[CLS]

But rigidity is a relative term. Nothing is absolutely rigid.

The speed of sound wave propagating along the surface of certain type of material is constant. So, when the frequency goes up, the wave length goes shorter. Up beyond a certain point, inevitably, there'd be several bumps and dips on the panel.

How many bumps and dips is optimal for 'distributed' mode? While this is varied with frequency range and type/size of panle....

[zygadr]

But rigidity is a relative term. Nothing is absolutely rigid.

The speed of sound wave propagating along the surface of certain type of material is constant. So, when the frequency goes up, the wave length goes shorter. Up beyond a certain point, inevitably, there'd be several bumps and dips on the panel.

How many bumps and dips is optimal for 'distributed' mode? While this is varied with frequency range and type/size of panle....

CLS, I'll be the first to admit that I don't have the answers for you. Read NXT's white papers or ring them......if you're game!

You would be better off asking these questions on the DIY AUDIO forum where you also belong to and post on this technology.............that's where all the ''experts'' are.............AND..... the individuals who lurk there and occasionally post that these panels are ''complete garbage''.

I started that thread over there a long time ago with only the best intentions.
My reward for my efforts was regular, ugly and personal attack(sometimes in the form of P.M.'s) from certain individuals until I eventually ''cracked'', removed all my posts and responded inappropriately in my defense against one idiot who made a suggestion to me openly on the forum that was sexually offensive!!!
That was deemed to be o.k by the moderator, but MY response was not and I was thrown off the forum permanently. Thank you DIYAUDIO.

I began a new thread here and am happy to say that the beahviour towards me has been more favourable - mostly.

I know this much: I took a toy that cost very little, experimented over hundreds of hours with many exciter configurations, panel materials, coatings, mounting methods and eventually came up with an effective, great sounding panel speaker that can rock with the best out there.

As I get older and life gets shorter, no one can take this success story away from me............NO ONE...........I did it..............for the record........ for ever.

[CLS]

Sorry to hear that story.

I've been posting there, yes, on varioius topics. I'm also getting tired of all those hair splitting debates and "political correctness" about all those "scientific proofs" of things (a.k.a. 'measurements'.... ). It's not that these rational things themselves are bad, it's about the mindset/attitude in both communication and thinking.

I also posted my panels in diyaudio, too. I got largely ignored, only very few responses. (some very good ones from a kind member, LineArray, though). I guess I got no more motivation to try over there anymore. There've been several cases that I was attracted by some very interesting ideas that only a handful of people were really involved. And then the small group would be treated like an odd ball party. LOL

Oh yes, revelations are not for everyone.

......

Back to the topic, white paper? Sorry I must have missed it. I browsed through this whole thread several times, and read all links as far as I can. I don't remember and haven't found a white paper. And also got nothing from google. Would you please point me a link?  Thanks a lot




 

[CLS]

BTW, here's another trial.

I started playing with the little excitors in the office I work. There's a large piece of glass beside my desk, about 1.2m height by 5m wide in totall, installed on a (wooden) dry wall as a partition. The office area is about 8m by 10m. The other side of this dry wall is a larger lab area of 12~14m square or so.
 
By double side adhesive tape, 2 excitors were stuck on the glass. Driven by a tiny chip amp and web radio on my PC as source, they sang. Unexpectedly, without EQ it's the same thin sounded character as my previous trial panels. Only 1 excitor per channel, so no load distribution trick can be applied for bass augmentation, I use EQ in PC. It needs about 15dB shelfing filter (boosting LF/ attenuating HF) to make it reasonbly flat.
 
The major difference is this glass/wood wall is much much more rigid and heavy than my foam boards. There's a very pronounced LF resonant peak, I guess it's somewhere between high 30's to low 40's, at which point the whole wall is rattling, if playing loud enough (and that's NOT loud at all). The EQ function in media player (foobar 2000) is very limited, down to 55Hz only! So that resonance can't be suppressed.
 
OTOH the midrange and HF is very detailed and extended. Very crisp sound.
 
The poor little chip amp is seeing the earphone output of my laptop PC which is much lower voltage than standard line level. So the total avaible gain and volume is very limited. Nevertheless, for quiet background music in office, it's enough. No need for high SPL, and that LF peak must be avoided anyway. Its large radiation surface makes the sound very effortless and also clear under low SPL.
 
My colleagues were curious about the excitors at first and then quite happly with the sound. They know nothing about audio and music, but still happy, oh well...

So, it's a fun trial and also a very practical system to please people. Once the obsession of pursuing "the best" is put down, there'll be a whole lot of possibilities. 

Have fun.

[zygadr]

CLS, I'll try to find that link for the white paper, but be warned.............it's a killer!!!

Glad to see you're trying various surfaces.............it's fun, and educational at least.

Tell me, ...................on ''THAT OTHER'' forum, someone has made some panels with Sitka Spruce and the CLARK SYSNTHESIS tactile transducers from Parts Express.
This is very interesting as I've allways disregarded those tactile transducers as ''bass only'' applications?
It seems that they can do full range at very high shove power and power input...............much more than what these tiny exciters can handle.

What do you think?..................this is worth investigating I think

[CLS]

The guy who built piano sound board has disappeared for about 2 weeks. I never saw a picture. What a pity. I guess it'd be very good. (by the experience of glass/dry wall  ... )

I have two Dayton's bass shakers, smaller ones. (but still much larger than the cheapo tiny excitor). I've been thinking of using them on separate panels for bass, but not done anything to them yet. I will, just don't know when.... 

[pol_bct]

> Clark Synthesis TST209 Tactile Transducer

those are on my list of next things to try

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-861

and yes ! some wood panels sound great

POL

[sedge]

NXT is now called HIWAVE!!........ Whoopee!
Their site is not very informative.

Cls
Checked out that exciter at PX and it is expensive.
So will not be smashing up my wife’s piano.
Recommended minimum 150 watt amp to drive it!


NXT failed to make a panel that actually sounds good in hifi terms
the white paper although interesting is just to put their stamp on their patent ,so that they can make lots of money on the toys they sell .
  sedge
 

[zygadr]

Sedge, learn how to spell my forum signature first before I take you seriously

I don't know what you were trying to prove in your last post except that maybe you should stay in ''THAT FORUM''.

If you are trying to get me angry by taking the piss, then keep trying.............it won't work.
I have come in to contact with so many stupid posts and people like you that it makes no difference to me...........none at all.

I had respect for you in the past, but after that nonsense you posted, you will only be laughed at by all from now on.
That will be your ''lump of shit'' hitting the fan.

CLS is not to be targeted by you or anyone as he has the guts to try new things and I commend him for that.

POL, yes, I'm looking at this very closely and it too may be my next purchase...........especially with the drop in price : $69 US is not that much to pay for a trial on various woods.

[sedge]

Yes zygadr , it is a stupid post .
But in it I was giving support to you ,not knocking you.
The point I was making (obviously not in a very funny way)was that you had succeeded where they had failed  and that was why you got so much flack.
Hence every time you succeeded you got another lump of shit hurled your way.

As for targeting CLS .
If you could point out what I have said to target cls it would be very helpful as I am unaware of doing so,but if I have unwittingly done so I will apologize unreservedly.

I hope this clears up this misunderstanding.
I will leave the post for you to read again ,then I will delete it.
sedge
 

[trucker]

These pictures show my panels: I thought you might find it interesting. The eps panel is 120 cm x 60 cm- I couldn't get it any larger here in denmark. I'm using two exciters per panel, mounted 1/3 and 2/3 along a vertical centerspine, using dobbelsided tape. Additionally, the panels are supported by a small screw in each corner of the frame that "bite" into a small wooden slab glued onto each corner of the panel. See for yourselves:














I too work as a teacher, and have been building panels in my class. Most of the kids thought it very cool and exciting.

I'll be getting some patek se amps soon to try out and a new DAC too.  I'll report back if it makes a difference or not. I expect so, as I'm using somer very old low-fi electronics.

Almost forgot.. They play very nice 

[zygadr]

OOPS!

My sincere apologies sedge!

I must have been half asleep when I read your post as it didn't click at the time that you were on my side................also, you have not targeted CLS.......I was only protecting him from the possibility that he may be next

I can say that if it wasn't for the the famous ''sedge SCRATCH TEST'', the discovery of VH EPS would not have been made .............so thanks for that!!

trucker...........very nice work pal..................simple and effective............congrats! 
Can you tell us some more?..........................I see you have the exciters mounted on a spine.
Has this method worked for you?

[CLS]

Hi zygadr,

No problem, and thanks a lot. 


Hi Trucker,

Well done indeed! Congratulations

Several questions:

* Is your panel supported by the screws or those small wood slabs? (pin poinst vs small contact patches)

* How is the support system withstand high SPL (excursion)? Would there be any audible frictions/squeaks/scratches? I suppose that is a 'hard' securing mean.

* What (where) is that slab in the 3rd pic? What's the purpose?

 

[jackman]

Hey guys, I bought some of these and would like to begin experimenting with differnt surfaces.  How do you get them to stick?  What kind of glue do you use or can you use double sided tape?  Thanks!

J

[pol_bct]

Hi
after struggling with double side tape, who does not stay very long in place
I am now using neoprene "colle rapide" SILEA, It needs a long night of rest before
turning the amplifier on, but it sticks very strong transducer and panel together.

POL

[jackman]

Hi
after struggling with double side tape, who does not stay very long in place
I am now using neoprene "colle rapide" SILEA, It needs a long night of rest before
turning the amplifier on, but it sticks very strong transducer and panel together.

POL

Thanks!  I will try it out. 

[CLS]

When I experimented with CC, I applied a layer of thin transparent tape (usually for carton) on the paper suface, then the double side adhesive tape and excitor. It stayed for one night in the first trial. In the second trial, it stayed longer.

And the for the later foam panel, I used 3M tape. I don't know its model (not VHB), just from ordinary bookstore. The package says "twice as sticky... " sort of thing. It stayed for several weeks now. Or maybe the 'anti-gravity' support system help a lot, too Nevertheless, it's really sticky. There was once I had to pull it off for adjusting the alignment, dxxn it's really sticky! I was worrying the excitors would be damaged. They were not, while the panel was.

[sedge]

My wife popped out for a short while, so I decided to try and get some measurements of the 2x4 panel with 2 exciter hanging off the back.
I had to set everything up  in the front room as fast as possible.
It was very rushed but I hope it gives an idea of what is going on ,on the panel .
The mic cable only stretches three or so Ft into the room so I had to move the panel  towards the door in the corner of the room,not the best place , but I think it gives a good idea of on axis and off axis response.
The panel was 130cms from the mic  and when turned sideways 100cms from the edge of the panel.
The first pic is the response from the front  in that part of the room(peak hold).
The second is the same peak hold front responce but with the real time side response below (both averaged,because the dogs were going made waiting for mum to come home!).
Plus I was having to run into the music room to take the pics from the deq  before the 30 seconds of pink noise stopped and another test tone started and ruined everything !
It all ended very quickly when my wife came in and said (turn off that horrible noise!)
Those are 5 db segments on the deq and you can see the HF shelf above 10k when measured from the side.
You can also see the 100 Hz or so suck-out, which changes frome short and deep to shallow and long from 100HZ to say 300HZ, depending on room positioning and room.(big problem!).
I am very impressed with the full range ability of the panel but it is very room dependant between 100HZ to 300HZ ,this can make the panel sound thin in the lower midrange .
This is why I have talked about filling in with a 15inch driver or xover at say 200HZ to save the panel from room problems.(that’s if room treatment doesn’t work).





Sorry if this is a bit rag-tag but I hope it helps.
sedge

 

[sedge]

somehow missed the post on page 67 by tommus ,you guessed the poly struts ,very good ,sorry no prize.
what is your impression of the sound of the hard plastic glue and the pva.
which do you think sounds more natural.
how are the big panels getting on.
sedge

[sedge]

oops this should be the second pic!

get it right