This place has great plywood of exceptional quality.
FINNISH BIRCH AIRCRAFT PLYWOOD (METRIC) | Aircraft Spruce
FINNISH BIRCH AIRCRAFT PLYWOOD (METRIC) | Aircraft Spruce
IMO..
I always think of the pebble in the pond theory and if you look around, most all drivers are round. (Except for a few square subwoofers but they have a limited fidelity range and the harmonics created in the corners make them sound bigger)
There are other variations, such as 6x9, 6x8, 3x5, 4x10, ect. and none of them have corners. They all have a rounded contour with damping material on the outer edge. No driver that attempts to create a wide coverage of fidelity has corners. So, yes..
And.. Why are voice coils ALWAYS round..?
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Square drivers have issues with the corners of the suround having the same stiffness and excursion as the flat edges
Coils are easiest to make round.
Race track coil drivers exist that are not round
What I'm wondering is rounding corners on a big DML panel make a noticeable difference in sound? Has anyone tried with both square and round corners and tested it?
Coils are easiest to make round.
Race track coil drivers exist that are not round
What I'm wondering is rounding corners on a big DML panel make a noticeable difference in sound? Has anyone tried with both square and round corners and tested it?
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Mpte.
I notice that tectonic do not round the corners on their DML panels ?
Maybe because they XO before any bad vibrations are set up ?
Large panels will be more flexible than small panels when using the same materials ,if used full range with low frequencies the corners could become a problem.
That is when I would think the sound would become compromised ?
Will there be a subtle difference in the sound in the treble and midrange ? possibly ?
Steve.
I notice that tectonic do not round the corners on their DML panels ?
Maybe because they XO before any bad vibrations are set up ?
Large panels will be more flexible than small panels when using the same materials ,if used full range with low frequencies the corners could become a problem.
That is when I would think the sound would become compromised ?
Will there be a subtle difference in the sound in the treble and midrange ? possibly ?
Steve.
Mpte.
Something I did notice a couple of days ago, while cutting up one of my old card panels to match the basswood in size and shape.
I level matched the two panels close up by ear and deq, but when listening to music the card panel sounded thinner or lacking ?
So I was turning up the volume to correct the balance , but it still didn't sound correct ?
The only difference between the two panels apart from the materials was that the basswood had its long edge at the top and the card had the short edge at the top.
After remembering a comment my friend made (a couple of years ago now,have not seen him because of covid doesn't time fly ) about preferring the sound of his panels on their side,I turned the card panel on its side to match the basswood, and hay presto the imbalance was corrected.
Obviously turning a large panel on its side isn't going to be conviniant for everyone ,but I will probably at some time test this out just to see what happens?
I have noticed that pro panels seem to be mounted on their side,so now I think I know why ?
I think in one of the nxt patents they mention making panels 5% out of square, maybe in the future I will be doing this with a slight twist, we shall see ?
My microphone was picking up slight differences in response as were my ears , but nothing too drastic but all the same interesting.
Just thought I'd share this,in case it is of any use to anyone?
Turning the panel on its side is another freebie that could improve things ,maybe ?
Steve.
Something I did notice a couple of days ago, while cutting up one of my old card panels to match the basswood in size and shape.
I level matched the two panels close up by ear and deq, but when listening to music the card panel sounded thinner or lacking ?
So I was turning up the volume to correct the balance , but it still didn't sound correct ?
The only difference between the two panels apart from the materials was that the basswood had its long edge at the top and the card had the short edge at the top.
After remembering a comment my friend made (a couple of years ago now,have not seen him because of covid
doesn't time fly ) about preferring the sound of his panels on their side,I turned the card panel on its side to match the basswood, and hay presto the imbalance was corrected. Obviously turning a large panel on its side isn't going to be conviniant for everyone ,but I will probably at some time test this out just to see what happens?
I have noticed that pro panels seem to be mounted on their side,so now I think I know why ?
I think in one of the nxt patents they mention making panels 5% out of square, maybe in the future I will be doing this with a slight twist, we shall see ?
My microphone was picking up slight differences in response as were my ears , but nothing too drastic but all the same interesting.
Just thought I'd share this,in case it is of any use to anyone?
Turning the panel on its side is another freebie that could improve things ,maybe ?
Steve.
Attachments
rounding corners
It does not really matter on if you round or scallop the edges since it is only the longitudinal motion that generates sound.Transverse waves do not generate sound.There seems to be a lot of confusion in what waves generate sound. It like in the early days of nuclear physics where the electrons orbit the nucleus of the atom. It's a simple model but is wrong. For electromechanical sound generation it a piston motion that generates sound and not any transverse waves that are traveling on the surface. Sorry for the reality check but its physics
It does not really matter on if you round or scallop the edges since it is only the longitudinal motion that generates sound.Transverse waves do not generate sound.There seems to be a lot of confusion in what waves generate sound. It like in the early days of nuclear physics where the electrons orbit the nucleus of the atom. It's a simple model but is wrong. For electromechanical sound generation it a piston motion that generates sound and not any transverse waves that are traveling on the surface. Sorry for the reality check but its physics
Hi Tagis,
The corners here can make a difference because as the thread title is called Distributed Mode Loudspeaker (DML), and not pistonic mode loudspeaker. A sharp corner vs a 0.5in radius might not be too different, but a 3in radius probably will have an effect. This is because the traveling longitudinal waves is what makes the membrane vibrate. Even for traditional drivers in pistonic mode, when they go past pistonic mode and enter breakup mode, it is indeed the transverse modes that dominate the sound. That’s exactly how DMLs operate from the get go. If they were pistonic, they would act as a dipole but in fact act more like an Omni. So the best way to see this is to simulate it in FEA an look at the transverse modes and how shapes and corners affect it.
The corners here can make a difference because as the thread title is called Distributed Mode Loudspeaker (DML), and not pistonic mode loudspeaker. A sharp corner vs a 0.5in radius might not be too different, but a 3in radius probably will have an effect. This is because the traveling longitudinal waves is what makes the membrane vibrate. Even for traditional drivers in pistonic mode, when they go past pistonic mode and enter breakup mode, it is indeed the transverse modes that dominate the sound. That’s exactly how DMLs operate from the get go. If they were pistonic, they would act as a dipole but in fact act more like an Omni. So the best way to see this is to simulate it in FEA an look at the transverse modes and how shapes and corners affect it.
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I think what happens on a panel speaker ,was summed up quite well in this article.
Steve.
http://www.soundright.org.uk/NXTchaos.pdf
Steve.
http://www.soundright.org.uk/NXTchaos.pdf
A long time ago ,even before my time
We would be calling these panels sound boards, or sounding boards .
Which was so much easier to understand, I was going to say , before NXT re-invented the sound board as DML .
But DML just describes what happens on the panel and how to predict the performance with the software provided with the patent .
A musical box uses sound board ( dml ) technology, also the guitar,piano, violin and so on.
The sound board or DML is not a new idea in itself , but the idea that it could be used to build high fidelity sounding speaker using the software was very exciting.
But the software was very expensive and only for leasing with the patent ,I believe ?
So we have to use our ears and imagination to find the optimum sound from our panels.
I remember all the hype about NXT and the new technology.
If only they had built and produced a panel speaker themselves,that would have shown the world just how good they can be.
Although they would probably screwed that up too
Mainly now it has become regarded as a fun toy,and if mention to audiophiles ,you would be lucky if they just walked off in disgust.
Well, at least I know how good they are
Steve.
We would be calling these panels sound boards, or sounding boards .
Which was so much easier to understand, I was going to say , before NXT re-invented the sound board as DML .
But DML just describes what happens on the panel and how to predict the performance with the software provided with the patent .
A musical box uses sound board ( dml ) technology, also the guitar,piano, violin and so on.
The sound board or DML is not a new idea in itself , but the idea that it could be used to build high fidelity sounding speaker using the software was very exciting.
But the software was very expensive and only for leasing with the patent ,I believe ?
So we have to use our ears and imagination to find the optimum sound from our panels.
I remember all the hype about NXT and the new technology.
If only they had built and produced a panel speaker themselves,that would have shown the world just how good they can be.
Although they would probably screwed that up too
Mainly now it has become regarded as a fun toy,and if mention to audiophiles ,you would be lucky if they just walked off in disgust.
Well, at least I know how good they are
Steve.
where can I get exciters? PE is out of stock...
I like to get several exciters to test with my D-amp. I have ordered thru PE but they are out of stock. Anyone know where I can get them, perhaps other electronic stores on internet?, don't need to be high quality, but like to experiment ...
I like to get several exciters to test with my D-amp. I have ordered thru PE but they are out of stock. Anyone know where I can get them, perhaps other electronic stores on internet?, don't need to be high quality, but like to experiment ...
Xrk971.
He made his Stradivarius to sound beautiful, the problem for us is we are trying to make a panel sound like every type of instrument in the world .
And to reproduce them perfectly and accurately.
I'm constantly surprised and impressed by how good a panel can sound, and how close to the real sounds they can reproduce.
Steve.
He made his Stradivarius to sound beautiful, the problem for us is we are trying to make a panel sound like every type of instrument in the world .
And to reproduce them perfectly and accurately.
I'm constantly surprised and impressed by how good a panel can sound, and how close to the real sounds they can reproduce.
Steve.
