Yes, you're right. (and, what a perspective! )
In addition, it's very interesting to find the sticks are vibrating with the signal, while the excitors stay still, almost dead still by touching feel.
The 'pivot' of the stick at the bottom is also vibrating, but I can't make sure if this is the stick itself, or transmitted from the frame (indirectly from panel) -- the whole supporting frame is vibrating along the music and I haven't done anything to it, yet.
And this spring is connecting magnet of excitor and the panel on its both ends. I was thinking, should I add some more mass to the excitors? So I can have a bigger 'hammer', and then the panel would be kicked furthur away (larger excursion, higher SPL)
But the small excitors are dead still already! I don't get it.
Oh, this won't show up in any audio show. It's just a personal toy
Hi fellas,
I was following this with great interest, a year and a half ago. My brother in law and I built a set of these and were disapointed with output level and crappy highs. I know there were a lot of ideas thrown around about fixing the highs, but we tried something simple that helped imensly. I have a pair of bose 901's, and tried the equalizer. What a difference! Still not great ,but a step forward. Again, this is not my profession so the tech talk is often above my head, but maybe this helps move this project forward.
I was following this with great interest, a year and a half ago. My brother in law and I built a set of these and were disapointed with output level and crappy highs. I know there were a lot of ideas thrown around about fixing the highs, but we tried something simple that helped imensly. I have a pair of bose 901's, and tried the equalizer. What a difference! Still not great ,but a step forward. Again, this is not my profession so the tech talk is often above my head, but maybe this helps move this project forward.
Hi jzagaja,
the tip of finger is very sensitive to small movements
this is the way I found the 1/3-2/3 placement....
POL
Even on high frequencies
Professional way (despite vibrometer and mic array) is:
Scan & Paint - Products - Microflown
Professional way (despite vibrometer and mic array) is:
Scan & Paint - Products - Microflown
Hi,
the exciter actually is an accelerometer, by closer evaluation of the
impedance at a certain driving point ... more usable at lower
frequencies of course.
Cheers
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Emo Labs or Edge Motion Technology
I looked at the first thread. Its author excited the edge of a membrane with piezo drivers; to make a loudspeaker. There is an existing flat panel technology called Edge Motion by Emo Labs. Search Bing for Emolabs. Scroll down to the heading. Hear that; Boston... The U tube video shows the CEO or equivalent of Emo Labs demonstrating this new tech speaker.
I looked at the first thread. Its author excited the edge of a membrane with piezo drivers; to make a loudspeaker. There is an existing flat panel technology called Edge Motion by Emo Labs. Search Bing for Emolabs. Scroll down to the heading. Hear that; Boston... The U tube video shows the CEO or equivalent of Emo Labs demonstrating this new tech speaker.
Exciter: cheapo from PE is good enough for both experiments and mid or even long term using (depends on how you use them, of course)
Panel: feel free to experiement for yourself. Think light and stiff first, then do whatever you want/can for stiffening and damping. Go big.
It'd be an easy start, then you'll get confused, frustrated, excited again... Eventually, it's really hard to get perfectly right (like everything else).
Fun? no doubt!
Panel: feel free to experiement for yourself. Think light and stiff first, then do whatever you want/can for stiffening and damping. Go big.
It'd be an easy start, then you'll get confused, frustrated, excited again... Eventually, it's really hard to get perfectly right (like everything else).
Fun? no doubt!
hello all !
I have made some promising tests with a set of fresh DML on very big panels,
2 x 2.1m x 1.25m, (not enough place to keep with my usual tri-stereo setting.)
when using more than one driver on a panel, comes the question of "where should I set them?",not too close, not too far, not too even, not too random...
for single driver setting my best choice was at 1/3-2/3, in order to get a 1/4 wave in one direction and an 1/2 wave in the opposite side.
keeping in mind that we want to spread resonances of the panel, I set the 4 DML in a 1/2 , 2/3 , 3/5 , 5/7 sequence in both directions vert. & horiz. at 1/2H-5/7V, 3/5H-2/3V, 2/3H-3/5V, 5/7H-1/2V...
POL
I have made some promising tests with a set of fresh DML on very big panels,
2 x 2.1m x 1.25m, (not enough place to keep with my usual tri-stereo setting.)
when using more than one driver on a panel, comes the question of "where should I set them?",not too close, not too far, not too even, not too random...
for single driver setting my best choice was at 1/3-2/3, in order to get a 1/4 wave in one direction and an 1/2 wave in the opposite side.
keeping in mind that we want to spread resonances of the panel, I set the 4 DML in a 1/2 , 2/3 , 3/5 , 5/7 sequence in both directions vert. & horiz. at 1/2H-5/7V, 3/5H-2/3V, 2/3H-3/5V, 5/7H-1/2V...
POL
Hi POL,
Glad to meet you here
The 1/3-2/3 positions you mentioned are based on a flat rectangular panel, right? (or at least roughly a rectangular shape)
If the shape gets more complex, the vibrating modes are getting complex, too. At least for higher frequencies with shorter wavelengths. And if there are some reinforcing ribs / frames ... etc., things change further. Do you agree?
I'm planning on a curvy surface panel with a 'spine', and maybe some additional tricks on the drivers...
Glad to meet you here
The 1/3-2/3 positions you mentioned are based on a flat rectangular panel, right? (or at least roughly a rectangular shape)
If the shape gets more complex, the vibrating modes are getting complex, too. At least for higher frequencies with shorter wavelengths. And if there are some reinforcing ribs / frames ... etc., things change further. Do you agree?
I'm planning on a curvy surface panel with a 'spine', and maybe some additional tricks on the drivers...
I had built Beratgni type panel couple of years ago with limited success.
I used Styrofoam panel and a driver unit with the diaphragm+ voice coil assembly stuck into the panel..It was really exciting for a first build..but I want to try a refined build once again
Hi there,
My recent work:
A piece of 3mm thick foamcore board, 180 cm by 90 cm overall, with a curvy spine on its back.
The rear side:
The 'spine' for 5 drivers:
(the rear surface is brushed with diluted PVA glue, that stiffens the paper significantly)
With drivers installed:
With frames for hanging:
(top/bottom wood bars are sticked with the panel by 2 layers of double side adhesive tapes - the type with thick soft foam)
The front view:
It's there on floor during the works, now it's hung above the TV. This DML board plays the central channel in a linear matrix 3-channel system. You might see in the pic for other part of the system - dipole array midrange and slot loaded OB bass units.
My recent work:
A piece of 3mm thick foamcore board, 180 cm by 90 cm overall, with a curvy spine on its back.
The rear side:
The 'spine' for 5 drivers:
(the rear surface is brushed with diluted PVA glue, that stiffens the paper significantly)
With drivers installed:
With frames for hanging:
(top/bottom wood bars are sticked with the panel by 2 layers of double side adhesive tapes - the type with thick soft foam)
The front view:
It's there on floor during the works, now it's hung above the TV. This DML board plays the central channel in a linear matrix 3-channel system. You might see in the pic for other part of the system - dipole array midrange and slot loaded OB bass units.
I know the whole point of most people's NXT experiments have been to build truly full range and usable panels but has anyone tried a 2 way?
Apart from ceiling panels for background music, There are only a handful of successful commercially available large panels that pass as proper hifi. The rest of the time you see NXT panels commercially available is with smallish panels and a subwoofer(TDK, Mission, Wharfedale Pioneer etc)
I was thinking a smaller panel(say 300mm x 750mm ish) mounted in a 350mm x 1200mm high 'frame' with either smallish woofers in each(think martin-logan style) or just that panel on its own running 100hz and up with a subwoofer or 2? I think a 350 x 1200 black cloth and veneer panel(black cloth hiding eps foam exciter panel) with 2-4 exiters each in a 5.1 system would look very nice and should sound good with some experimentation.
Running active would gain some headroom for the exciters too?
This allows smaller panels and some WAF(few people including myself can have 2400 x 1200 panels in the loungeroom haha!)
I know it is not the 'point' of these excercises, but I'm figuring if these major manufacturs with mega R&D capability have found this to be the 'best' implementation of the technology, maybe its worth a look?
Apart from ceiling panels for background music, There are only a handful of successful commercially available large panels that pass as proper hifi. The rest of the time you see NXT panels commercially available is with smallish panels and a subwoofer(TDK, Mission, Wharfedale Pioneer etc)
I was thinking a smaller panel(say 300mm x 750mm ish) mounted in a 350mm x 1200mm high 'frame' with either smallish woofers in each(think martin-logan style) or just that panel on its own running 100hz and up with a subwoofer or 2? I think a 350 x 1200 black cloth and veneer panel(black cloth hiding eps foam exciter panel) with 2-4 exiters each in a 5.1 system would look very nice and should sound good with some experimentation.
Running active would gain some headroom for the exciters too?
This allows smaller panels and some WAF(few people including myself can have 2400 x 1200 panels in the loungeroom haha!)
I know it is not the 'point' of these excercises, but I'm figuring if these major manufacturs with mega R&D capability have found this to be the 'best' implementation of the technology, maybe its worth a look?
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