Hello,
I just read the Article in Audioxpress about building a flat Panel Speaker using the new Sonic Impact SoundPad exciter.
They only cost 20-30 USD a pair and you can just glue them on Foam Core Posterboard sized 20 x 30 inches 3/16" width for around 5 USD.
This is very interesting and very cheap but eh output is very low.
Does anybody where I can find a simulation software for free?
I know that there is an "NXT Designer" Software from NXT but you dont get that unless you have a liscence.
The Problem is that output is very low and I have seen that you can use multiple exciters pro Board to get a larger output.
4 Exciters per board would give 6 dB Raise in output Probably at the same impendance. The placement though is critical so you need to make tests or just know where to stick the exciters.
If anybody has done experiments or can help please post.
Many Greetings
Promitheus
I just read the Article in Audioxpress about building a flat Panel Speaker using the new Sonic Impact SoundPad exciter.
They only cost 20-30 USD a pair and you can just glue them on Foam Core Posterboard sized 20 x 30 inches 3/16" width for around 5 USD.
This is very interesting and very cheap but eh output is very low.
Does anybody where I can find a simulation software for free?
I know that there is an "NXT Designer" Software from NXT but you dont get that unless you have a liscence.
The Problem is that output is very low and I have seen that you can use multiple exciters pro Board to get a larger output.
4 Exciters per board would give 6 dB Raise in output Probably at the same impendance. The placement though is critical so you need to make tests or just know where to stick the exciters.
If anybody has done experiments or can help please post.
Many Greetings
Promitheus
I saw the same article (but didn't buy the mag.)
It has got me on to looking at the flat panels again.
Most interesting site I saw for these products was
slab audio:
www.slabsound.com
Also the Soundvu is some sort of flat panel screen
for sound and glare reduction on computer screens.
That is sure a novel idea.
Now could we think of a media for transmission
besides styrofoam? Styrofoam in all its varieties
gives me the willys.
It has got me on to looking at the flat panels again.
Most interesting site I saw for these products was
slab audio:
www.slabsound.com
Also the Soundvu is some sort of flat panel screen
for sound and glare reduction on computer screens.
That is sure a novel idea.
Now could we think of a media for transmission
besides styrofoam? Styrofoam in all its varieties
gives me the willys.
I just saw the same article as well. It looks pretty interesting. Could be a fun experiment for $40 or so. The off-axial response is really interesting... it seems almost perfect for home theater back and middle channels. Actually it might solve a problem I've been having about with trying to install a 5.1 rig in a very small space.
As for multiple exciters it sounds like it should work. Unless there is some creepy mojo with minor signal variations etc. I worry a bit because I imagine these things aren't terribly well matched to each other.
I'm searching for a simulator as well... but with no luck. I doubt we will find anything until some MathCAD wiz with accurate measuring equipment gets a bee in his bonnet to reverse engineer them. It seems to me that the problem is that there isn't a lot of real technical data freely available (at least from my 20 minutes of googling or so). And, if I understand it correctly, most of the calculations we normally use have to radically revised to work with a non-pistonic system. (Though I could be wrong on that)
The only solid data out there seems to be different versions of this lovely piece of marketing/theory: http://www.vxm.com/NXT.html .
Anyway, I won't have time to work on this for a while myself, but I sincerely hope a few people here start some serious work on these because I think that the tech has great possibilities for unusual audio situations.
As for multiple exciters it sounds like it should work. Unless there is some creepy mojo with minor signal variations etc. I worry a bit because I imagine these things aren't terribly well matched to each other.
I'm searching for a simulator as well... but with no luck. I doubt we will find anything until some MathCAD wiz with accurate measuring equipment gets a bee in his bonnet to reverse engineer them. It seems to me that the problem is that there isn't a lot of real technical data freely available (at least from my 20 minutes of googling or so). And, if I understand it correctly, most of the calculations we normally use have to radically revised to work with a non-pistonic system. (Though I could be wrong on that)
The only solid data out there seems to be different versions of this lovely piece of marketing/theory: http://www.vxm.com/NXT.html .
Anyway, I won't have time to work on this for a while myself, but I sincerely hope a few people here start some serious work on these because I think that the tech has great possibilities for unusual audio situations.
why not....
use one of those Aura one inch drivers to drive a film diaphragm? Fix a plastic film diaphragm to a frame and make a support to hold the driver up to the diaphragm from behind and glue the front edge of the inverted cone to the diaphragm then simply melt out the film covering the cone. A single point source will be a lot easier to work with than multiple drivers.
I can't see any way that a diyer is going to be able to calculate where to place multiple drive points and have them all work together. Millions was spent to figure that one out by NXT and a good guess is not going to get you there. With a single drive point you will still have your hands full figuring out how to damp the diaphragm into control, but it can be done. I speak from experience having spent the best part of a million dollars doing more or less the same thing with the Sumo speaker in the late 80's. Controlling diaphragm resonant modes with one point source of drive was a task to be sure but infinately easier than with multiole points of drive. I think that the Highwood Audio speaker (Sumo) worked as well if not better than the NXT versions as we got usable bass extension down to the mid 30 Hz. range with zero crossovers and only one driver. Regards Moray James.
PS: I would suggest that you target for panel response down to about 60-70 Hz. and cross over to a dipole sub to do the bottem end. Your life will be a lot easier that way as most all the nasty panel resonanses will not be excited so you won't have to deal with them. Have fun.
use one of those Aura one inch drivers to drive a film diaphragm? Fix a plastic film diaphragm to a frame and make a support to hold the driver up to the diaphragm from behind and glue the front edge of the inverted cone to the diaphragm then simply melt out the film covering the cone. A single point source will be a lot easier to work with than multiple drivers.
I can't see any way that a diyer is going to be able to calculate where to place multiple drive points and have them all work together. Millions was spent to figure that one out by NXT and a good guess is not going to get you there. With a single drive point you will still have your hands full figuring out how to damp the diaphragm into control, but it can be done. I speak from experience having spent the best part of a million dollars doing more or less the same thing with the Sumo speaker in the late 80's. Controlling diaphragm resonant modes with one point source of drive was a task to be sure but infinately easier than with multiole points of drive. I think that the Highwood Audio speaker (Sumo) worked as well if not better than the NXT versions as we got usable bass extension down to the mid 30 Hz. range with zero crossovers and only one driver. Regards Moray James.
PS: I would suggest that you target for panel response down to about 60-70 Hz. and cross over to a dipole sub to do the bottem end. Your life will be a lot easier that way as most all the nasty panel resonanses will not be excited so you won't have to deal with them. Have fun.
I've done a lot of messing around with homemade NXT style panels. I don't suggest getting involved in such a project if you have even the smallest hope that they will sound good. Even the sound of units made professionally are less than listenable.
Its a neat technology to play with, but in my opinion its nothing more than a novelty.
BTW, foam board like you find at a hobby/art store is by far one of the worst panel materials I tried. Thick corrugated cardboard was one of the better. HF response s*cks no matter what you use.
Its a neat technology to play with, but in my opinion its nothing more than a novelty.
BTW, foam board like you find at a hobby/art store is by far one of the worst panel materials I tried. Thick corrugated cardboard was one of the better. HF response s*cks no matter what you use.
Marvin,
How NXT designer works? Can for example define laminate, an orthotropic material? With any decent FEM simulator you can ran modal analysis in the far field - it's a typical task for acoustic classes. You should also be able to balance membrane and use traveling wave and membrane discontinuity to radiate the sound and extend the bandwidth.
How NXT designer works? Can for example define laminate, an orthotropic material? With any decent FEM simulator you can ran modal analysis in the far field - it's a typical task for acoustic classes. You should also be able to balance membrane and use traveling wave and membrane discontinuity to radiate the sound and extend the bandwidth.
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