Hi Paul, yes the Dayton units are the same as the Sonic Impact types.
There is a lot of promise with the experiments so far, but trust me you won't need a box to reinforce the bass.
A large panel at home here has produced some surprisingly low rumbles(and that's a rough as guts cardboard panel not mounted in anything - just propped up with a balsa wood rod !!
Your assessment of the dots is agreed with as far as we know so far.
Keep us posted of your experiments with the Dayton exciters.
Cheers,
Rob.
There is a lot of promise with the experiments so far, but trust me you won't need a box to reinforce the bass.
A large panel at home here has produced some surprisingly low rumbles(and that's a rough as guts cardboard panel not mounted in anything - just propped up with a balsa wood rod !!
Your assessment of the dots is agreed with as far as we know so far.
Keep us posted of your experiments with the Dayton exciters.
Cheers,
Rob.
Thanks for the response, Ziggy.
I'm having fun just experimenting around right now. I need a better way of attaching these things for testing purposes, though. With tape, I get lots of buzzing at any reasonable volume.
So far, I've tried a few things (other than novelty things like picture frames, etc)
If I could get the crispness of the windows with the bass response of the heating duct, I'd be very happy, I think.
I think the power response of these things is interesting. If I sit on my couch - right next to the windows, I hear a reasonable amount of bass - same if I get very close to any of the materials. And its not overwhelmed by the high frequencies, either. But farther away, it seems that the bass dies off very quickly, while the high frequency response stays strong. I need to think about this a little bit more to come up with ideas why. These things definitely don't act like regular speakers.
I'm curious why you think that the free-floating panel is the best option.
I'm sort of fascinated with the acoustical instrument analogy. I don't know how piano soundboards are mounted, but things like guitars, violins, etc have the sounding board rigidly attached around the edge. Here are some pictures of the primary modes of oscillation on a guitar soundboard:
chladni patterns on a guitar
And, instead of stiffening the cardboard with shellac (or using a complete honeycomb structure) I'm contemplating using a set of braces on the back. Here are some pictures:
Guitar Soundboard Braces
Piano Soundboard with braces
And here's a company that makes panel speakers out of tonewood:
Opere Sonore
Looking through their pictures, it very much looks like they're using inspiration and methods from musical instrument construction.
Anyway, happy experimenting!
-Paul
I'm having fun just experimenting around right now. I need a better way of attaching these things for testing purposes, though. With tape, I get lots of buzzing at any reasonable volume.
So far, I've tried a few things (other than novelty things like picture frames, etc)
- Smallish cardboard boxes (about 1 cubic foot): decent overall sound quality, surprising amounts of bass
- Foamcore of sizes 20x30" and 40x30". These are ok, but I haven't been impressed so far. I need more experimentation, though - especially with how I set up the panel
- Corflute of 20x30". This doesn't sound much different than the foamcore, but again, I need more experimentation
- Windows: behind my couch, I've got a large window setup with 2 windows that are about 12x48" separated by a 36x48" window in the middle. The sound coming from the side windows is incredibly clear, with very crisp highs and a strong, almost headphone-like stereo image (although its more open, if that makes much sense). Its actually quite impressive! It does, however, lack in both bass and mid-bass.
- Ventilation duct: our ventilation ducts are mounted on the ceiling, but boxed in with drywall. I've had some problems hanging the transducers upside down with tape (lots of tape-buzzing and it gets loose very quickly) but the sound here is quite amazing! Not as crisp of highs as the windows, but there's definitely no lack of bass! I think the ventilation duct is acting as a sort of enclosure
If I could get the crispness of the windows with the bass response of the heating duct, I'd be very happy, I think.
I think the power response of these things is interesting. If I sit on my couch - right next to the windows, I hear a reasonable amount of bass - same if I get very close to any of the materials. And its not overwhelmed by the high frequencies, either. But farther away, it seems that the bass dies off very quickly, while the high frequency response stays strong. I need to think about this a little bit more to come up with ideas why. These things definitely don't act like regular speakers.
I'm curious why you think that the free-floating panel is the best option.
I'm sort of fascinated with the acoustical instrument analogy. I don't know how piano soundboards are mounted, but things like guitars, violins, etc have the sounding board rigidly attached around the edge. Here are some pictures of the primary modes of oscillation on a guitar soundboard:
chladni patterns on a guitar
And, instead of stiffening the cardboard with shellac (or using a complete honeycomb structure) I'm contemplating using a set of braces on the back. Here are some pictures:
Guitar Soundboard Braces
Piano Soundboard with braces
And here's a company that makes panel speakers out of tonewood:
Opere Sonore
Looking through their pictures, it very much looks like they're using inspiration and methods from musical instrument construction.
Anyway, happy experimenting!
-Paul
I did a bit more fooling around last night. I'm still not impressed with the corflute. It just doesn't have the high frequency response that the more rigid materials I've tried have. I'll be curious with any details. Perhaps you're alluding to using different sized pieces for different frequency ranges, which might make some sense. I'm kind of curious what would happen by adding some bracing onto a large panel (such as corflute) somewhat like the soundboard bracing in those links I posted.
My experimentation last night found a surprising sound quality from simply putting an exciter onto the drywall near the ceiling, but between two studs (the drywall is over brick.) Of course, the efficiency is pretty bad for a single driver and I think at least 4 would be needed to get decent SPL without compression in the drivers.
I also took out a wooden drawer from a piece of furniture that's about 16x20", placed it upside down on the carpet and put the transducer on the bottom panel of the drawer, which is 1/4" plywood I believe. So far, this might be the best sound, but again, the efficiency is poor. But it confirmed my suspicion that a wooden soundboard-like panel might be a really good option! It'd just have to be substantially thinner.
I'll be curious to hear what you're doing with the coreflute.....
-Paul
My experimentation last night found a surprising sound quality from simply putting an exciter onto the drywall near the ceiling, but between two studs (the drywall is over brick.) Of course, the efficiency is pretty bad for a single driver and I think at least 4 would be needed to get decent SPL without compression in the drivers.
I also took out a wooden drawer from a piece of furniture that's about 16x20", placed it upside down on the carpet and put the transducer on the bottom panel of the drawer, which is 1/4" plywood I believe. So far, this might be the best sound, but again, the efficiency is poor. But it confirmed my suspicion that a wooden soundboard-like panel might be a really good option! It'd just have to be substantially thinner.
I'll be curious to hear what you're doing with the coreflute.....
-Paul
O.K.....here we go.......
CORFLUTE should be renamed ''CORGARBAGE''(at least as far as panel materials go).
Yesterday I got a bit excited with a 8 inch X 6 inch piece of corflute that actually sounded better on some piano music than the cardboard. However, the larger you go, more exciters added or not, the sound deteriorates progressively. Why?....don't know.
It is not going to be used or mentioned by myself again on this thread.
FOAMCORE : DAMN IT !!!!!!!!the stuff given to me is NOT the foamcore that is suitable for panels.
There is foamcore and then there is foamcore. Here in Australia, watch out!! - because the same name applies to an artist's paper coated sheet (the stuff I have) and two other versions that are MUCH MORE RIGID.
I have a small 6 inch X 3 inch sample of the real stuff : very light and rigid with a hard eggshell like outside coating.
The sign shop that gave me this sample were not sure if it was standard foamcore or ''GATORBOARD'' (typical.....story of my life!).
Either way, the so called foamcore that I have had all this time is too soft in it's core and does not have a hard external finish.
This now opens up a new field of possibilities as proper foamcore and/or gatorboard are unlike anything I have seen or tried as yet.
I will be back at work next week and will have our contracted sign maker examine this sample and identify it for me. I will then arrange for a larger piece to be sourced for experimentation.
I still have two large articles on NXT panel materials to read which were downloaded last night. I am hoping to gain some further knowledge from this information.
As a matter to note : NOMEX is not available in Western Australia unless ordered specially in, and only in large amounts.
I can have two large panels made in Queensland with a 0.4mm fibreglass skin FOR AROUND $2,000 AUS. !!!!!!!...............pass!!!...don't think so!!........what does Nomex and fibreglass sound like?????
Also, as a matter to note : SHELLAC was successfully infused in to the corrugations of cardboard laminate. However, timing was critical as the edges tended to delaminate. The outside surfaces became ''bumpy'' - probably due to delamination beginning within the interior of the panel material.
Paul, thanks for your experimental updates. Yes, you are right about only using one exciter per panel. This is only good for background music in ceiling tiles or elevators.Hell, even two per panel ain't anywhere near enough.
I guess that a very light wooden laminate would sound great??
Problem is, where do ya get it? if ya can get it?
CORFLUTE should be renamed ''CORGARBAGE''(at least as far as panel materials go).
Yesterday I got a bit excited with a 8 inch X 6 inch piece of corflute that actually sounded better on some piano music than the cardboard. However, the larger you go, more exciters added or not, the sound deteriorates progressively. Why?....don't know.
It is not going to be used or mentioned by myself again on this thread.
FOAMCORE : DAMN IT !!!!!!!!the stuff given to me is NOT the foamcore that is suitable for panels.
There is foamcore and then there is foamcore. Here in Australia, watch out!! - because the same name applies to an artist's paper coated sheet (the stuff I have) and two other versions that are MUCH MORE RIGID.
I have a small 6 inch X 3 inch sample of the real stuff : very light and rigid with a hard eggshell like outside coating.
The sign shop that gave me this sample were not sure if it was standard foamcore or ''GATORBOARD'' (typical.....story of my life!).
Either way, the so called foamcore that I have had all this time is too soft in it's core and does not have a hard external finish.
This now opens up a new field of possibilities as proper foamcore and/or gatorboard are unlike anything I have seen or tried as yet.
I will be back at work next week and will have our contracted sign maker examine this sample and identify it for me. I will then arrange for a larger piece to be sourced for experimentation.
I still have two large articles on NXT panel materials to read which were downloaded last night. I am hoping to gain some further knowledge from this information.
As a matter to note : NOMEX is not available in Western Australia unless ordered specially in, and only in large amounts.
I can have two large panels made in Queensland with a 0.4mm fibreglass skin FOR AROUND $2,000 AUS. !!!!!!!...............pass!!!...don't think so!!........what does Nomex and fibreglass sound like?????
Also, as a matter to note : SHELLAC was successfully infused in to the corrugations of cardboard laminate. However, timing was critical as the edges tended to delaminate. The outside surfaces became ''bumpy'' - probably due to delamination beginning within the interior of the panel material.
Paul, thanks for your experimental updates. Yes, you are right about only using one exciter per panel. This is only good for background music in ceiling tiles or elevators.Hell, even two per panel ain't anywhere near enough.
I guess that a very light wooden laminate would sound great??
Problem is, where do ya get it? if ya can get it?
Ziggy said:
When it has a rigit cover it is probably rather Gatorfoam than Fome-COR (not Foamcore). Gatorfoam seems to be available in Australia:
http://www.starleaton.com.au/sds_catalogue07.pdf
Tried the GATORFOAM with my experimental piezo driver taped on to the back of the sample. Amazing difference in output level and high frequency performance compared to everything else tried so far (by far).
GATORFOAM is actually a ''wood'' fiber, resin impregnated coating sandwiched between polystyrene board which will interest Paul in his recent experiments with wood as panels with his exciters.
It is also known for it's hardness of the surfaces (the first thing you notice including lightness) , high rigidity and resistance to warping and delaminating. When dropped from a small height on to a table top, it has a distinctive hard ''plink'' sound so a large piece should resonate nicely without being over damped.
Hope that this will end the search for a suitable and readily available material (if I can get it in small quantities).It is more expensive than your regular foam-cor which can be expected.
GATORFOAM is actually a ''wood'' fiber, resin impregnated coating sandwiched between polystyrene board which will interest Paul in his recent experiments with wood as panels with his exciters.
It is also known for it's hardness of the surfaces (the first thing you notice including lightness) , high rigidity and resistance to warping and delaminating. When dropped from a small height on to a table top, it has a distinctive hard ''plink'' sound so a large piece should resonate nicely without being over damped.
Hope that this will end the search for a suitable and readily available material (if I can get it in small quantities).It is more expensive than your regular foam-cor which can be expected.
How's this for service????.........I have two 78inch X 28inch X 1/4 inch(actually 5mm) black panels of Gator-foam arriving tomorrow My choice for this size, especially the height, is that there will be a further possibility of adding two more exciters per panel making it 8 per side. Plus I have stuck to the ratio that is used by the Podium Speakers, only going larger.Have researched some interesting and very useful information on how to mount the raw exciters(without the crappy plastic arms and cardboard disk) to the panels and how the panels can be secured to frames and suspensions.
This is getting EXCITING !! (pun intended
).Thanks 8cube ......you're welcome.
The GATORFOAM has arrived !.....weird stuff, light, rigid and very hard faces.
Once again I stuck on my small experimental piezo cone on to a 4 foot X 1.2 foot (approx. ) offcut of Gatorfoam.
Yes,.......this is what works the best, no doubt about it.
A small piezo(besides sounding like a 2 inch moving coil speaker!) actually induces small vibrations that you can feel by lightly touching the panel edges! A wrap on the panel with my knuckles produces a resounding loud knock which is good news.
Next stage is to test a very strong clear double sided tape used to stick down carpets and vinyl floors. This will be used to mount the exciter foot to the panels.
I have already found something suitable in a rubber goods supply store and will buy a roll soon.
Then the lenghty process of removing the rest of the exciters from the Soundpads will follow. I have been informed that I only need one 1.6 amp PTC resistor for the 6 exciters at the input terminals which is good news.
Will post some photos of the work in progress when I get a chance.
The GATORFOAM has arrived !.....weird stuff, light, rigid and very hard faces.
Once again I stuck on my small experimental piezo cone on to a 4 foot X 1.2 foot (approx. ) offcut of Gatorfoam.
Yes,.......this is what works the best, no doubt about it.
A small piezo(besides sounding like a 2 inch moving coil speaker!) actually induces small vibrations that you can feel by lightly touching the panel edges! A wrap on the panel with my knuckles produces a resounding loud knock which is good news.
Next stage is to test a very strong clear double sided tape used to stick down carpets and vinyl floors. This will be used to mount the exciter foot to the panels.
I have already found something suitable in a rubber goods supply store and will buy a roll soon.
Then the lenghty process of removing the rest of the exciters from the Soundpads will follow. I have been informed that I only need one 1.6 amp PTC resistor for the 6 exciters at the input terminals which is good news.
Will post some photos of the work in progress when I get a chance.
Over the weekend I mounted a raw exciter (removed from the soundpad casing)with a clear double sided tape on to the Gatorfoam. This tape is used to hold down carpet and vinyl floors and it's very strong.
Wow !!.......I am very impressed with the sound. It is noticeably louder, crisper and dynamic when compared to all other prototype materials. The sound now falls in to the realms of serious performance capabilities. This is FAR from ''mid-fi''in my opinion.
I think I have finally cracked the affordable panel material problem!.....its not the best, the most rigid or the lightest, but hey, it works VERY nicely!........far better than expected.
Also got an email response from NXT (finally!) regarding panel materials. Recommendation basically boiled down to numerous already tried materials and the reason and need for light and rigid materials and the problems related to not sticking to these requirements.
Of special interest was a comment that the SOUNDPADS ''casing '' is detrimental to the sound. Something that has been under suspision all the way along.
?? I have also asked NXT for any further advice on the project where or if applicable.
It's ''full steam ahead '' from here
Wow !!.......I am very impressed with the sound. It is noticeably louder, crisper and dynamic when compared to all other prototype materials. The sound now falls in to the realms of serious performance capabilities. This is FAR from ''mid-fi''in my opinion.
I think I have finally cracked the affordable panel material problem!.....its not the best, the most rigid or the lightest, but hey, it works VERY nicely!........far better than expected.
Also got an email response from NXT (finally!) regarding panel materials. Recommendation basically boiled down to numerous already tried materials and the reason and need for light and rigid materials and the problems related to not sticking to these requirements.
Of special interest was a comment that the SOUNDPADS ''casing '' is detrimental to the sound. Something that has been under suspision all the way along.
?? I have also asked NXT for any further advice on the project where or if applicable.It's ''full steam ahead '' from here
Ziggy,
what i your impression about distortion? I once played with a ceiling speaker with flat diaphragm of expansed polystyrene, damn fast but far from neutral.
The Nomex honeycomb paper of the Podium Sound is very uncolored to my ears, but the highs are not as I would like them to be.
I wonder why there haven´t been any efforts of developing suitable compound materials by NXT themselves. By saving the fees for a few hundred doubtful patents this would have been possible, I guess.
what i your impression about distortion? I once played with a ceiling speaker with flat diaphragm of expansed polystyrene, damn fast but far from neutral.
The Nomex honeycomb paper of the Podium Sound is very uncolored to my ears, but the highs are not as I would like them to be.
I wonder why there haven´t been any efforts of developing suitable compound materials by NXT themselves. By saving the fees for a few hundred doubtful patents this would have been possible, I guess.
el'OL, GATORFOAM does not look like, feel like or sound like your average ''polystyrene foam''.
Remember that Gatorfoam is the ''durable version'' of extruded polystyrene and is not your regular cheap, common surfboard type material.
I have owned and used the BERTAGNI style foam panel/moving coil speakers and their sound was not acceptable in my books - the mids were awful and the highs were very rolled off, allmost not even there. Their sound was TOTALLY DIFFERENT to what I am hearing with the Gatorfoam and so it should be, besides operating on a totally diffrent driver principle, it's a different type of foam and is laminated with a very tough, hard, wood fiber resin compound - that is the key to good sound properties - rigid yet light.
The main difference between all the other materials I tried is the high frequencies - the most important part. Gatorfoam lets them through significantly better. But, it's not a direct firing dome tweeter and never will be. To me it's a much more natural sound that's more like listening to real instruments but that's just my opinion.
I have not noticed any distortion as such. I presume you mean the ''polystyrene sound'' ?Well, it's not there at all.
Received a follow up email from NXT yesterday and they are familiar with the use of Gatorfoam and have had speakers built by various companies using Gatorfoam. They mentioned that it is a good cheap alternative to Nomex but also said that the honeycomb stuff sounds better although it is much more expensive and made in China!!
(What???)
NXT also asked if I was interested in different higher powered drivers amongst the'' hundreds of different types'' available (just goes to show that the technology is advancing while most of us ''Audiophiles'' are ignoring it or diregarding it as useless for high end use) and that they could sell to me direct without the need for licensing which is pre-paid for small businesses and Universities etc.
I have asked for a brochure/product list and prices.
I hope to have the two panels with the raw exciters mounted and wired up this week.
They won't yet be mounted in frames, but I'll know the results soon enough. If they sound great that will be nice, if they don't, there will be room for experimentation.
Remember that Gatorfoam is the ''durable version'' of extruded polystyrene and is not your regular cheap, common surfboard type material.
I have owned and used the BERTAGNI style foam panel/moving coil speakers and their sound was not acceptable in my books - the mids were awful and the highs were very rolled off, allmost not even there. Their sound was TOTALLY DIFFERENT to what I am hearing with the Gatorfoam and so it should be, besides operating on a totally diffrent driver principle, it's a different type of foam and is laminated with a very tough, hard, wood fiber resin compound - that is the key to good sound properties - rigid yet light.
The main difference between all the other materials I tried is the high frequencies - the most important part. Gatorfoam lets them through significantly better. But, it's not a direct firing dome tweeter and never will be. To me it's a much more natural sound that's more like listening to real instruments but that's just my opinion.
I have not noticed any distortion as such. I presume you mean the ''polystyrene sound'' ?Well, it's not there at all.
Received a follow up email from NXT yesterday and they are familiar with the use of Gatorfoam and have had speakers built by various companies using Gatorfoam. They mentioned that it is a good cheap alternative to Nomex but also said that the honeycomb stuff sounds better although it is much more expensive and made in China!!
(What???)NXT also asked if I was interested in different higher powered drivers amongst the'' hundreds of different types'' available (just goes to show that the technology is advancing while most of us ''Audiophiles'' are ignoring it or diregarding it as useless for high end use) and that they could sell to me direct without the need for licensing which is pre-paid for small businesses and Universities etc.
I have asked for a brochure/product list and prices.
I hope to have the two panels with the raw exciters mounted and wired up this week.
They won't yet be mounted in frames, but I'll know the results soon enough. If they sound great that will be nice, if they don't, there will be room for experimentation.
UPDATE :
Further emails back and forth from NXT have proved to be very useful.
Received some specifications and links to the Chinese supplier of exciters of various types. Of special interest was the largest and most powerful in the range : a 4 ohm unit (also a 25mm voice coil and identical spider and foot to the one's I have)that looks like the type used in high power ceiling panels and the Podium Loudspeakers.
Some questions were put forward to NXT on whether the Chinese honeycomb panels would be significantly superior to Gatorfoam as well as the possible benefits of using the more expensive and higher powered exciters instead of the standard ones I am using from the Soundpads.
Boiling all this down and by looking at the electrical/mechanical parameters, the use of a different exciter will provide only a minimal improvement in overall sound quality plus a 2.7 db increase in sensitivity per exciter and of course greater power handling(but still only 79db and 20 watts MAX per exciter).
It seems apparent that the Gatorfoam is more than adequate as a good performing panel material and there is no real justification to go down the honeycomb(Nomex equivalent) pathway without considerable expense and trouble. Especially as the panels are supplied uncut and cost a fortune to ship over from China.
So, at this point in time,and after nearly 8 months of research on my part, and the recent conversation with NXT themselves, I think that as a D.I.Y. large NXT type panel loudspeaker, I have covered all bases and have not overlooked any cheaper or significantly better performing products/parts.
As mentioned, the exciters are currently being removed from their housings(what a crappy and delicate job!) and will be mounted on the intended panel surfaces and ready by the weekend for a trial run.
Wish me luck !!!
Further emails back and forth from NXT have proved to be very useful.
Received some specifications and links to the Chinese supplier of exciters of various types. Of special interest was the largest and most powerful in the range : a 4 ohm unit (also a 25mm voice coil and identical spider and foot to the one's I have)that looks like the type used in high power ceiling panels and the Podium Loudspeakers.
Some questions were put forward to NXT on whether the Chinese honeycomb panels would be significantly superior to Gatorfoam as well as the possible benefits of using the more expensive and higher powered exciters instead of the standard ones I am using from the Soundpads.
Boiling all this down and by looking at the electrical/mechanical parameters, the use of a different exciter will provide only a minimal improvement in overall sound quality plus a 2.7 db increase in sensitivity per exciter and of course greater power handling(but still only 79db and 20 watts MAX per exciter).
It seems apparent that the Gatorfoam is more than adequate as a good performing panel material and there is no real justification to go down the honeycomb(Nomex equivalent) pathway without considerable expense and trouble. Especially as the panels are supplied uncut and cost a fortune to ship over from China.
So, at this point in time,and after nearly 8 months of research on my part, and the recent conversation with NXT themselves, I think that as a D.I.Y. large NXT type panel loudspeaker, I have covered all bases and have not overlooked any cheaper or significantly better performing products/parts.
As mentioned, the exciters are currently being removed from their housings(what a crappy and delicate job!) and will be mounted on the intended panel surfaces and ready by the weekend for a trial run.
Wish me luck
!!!O.K, ........COULDN'T HELP MYSELF!..........last night I mounted one (yes, ONE ONLY!!) exciter on each of the giant GATORFOAM boards that I had cut to size.
I placed the raw exciter around the middle of each panel, but off to the side slightly.
Results?................
That's ONE driver only folks.....remember that!...........and that is why the Gatorfoam is that good The HIGHS are GREAT!
I placed the raw exciter around the middle of each panel, but off to the side slightly.
Results?................
That's ONE driver only folks.....remember that!...........and that is why the Gatorfoam is that good
The HIGHS are GREAT!
Thanks for all the updates, Ziggy. Nice horns! Also - did you get black gatorfoam, or did you paint them black? Those are pretty massive panels!
I personally haven't had much time for experimentation the past week or so. A couple of weeks ago, I did buy some wood panels and boards to try out. Here's the quick summary:
24x48x3/16" plywood panel: again, crisp highs and surprising bass extension, but very poor sensitivity
I personally haven't had much time for experimentation the past week or so. A couple of weeks ago, I did buy some wood panels and boards to try out. Here's the quick summary:
24x48x3/16" plywood panel: again, crisp highs and surprising bass extension, but very poor sensitivity
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