[zygadr]

I tried to get some sound out of a square tube of carbon fiber once. The sound was very bright and harsh and would ''ring'' with a steely screech that was very unpleasant to the ears.
I would guess that the C.F. would need much experimentation in to dampening the resonances as does any hard surface material. Aluminum reacts in the same way.

This is why the use of paper(C.C) or EPS  has yielded the best results for most of us so far. They both produce good sound and are ''self dampening ''to some extent which makes them useable straight away and are open to further dampening with experimentation should you feel the need for it.

I will soon try two cross layered and laminated sheets of balsa wood (home made balsa plywood) to see if the sound is acceptable. It is easy and not too costly to try so I am hoping that some of that ''magic'' plywood sound can be obtained with good output as well..........we shall see

[b2m]

Hey Zyg,

interesting. a carbon squre tube sound extremely stiff. The biggest readily available size is 1100*700mm which should be about right. Thickness is my concern, I can get them in 0.2, 0.5, 0.8 and 1mm (or more). Any thoughts or adivce? My guess is that 1mm my even be too stiff. I have to order them as there is no dealer in town who stocks it.
I know it's hard to do guesswork on this, but if you have any idea which thickness may be the best, I'd be delighted.

I think I will build a CC in parallel to find out what sound better.

[zygadr]

Hi b2m.
The stuff I had was around 1mm or so if I recall correctly. Have no idea how the different thicknesses will affect sound/ringing/dampening. You will have to experiment with C.F. as this is an unknown material here for most of us.
Remember that natural sound is all derived from wood and paper (Mother of Tone). .............however, ''Carbon''should fall in to this category also you would think?

[bobloblob]

Carbon fiber is usually used in sheets, and is essentially a cloth.  If you are using a carbon fiber panel, then that is the carbon fiber cloth in a matrix of something like polyester, epoxy, or phenolic resin.  In this way it has similar properties to the fiberglass/polyester resin in boat hulls, surfboards, and car bodies.  You could vary the properties by varying the substance in which it is embedded.  I wouldn't blame the carbon fiber itself for whatever sound characteristics you are hearing.  Laying the carbon fiber cloth over something like a thin sheet of balsa and pouring another substance over it - polyester, epoxy, varnish, shellac, lacquer - may give some interesting results - who knows?

[zygadr]

Carbon fiber is usually used in sheets, and is essentially a cloth.  If you are using a carbon fiber panel, then that is the carbon fiber cloth in a matrix of something like polyester, epoxy, or phenolic resin.  In this way it has similar properties to the fiberglass/polyester resin in boat hulls, surfboards, and car bodies.  You could vary the properties by varying the substance in which it is embedded.  I wouldn't blame the carbon fiber itself for whatever sound characteristics you are hearing.  Laying the carbon fiber cloth over something like a thin sheet of balsa and pouring another substance over it - polyester, epoxy, varnish, shellac, lacquer - may give some interesting results - who knows?

Yes, I believe there is a loudspeaker hybrid using NXT and C.F./Balsa wood technology. Just can't remember the brand?
The link may have been posted on this thread not so long ago???

[Nickolay V]

Very important event with NXT and BMR technologys  owner:
http://www.electronics-eetimes.com/en/nxt-assets-sold-to-us-audio-firm.html?cmp_id=7&news_id=222917873#
And  extremely  significant NXT  product of  last ten years :
http://www.tectonicaudiolabs.com/products/panels/
http://www.tectonicaudiolabs.com/about/demo-chronicles/production-plates-debut/

Very interesting what kind diaphragm and exciters  in this panels used  ?

[Nickolay V]

Info from Tectonicaudiolabs  letter  answer to my request:

We have recently finished our new design and are now manufacturing panels for sale (some pictures of the new panels are attached).  The first panels are being sold in the USA, and then beginning Q2-2014 we expect to be selling internationally.

The USA pricing is $14,000 USD retail price for each panel.  There will also be an amplifier/controller which operates two (2) panels, which will be $6,000 USD retail price.  This means that one pair (left/right) of Tectonic Plates + Amp/Controller is $34,000 USD retail price; this system can easily cover 300 to 1,000 seats, depending on the shape of the venue.  For example, a 5x5 panel system easily covered a 5,400 seat venue.

We have demonstrated the system in several multiuse theaters in the US.  One of our first installations will be in the Empress Theatre in Vallejo CA USA.  We also conducted a demonstration in the  Fox Theater in Salinas CA USA.  Additionally, we have provided the sound system for a concert called “Elvis Lives” in the Paramount Theatre in Seattle WA USA.

The panels provided clear and intelligible sound, especially with vocals even during complex passages, while in these difficult venues (many sound reflections).  Another other very strong feature is the lack of microphone feedback, which you can see on our website  here and in a video of experts speaking about the system  here.  The system also has nearly zero 3rd order harmonic distortion (which is a key reason why the human voice is so clear).

The system is truly an audiophile grade system.  We have auditioned the system with some of the finest electronics and source materials available, and the results are wonderful; sounding like a giant audiophile sound system.

[zygadr]

Hi Nikolay, unfortunately my computer's virus protection will not allow me to view the links.

These products are EXTREMELY expensive!...............we can achieve the same result (maybe?) for next to nothing in D.I.Y.

[Nickolay V]

Hi Zyggy !  Quite the contrary. In DIY we are able to make IDENTICAL PANELS much cheaper and  even much perfect. We must try !!!
Tectonic panel size 60"x20"x3", and it work from 80Hz
( By my calculation, summary panel diaphragm  surface area is about 0,55-0,6m2 )

And now we are experimenting  with Rohacell 31 + Carbon Veil  laminating

[emailtooaj]

Very interesting post Nickolay!

I had visited the links and I'm impressed what they have accomplished.
I think what I find even more validating is their selected panel size that you had posted (60x20x3).
Not in terms of surface area size, but the width and length ratio's. Their panel width is 33% of the chosen length.
For the panels I've been using, I've calculated them (if I remember correctly) based on the "golden ratio".
My panel size is 48"x16". And guess what ratio that equates to be?.... 33%

Not trying to toot my horn  but just reiterates what has been going on in this forum, how correct we have been (as a whole) with certain parameters of this technology, and building them our own ways to satisfy/challenge our individual imaginations.

Question is, how much further can we take it to be more effective and efficient with out breaking the bank!

Peace!

[zygadr]

Very interesting post Nickolay!

I had visited the links and I'm impressed what they have accomplished.
I think what I find even more validating is their selected panel size that you had posted (60x20x3).
Not in terms of surface area size, but the width and length ratio's. Their panel width is 33% of the chosen length.
For the panels I've been using, I've calculated them (if I remember correctly) based on the "golden ratio".
My panel size is 48"x16". And guess what ratio that equates to be?.... 33%

Not trying to toot my horn  but just reiterates what has been going on in this forum, how correct we have been (as a whole) with certain parameters of this technology, and building them our own ways to satisfy/challenge our individual imaginations.

Question is, how much further can we take it to be more effective and efficient with out breaking the bank!

Peace!

Hi Zyggy !  Quite the contrary. In DIY we are able to make IDENTICAL PANELS much cheaper and  even much perfect. We must try !!!
Tectonic panel size 60"x20"x3", and it work from 80Hz
( By my calculation, summary panel diaphragm  surface area is about 0,55-0,6m2 )

And now we are experimenting  with Rohacell 31 + Carbon Veil  laminating

Yes!...................just look how long this thread is and how many views it has!
I too wonder what the future holds with our panels. All that I know is that magnetic planar and electrostatic speakers have now some serious competition at a fraction of their build price, and a lot less work in making them!

For quite some time now, I have completely forgotten about the sound of my audio system and it's components...............I JUST LISTEN TO MUSIC..................isn't THAT WHAT IT'S ALL ABOUT?????

[bobloblob]

Haven't seen any posts by POL on this thread recently.  I liked the idea of the large single cc panel he made, the one with the exciters mounted in left, center, and right groupings.  The last post of his that I remember he had to travel somewhere for work and built a two-panel system using plywood, IIRC.  This thread has narrowed down to a two-panel system using cc, which may be the way I go when I get the chance (still wrapped up in personal/financial issues getting in the way of really important stuff like stereo/hifi and MUSIC!).  However, I like it when some lateral thinking like POL'S comes in occasionally, as Zygadr's did when he began building his exciter systems early on, then started this thread.

So, POL. if you are still around, what is the present status of your system?  Have you gone back to a single panel cc yet, or have you given that up?

[emailtooaj]

Well, here are the new Voice Coil bobbin/former/foot for the experimental exciters 
Something so damn simple but yet so complicated   



On with the next phase!!

Peace!

[zygadr]

Looking good emailtooaj!!!!!! ...........tell us a bit more on how you made them and why they are taller than usual?
What are you going to use for your magnet system?
Now........................what's next???????

[emailtooaj]

Hey Zygadr,
Thank you for the thumbs up 
Well... in a nut shell... I had to make my own VC using various parts and then make a silicone mold of it. After getting the mold finished I can now make a one piece VC unit by using a poured, fast curing/setting plastic. Dascar plastic's has a brilliant formula called RP-40. It sets in 2 minutes, can be de-molded in 15mins. and is highly accurate in reproduction! The other great aspect of this RP-40 is it has a temp rating of 350*F, is very light weight (2 grams for whole VC bobbin) and has a nice crisp ring/sound to it when you scrap the bottom of the former after it cures. So it shouldn't dampen any voice coil energy and transfer it to the panel efficiently.

.......tell us a bit more on how you made them and why they are taller than usual?

The VC bobbin in the photos are 1.25" tall, from the Foot to the bottom of the bobbin. This will actually be to tall! I'll need to shred off about a .25" from the bottom.

What are you going to use for your magnet system?

I will use a Neo magnet for the magnet system. With what I have in mind, each exciter should only require one magnet. I've been considering a .625" Dia. by .25" thick neo magnet, but I'll have to confirm that down the road.

Now........................what's next???????

Next is designing the housing unit and making a mold for that also. This has been the most challenging for me to finalize!! I'm so back and forth on what to do
I'm considering a way to be able to adjust the magnet, so I can "fine tune" the coil/magnet field interaction.
One reason being is to get the max VC interaction while keeping the electrical stuff in line, like voltage/resistance swings.
Reason #2, after fiddling with my prototype, while I was moving the magnet in/out of the coil gap, I noticed it might be possible to create a passive x-over just by changing the distance of the magnet to the coil?!!!
I can't prove this at the moment, but I was encouraged with what I heard while messing around.

If anyone out there would like to donate a desk top metal lathe to me  I could create these parts much quicker 
If I had $600 to drop, I would just get one from Harbor Freight and be done with it 
All the machine shop's in my area want to charge some stupid high fee's for what little work is actually needed for these parts. So I've had to resort to other means and get this done.

Like we had talked in the past Zy, I've been trying to find ways to eliminate any possible distortion/failure points and by going with this "one piece" VC bobbin, will be a path in the right direction.
I'm also considering a double spider setup to help with any VC drop, which I've found is another source of distortion with these "El-Cheapo" exciters.
The weight of the panels and gravity are not friends to a single spider design IMO. Even if you have some type of panel support.

But overall, I'm planning to have the final exciter no more than 1.75" deep, from exciter foot to the back of the housing. Still trying to keep it "low profile" as much as possible.

Peace!

[zygadr]

Well,..............I take my hat off to you emailtooaj!
It seems that you have put in a lot of work in to this exciter design and I really hope it comes off well for you( and all of us..... hint.....hint.... ). No doubt, if it turns out to be a superior exciter, we will be entering a new stage of development and experimentation to what is already a GIGANTIC thread!

Just a suggestion, ...................it would be awesome if we only end up needing ONE exciter instead of multiple units. I know that this would mean that the new motor would need to be very high powered and efficient, but it would certainly be ground breaking to say the least!

[emailtooaj]

Just a suggestion, ...................it would be awesome if we only end up needing ONE exciter instead of multiple units. I know that this would mean that the new motor would need to be very high powered and efficient, but it would certainly be ground breaking to say the least!

Well...needing only one exciter would be ideal 
Since you brought up the subject...and I welcome all input from other members also... What would be the suggested Ohm rating? If the goal is to use one exciter then I would guesstimate that most people would prefer an 8ohm load?
If using a 2 exciter design in series, would get you a 4ohm load (I've used 2 in series before and the sound is better than parallel IMO).
Of course I could wind them in 16ohm each to run in parallel to get the 8ohm load....
I could go all day long with different configurations 

What is everyone's ideal set up??? Suggestion/Input welcomed!!!

Peace!

[zygadr]

I think a single 8 ohm unit would be the best choice as most sytems are standard at that impedance.
Thing is, can you make an efficient/high powered single unit that will do the job? 

[duquette5]

Ok I finally took four of the nxt's (I bought 10) from parts express and wired them in series and hot melt glued them to a piece of 5mm Birch plywood. It's a 24"x21" panel and I placed the 4 based on calculations from Monacor's patent filing (Thanks for posting that Wires!). I cheaped out and wired them to a single rca jack to test with. Plugged in my iPod and was surprised by the sound quality. Bass is not it's strong point, however the rest of the sound was pretty filling. It seems that Wires and I have the same or a similar goal in mind. I'd like to create a "hidden" surround sound system using these.

The plan:
5.1 surround based on the NXT exciters.
Each panel will be mounted (shellaced (SP?)) to a sheet of either silk or thin canvas with artwork on it then stretch mounted to a wooden frame and back braced.
Most important: Keep the wife happy...

The gaps:
How to drive it
hidden subwoofer solution
# of exciters per panel keeping them around the 24x21 size.

Input always appreciated!

>M<

[mightym]

Wow, I unsubscribed from this thread quite a while ago, I see that much has changed since.

I've been re-reading and catching up for the past few days and have a couple of questions, and possible a suggestion.

Jim Gale: When you treat the CC with shellac, if I understand correctly you just dribble the shellac down the flutes until it runs out the bottom?  Then re-treat and put a couple of coats on the outside of the CC?.....

Wires:  Thanks for posting that Monacor info, could you provide a link to the source of the size ratio's you posted?  I'm trying to decide on the ultimate size, possibly how small can I go without loosing too much.  I've always planned to cross to a sub....

I've seen several posts that alluded to not blocking the edges of the panel, that it restricted overall sound output.  I've been thinking about a completely different mounting/suspension arrangement that employs the areas shown on the screen shot Wires posted.  My idea is to apply a short bit of dowel to the areas that are along the centerline shown in the darkest blue, and suspend that to another bit of dowel with a smaller diameter on the spline with a bit of elastic.  this would allow the panel to move forward and backward as needed, but also support the vertical weight of the panel.....

I'm going to try and do a Sketchup of my concept and post for comments in a few days.

Glad that progress is being made....

John