Perhaps you thought my question was about the speaker in general, but what I was asking about was the details of the radiating membrane itself.
Maybe the plywood is part of the frame, and not the membrane?
Eric
That's enough for me. 🙂
Do they feel like omnidirectional at far field? Say, about 2-3m away from the speakers?
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Chdsl
Oh now I see.
I didn’t realize that the speaker shown in Alivpet’s video was the same as was described in the Herger patent.
Thanks
Eric
Good idea.
So basically, reversing the phase on one speaker will cancel the pistonic radiation and hopefully leave the dml or bendingwaves intact.
Nice one.
Steve.
I also thought so before this experience with comparative metering, but as you can see, the subtraction also occurs above the coincidence frequency, although not to such a large extent.
I suppose, Oliver Göbel also understood the Transverse Technology and implemented it in his own way, am I right? He may have a different name for that.
Thank you Alvipet.
The link is empty but with "PPD subs" I found your thread PPD subwoofer (Petrenko Petrushevsky's Dipole). I will switch to that thread for this topic.
Christian
Here is a interesting web page for those who are doing vibrating plates https://www.marksheinin.com/vibration
When talking about DML/bending wave/flat panel speakers, the term "transverse wave" is typically used to describe the wave in the membrane, not the wave in the air that is created by the transverse waves in the membrane. A bending wave is a transverse wave. Transverse simply means the displacements of the medium are perpendicular to the direction of travel of the wave. In a bending wave speaker, the waves travel in the plane of the membrane, but the membrane itself is being displaced in the direction perpendicular to the membrane.
So in the usual meaning of transverse wave, in the context of flat panel speakers, every dml/bending wave/panel speaker can be considered to be using transverse wave technology. NXT speakers, Goebel speakers, Tectonics, DPK and all the rest use transverse waves.
The Karavashkin paper looks interesting, and appears to refute a common understanding about how waves can travel in gasses. But what is it that makes you believe that the "transverse technology" referred to by the DPK Transverse Wave Technology, is referring to transverse waves in the air, rather than simply transverse waves in the membrane?
I didn't see anything in the Herger patent implying anything special about the wave it generates in the air. What is the link between the Karavashkin paper and the DPK speaker other than the use of the term "transverse"? I'm not saying there isn't one, just that the link isn't clear to me. For now I'm inclined to assume the DPK meaning of transverse wave is referring to the wave in the membrane.
Eric
Gas here is air. Karavashkin talks about waves travelling in gasses and in liquids. Remember, I mentioned few times, that as fish live in water, we live in air? Anyway, why not ask that question directly from @Alvipet? In the video in post #8,192 at 0.37 mins, you can see the DPK Sound logo on the speaker.
I'd be much happier to build a speaker type @Sandasnickaren had done, rather than Mescalitos or DPKs. 🙂 Thomas is much upfront with his creation.
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I asked you because you are the one that said to read the paper to understand Transverse wave technology. I had the impression he shared the link as a favor to you.
But I'd be very happy to hear from @Alvipet or others on the topic.
Eric
Yes, fish live in water and we live in air. Who would have thought? You keep repeating that, but never get much further. I thought you were going to explain before New Years Eve, but as expected, you petered off again, only to return with another round of 'Fish live in water, and we live in air, by gosh! 🤣
I haven't read the Karavashkin paper yet (link was blocked by my ISP), but my understanding is that 'transverse wave' is normally reserved for shear waves where the displacement is perpendicular to the panel, as distinct from bending waves where there is rotation involved. Could it be he means shear wave?
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Oh yes, I expected further questions about this) Therefore, I will give you a link to another resource of Karavashkin, with his own explanations