Sound is pressure variation. The movement in the air comes from the movement, the deformation of the surface in contact with it... we can see or fill the deformation or not.
Like the footsteps in the corridor or the cries of a child on the floor above? Do you think the concrete floors or brick walls vibrate in such a way that the air can move? Or the sounds of cars travelling on the street somewhere out of sight?
My preferred glue coating is pva.
Used with Ali foil this can considerably reduce panel self noise, but not always in a good way.
This will depend on materials used.
Will this make any difference on 3/4 inch ply I'm not sure.
But maybe on thinner lighter plys like my crate ply, it might work.
Steve.
He, he, my fellow countryman! How lovely!
But I only live here. 🙂
In any case, sound is energy, not merely a variation in pressure. It can be used as a weapon.
If you want to move beyond the standard cone design, then you need to abandon the idea of "pushing the air," as well as Henry Azima's incorrect interpretation of "bending waves." Regarding the drawing you posted, people can certainly create drawings...
Last edited:
Lekha,
Please don't tell Dave (@EarthTonesElectronics), he would be sad to learn that his PhD thesis was debunked by a mere painter.
Luckily, Lord Rayleigh has passed some time ago, so at least he will be spared any embarrassment.
I did enjoy the You Tube video with all the old horn speakers that you shared. Thanks for that.
Eric
Christian,
It seems Freedom 666 likes silicone adhesive.
Eric
Not everyone can be a good painter, let alone become a painting contractor!
I've heard that some PhD holders can't even change a simple light bulb. 😉
He has an entire wall singing, in addition to the floor!
And here's Part Express playing with boxes, vending machine walls, garbage bins etc.
Last edited:
I'm not sure I have a favorite, but I agree with Christian regarding thin poplar or other lightweight plywood. It is relatively light and stiff for decent efficiency, and has decent amount of internal damping to minimize ringing at resonance frequencies.
If you want something with more efficiency, then you could use XPS or EPS foam.
If you want to avoid ringing, use something with good internal damping, like PMMA (acrylic), but be prepared to be disappointed with its efficiency.
I suspect that the best material overall would be a composite with stiff skins and a lightweight core, but exactly what specifications I don't yet know!
Eric
Oh, that I agree with. I did not mean to disparage him, "merely" was your word.
Eric
Thank you Eric,Christian,
It seems Freedom 666 likes silicone adhesive.
Eric
I asked because I am in the idea aluminum is maybe not that easy to glue because of its oxide. I was thinking about neoprene glue (contact or impact glue maybe in English?)
Christian
And, another with Dayton exciters...
There is much more interesting content on his page.
Last edited:
If you are going to use very thick panels like these, it will probably be best to use the Aiyima exciters as they seem to me to drive the heavier panels better than the usual light coil exciters.
They seem to work more like a buzzer, vibrating the board harder, which the usual exciters have problems with.
On the other hand, The Aiyima exciters do not drive light panels very well.
I am surprised no one has mentioned these strange oddities with this type of exciter, it was the first thing I noticed.
Steve.
Hello Eric.Christian,
It seems Freedom 666 likes silicone adhesive.
Eric
Some time ago I coated a 5mm EPS panel with silicone and it wobbled like a jelly, and didn't stop wobbling.
Maybe a very thin coat under the Ali foil might be OK🤔
Depending on materials?
But I am a little dubious.
I'll stick(😃) with PVA.
Steve.
I think I might try the foil coating on one of my large crate ply panels.
They suffer from a lot of noise if not delt with.
I accidentally stepped on one of them the other day, so I will have to glue it back together again .
The foil will make it stronger.
But not stronger enough to withstand me standing on it 🫣
I use weights to adjust the frequency response and this reduces the self-noise also.
But it will be interesting to see if the foil reduces this also.
I am not expecting it to sort out the frequency response though.
Steve.
They suffer from a lot of noise if not delt with.
I accidentally stepped on one of them the other day, so I will have to glue it back together again .
The foil will make it stronger.
But not stronger enough to withstand me standing on it 🫣
I use weights to adjust the frequency response and this reduces the self-noise also.
But it will be interesting to see if the foil reduces this also.
I am not expecting it to sort out the frequency response though.
Steve.
@homeswinghome
alu foil on paper latest tests showed silicone sealant works pretty well
apply thinly on the tart alike cut pieces of foil and fix with fingers onto the cone
have a thread on it
how to make a sandwich cone
alu foil on paper latest tests showed silicone sealant works pretty well
apply thinly on the tart alike cut pieces of foil and fix with fingers onto the cone
have a thread on it
how to make a sandwich cone