and subsequently the MBL 101. I attach some pics which show a copious use of copper on the lamellars before the advent of carbon fibre.
 

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Thanks Amci99,
Very interesting pictures I have not seen before. There is so much of a difference between these 101 and 101mkii it is amazing how mbl keeps on finding improvements! I have not updated since I am waiting on the new sealing material to arrive it had to be "special ordered" and will take 2 months for them to even begin to ship it.
 
more pics

Some years back I picked up a copy of the Japanese magazine, 'Stereo Sound' from the mid 80s from a used book store and was surprised to learn that the radialstrahler design was available as far back the early 80s as the MBL 100 and subsequently the MBL 101. I attach some pics which show a copious use of copper on the lamellars before the advent of carbon fibre.

yes, the radialstrahler are with us since a very long time...
I'ts interesting that the first model have the mid speaker under the mid bass unit...

I've also included some render images from this site: radialstrahler mbl 101e mkii 3d model
 

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Yes the render images are nice but you sadly cannot gather useful measurements from them. Karellen have you had time to listen to the mbl speakers? I am sure that they are simply attached to each other and the motor is on the bottom of both.
 
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Yes the render images are nice but you sadly cannot gather useful measurements from them. Karellen have you had time to listen to the mbl speakers? I am sure that they are simply attached to each other and the motor is on the bottom of both.

I bet you can; 3ds was fully compatible with autocad, so if you dowload the model, almost certainly you can open it on acad, and judging for the quality of the model the dimensions should be real.

but I just guessing ;)
 
damping, compliance and density

Damping, compliance, density...
The neoprene is quite good on the three.

If the neoprene and the leather doesn't work well as inter lamelas sealant and damper, I will like to try something more advanced (and expensive), the sorbothane Sorbothane Sheets - 12" square, 1/8" thick | Edmund Scientific that looks like the neoprene, but with much better damping and compliance.
the problem is that maybe is very slow on recovering the shape...

I suspect that it is the material used by Mbl.

by the way... I've never had the oportunity to listen to the mbl speakers
 
Yes I know very well the Sorbonne product. I know factually that mbl does not use this in the current 101mkii. You are welcome to try it and show me:rolleyes:. Sorbonne is also extremely heavy compared to other materials. The density is 1.28 g/cm cubed.
 
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