In a long stream of concept studies of mine, its time to explore a spherical sound emitting source. Inspired by ELS63 as well as my previous lines, I have decided to build a segmented bending wave line source. My hope and intent is that if I segment the line and time delay the segments (plates) it will fold from a cylindrical wave front (as from a tall, slim line source) to a spherical one.
The blue plates represent the synthesized wave front I'm anticipating....
I'm using parts from an old trial with one single long bending wave plate (total fail) and have cut it into 6 parts. I already took out 1 plate from them to be used in my bedroom so I'm lending that one for a sum of 7 plates for a speaker. This will require 4 individual channels (DA / amp) to time control the excursion of the plates.
I will use:
2 pcs of DAC with optical conection
1 RME digiface (USB -> Opto) to hook up the DACs
2 pcs of stereo amps.
A mac mini running CamillaDSP
Drawing:
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The blue plates represent the synthesized wave front I'm anticipating....
I'm using parts from an old trial with one single long bending wave plate (total fail) and have cut it into 6 parts. I already took out 1 plate from them to be used in my bedroom so I'm lending that one for a sum of 7 plates for a speaker. This will require 4 individual channels (DA / amp) to time control the excursion of the plates.
I will use:
2 pcs of DAC with optical conection
1 RME digiface (USB -> Opto) to hook up the DACs
2 pcs of stereo amps.
A mac mini running CamillaDSP
Drawing:
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There seem to be something wrong with the timing indicated above... 🙂 I'll think about it...
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Why does it need to be spherical?
If yes, could it be done by mechanical spacing instead of electronic steering?
If yes, could it be done by mechanical spacing instead of electronic steering?
The spherical wave front is the "holy grail" ;-)
Well, that would create a lot of diffraction between the spaced plats so it would probably be not so good.
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Well, that would create a lot of diffraction between the spaced plats so it would probably be not so good.
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Would be interesting if you can tell the difference in sound perception only with and without spherical time alignment🙂
Yes - that will be possible to explore by instantly switching between two configs in CDSP.
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But for sure...Why does it need to be spherical?
If yes, could it be done by mechanical spacing instead of electronic steering?
Bose 2201 ...
https://www.diyaudio.com/community/threads/jurassic-bose-the-bose-2201.276631/#post-4378572
I have in the plans to also build such shape/size but with plates and exciters...
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Would be interesting to see how you connect the plates together. Some silicone from cars where the plates can be put flexibly together?
Which exciters are affordable?
They should be cheaper than loudspeakers as they are smaller and need no cone.
Which exciters are affordable?
They should be cheaper than loudspeakers as they are smaller and need no cone.
I have no plan of connecting them together - but very close, say a mm or so. I want them to act separate in time so it's necessary to be separate.
I'm not up-to-date on exciters - these are from quite long time ago purchase and no longer available.
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I'm not up-to-date on exciters - these are from quite long time ago purchase and no longer available.
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System is up running. Initial measurements and adjustments made...
200Hz 4th HP... placed in corner.
Ch0 is the single middle plate. Ch1...Ch2 are the pairs more and more distant from the center - i.e. ch3 is on top+bottom of line source.

All ch run with and without delay - explains the a bit thinner sound of the delayed version...

Individual measurements after adjustment of gain. Quite equal I'd say...

EQed. Channels with same EQ applied (5 PEQ) + the summed, delayed.
RTA measurements made with pink noise and circling mic in listening position.
Sound... switching between the delayed and non delayed is different for sure. Delayed version sounds more focused yet a bit more distanced ... a bit softer... easier to listen to... just first impressions. The "thinner" impression is lessened after adjustments. Good impression with delay. Anyways, I'd really would like to listen to a pair 🙂
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200Hz 4th HP... placed in corner.
Ch0 is the single middle plate. Ch1...Ch2 are the pairs more and more distant from the center - i.e. ch3 is on top+bottom of line source.

All ch run with and without delay - explains the a bit thinner sound of the delayed version...

Individual measurements after adjustment of gain. Quite equal I'd say...

EQed. Channels with same EQ applied (5 PEQ) + the summed, delayed.
RTA measurements made with pink noise and circling mic in listening position.
Sound... switching between the delayed and non delayed is different for sure. Delayed version sounds more focused yet a bit more distanced ... a bit softer... easier to listen to... just first impressions. The "thinner" impression is lessened after adjustments. Good impression with delay. Anyways, I'd really would like to listen to a pair 🙂
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It is flattened to its best ability as per above. The bending plates don't play that deep - what you see is its natural ability which reaches down to about 400Hz. The rest need to be provided by other means. Conceptually it don't matter as below 400, everything will emitted will be spherical.
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I build spherical speakers using Ikea blanda matt bowls, made 4-sphere version with tweeter, mid, woofer and sub. 4 bowls stacked using a center pole and collars in between. But nothing like this, interesting project!
So if I understand it correctly, you have tried one long panel with time delayed exciters before and now you are trying separate panels?
Yes, I tried one continous long membrane with only one exciter... that didn't fly 🙂 It rattled and what not... I don't think I bothered to measure it.
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If you look at the measurements above, can you point to the problem that you are referring to?ТНТ
Your transmitter design will have problems with HF, namely interference mush.
HF requires a point radiator.
For "your" radiator to be a point radiator, you have to move a very long distance away from it.
Mr. Walker did quite OK with ESL63 - about the same principle. On axis it behaved well - I don't recall if I did any off axis measurements - need to check - but as these are bending wave transducers, directivity is very wide so I don't think it is a problem. Maybe I pick up on this again as snow goes away 🙂
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