[DanTheMan]

So what's happening around here?  No one still interested in this technology or are there plenty of experiments going on behind the scenes?

Dan

[zygadr]

Dan, I promised myself that I would not post again on this thread due to the personal flaming and insults I have received via private emails from'' one off unknown posters''. On top of that, It dawned on me that there were only a few who actually did in fact experiment on their own and contribute to furthering our knowledge in regards to this technology.

There are many who just lurk and expect everyone else to spend their hard earned cash and countless hours so that they can benefit from or criticise someone or something they know F.A. about.

Regretfully, I have been dissapointed in the ridiculous directions that this thread has derailed itself towards.......................I set out to have an affordable Podium clone,succeded in doing so and then watched as others complicated and skewed towards non relative ideas and configurations that caused confusion instead of progress.

Yes, there IS action behind the scenes - lots of it ..........trust me..........some serious discoveries have been made ...........one we would never have thought of, as we have been looking blindly at ''composites'' and have neglected the obvious simple possibilities.
I'm not just refering to C.C...................there is another...............one of great interest to me personally from my recent experiments.

My thanks go out to jeffac, who has stayed with me and encouraged my efforts at the most difficult periods where I have questioned whether all this has been worth the stress and deep dissapointment over this lengthy thread that made me remove my posts in anger and frustration.

I am not the kind of person to hold a grudge against anyone..........that is my nature.
For any further input from myself on this thread, there would need to be a course change to what was started and intended right at the beginning of this thread.

There is a great need to go back to basics and understand that we are trying to make progress towards finding a ''useful'' panel material............not ones that weigh a ton, are clad in metal and sound like crap...........''low SPL'' crap in particular.

[Tinnitus]

I haven't recieved my my exciters yet, bah.
I'd like to repeat a request to anyone with access to exciters and musical instruments.
Has anyone tried placing an exciter on  big drum/drumskin?, or any other resonant musical instrument such as the body of a cello, double bass, or violin?
Are the sound-boards in pianos thin? or thick?
These materials would certainly adhere to the 'Mother Of Tone' principle (although I confess I'm a bit sceptical about MOT myself).
I'd be fascinated to hear your opinions of the result if you do have access to any of these.

So what's happening around here?  No one still interested in this technology or are there plenty of experiments going on behind the scenes?

Hi Dan,
I'm still interested in this technology for sure!.
I'm pretty non tech savvy compared to some of the contributers to this thread, but still feel that I've got a valid contribution to make, despite any naysaying.
With the help of my girlfriend I've prepared a pair of fabric sheets which I intend to experiment with.
Sadly delivery of exciters from the US to me in the UK is taking quite a while, and it'll probably take quite some time for me to complete the rig for tensioning the sheets, but it's underway, the fabric side of the equation is finished.
I also have access to large sheets of good quality corrugated cardboard (bicycle shipping packaging) and since the consensus here seems to be that this is one of the best materials I will of course be trying some experiments with that!( I'll probably not bore this thread with those results, I'd just be replicating the work of others).
Some of the technologies linked to from this forum and others has encouraged me to consider pressurised (inflated)fabric structures as radiating surfaces, and the tensioned sheets that I intend to try are a first step toward this.
My efforts may come to naught but I'm approaching this as a fun hobby, I'm actually really happy with my hi-fi as it is!.
This approach may be met with disinterest or derision, and perhaps that's all it will turn out to deserve, but any ENCOURAGEMENT offered will be greatefully recieved, and thanks to those who have humored me so far.
I personally love reading the ideas posed here, whether they follow the 'established' approach or not.
Mad ideas?, BRING EM ON!, I for one want to read them.
And I'm certain most people visiting this forum (whether lurkers or serious experimenters/contributers) are unconditionally greatful to those who offer their ideas/results up for scrutiny.
I certainly am, thanks.

[gilbodavid]

zigadr i'm sorry to hear you've been getting some private abuse, there seem to be a type of person who will do this, as i have experienced before. u're input is of great importance as u are one of the few who has done a large amount of experimentation. i look forward to hearing all u're input. i have 2 pieces of cardboard in my living room to try with my exciters but haven't had the time in the past month. i am extremely interested in all the experiments being done, and i am feeling that there is tremendous milage in all of this, and am hoping that the cardboard will be as good as others have said. cheers, David

[j gale]

 I too am still very interested. Life is holding up experiments somewhat I am moving and for now that demands my time. For zygadr I would like to say that without your efforts I would not have experienced all the fun I have had so far.  I have come to believe that the potential for a real high end loud speaker is within reach of the DIYer. I am also dismayed sometimes by the people with a little technical knowlege wanting to criticize what they haven't heard. This is especially irritating when they could so easily hear what we hear for themselves. Also what they think they know often doesn't apply to a DML. This technology will move ahead---new and better exciters----and I hope that the one who finds the magic panel material will share!!!      Jim

[usp1]

Hang in there zygdar and ignore the flames. Haven't been able to do much experimenting lately myself. I still have my panels and I find that two is the best number of exciters.I have to confess that the HF roll off  has been a little disappointing even with cardboard panels. But I still think that for about $20 one can make a very decent pair of speakers with this technology.

I am going to try putting an exciter on a hollow body guitar to see how that sounds but I am not sure if it would be any different than 1/4 inch plywood panel I tried...maybe a bit louder because of the resonant cavity. Will report after I do this.

[Tinnitus]

I am going to try putting an exciter on a hollow body guitar to see how that sounds...maybe a bit louder because of the resonant cavity. Will report after I do this.

Cool!, I'm guessing that the hollow body will affect the bass at the very least (helmholtz resonance?), my meagre understanding is that this is how ported eclosures are used to re-enforce bass?.
Will the guitar still be strung?, if so that could be a unique sound!
I look forward to your thoughts.

[pol_bct]

Hello all,
who wants to compete for the most crazy design?

http://img710.imageshack.us/img710/1493/carton01m.jpg
http://img85.imageshack.us/img85/3036/carton02.jpg
http://img683.imageshack.us/img683/640/carton03.jpg
http://img704.imageshack.us/img704/1544/carton04.jpg
http://img704.imageshack.us/img704/8543/carton05.jpg

POL

[usp1]

I tested a single exciter on a hollow body guitar. I damped the strings so that there would not be any sound from them. I tried putting the exciter on both the front and back (at different locations). On both sides there was a steep rolloff below 100Hz and above 12 KHz. The SPL and the tonality varied with placement. I did not actually attach the exciter to the guitar but held the exciter against the guitar with varying degrees of pressure.

Over all sound was very pleasant but lacking the highs and lows as with the gatorfoam and the cardboard.

Just for kicks, I undamped the strings and the sound was quite unpleasant. Placing the exciter on the strings lead to emphasis on different frequency ranges as expected. A good musician could look into using an exciter directly on the strings and a frequency generator to create interesting effects.

[mikadosan]

 

[usp1]

   My effort at keeping the experimentation going 

[Tinnitus]

Thanks for trying that out usp1, seems like it was a worthwhile experiment if it sounded pleasant.
I wish my exciters would show up, I'm itching to play with them.
What were the volume levels like compared with any other approaches you've tried?
Your post (and pols)leads me to wonder if there's any milage in cardboard vessels (I know they've already been done, but I've only heard small/crude single exciter versions like the soundpac speakers).
Could a wood veneer or c/board helmholtz resonator be tuned to re-enforce desired freq's?
I wonder if a larger instrument such as a double bass would help with low freq's in the same way that larger sheets of c/c do?.
I really want to try an exciter on a bass drum.

Over all sound was very pleasant but lacking the highs and lows as with the gatorfoam and the cardboard.

Can I just check your meaning here for clarity, the guitar lacked the same H+Ls that the GF and c-board does?, have I got that right?

[usp1]

Thanks for trying that out usp1, seems like it was a worthwhile experiment if it sounded pleasant.
I wish my exciters would show up, I'm itching to play with them.
What were the volume levels like compared with any other approaches you've tried?
Your post (and pols)leads me to wonder if there's any milage in cardboard vessels (I know they've already been done, but I've only heard small/crude single exciter versions like the soundpac speakers).
Could a wood veneer or c/board helmholtz resonator be tuned to re-enforce desired freq's?
I wonder if a larger instrument such as a double bass would help with low freq's in the same way that larger sheets of c/c do?.
I really want to try an exciter on a bass drum.Can I just check your meaning here for clarity, the guitar lacked the same H+Ls that the GF and c-board does?, have I got that right?

The SPL was higher than my 2'x4' gator panels or my 30"x60" cardboard panel with a single exciter. The frequency response was about the same as the gator foam or cardboard. I think a larger instrument like a double bass may go lower because of the larger panel ( We already know that larger panels give better bass) and the larger cavity may give more SPL.

I wonder if the lack of highs is systemic to the cheap $5 exciters.

[DanTheMan]

I wonder if the lack of highs is systemic to the cheap $5 exciters.

My guess is that's part of it.  That and a suitably rigid and light material.

I just got some double layer cardboard and I now have four exciters.  So what to do with it?  IrishPatrick's design appeals to me the most, but I want to do something new.  The question is "what?".....   Time for billiards.  I'll rack my brain.

Dan

Oh, has anyone has a VC burn yet?

[pol_bct]

DanTheMan

>> and I now have four exciters.  So what to do with it?

try the second one, down the page
http://img694.imageshack.us/img694/1756/ambiosonic.jpg

two exciters at center (L+R) are very close together
and the two others are at extremes L & R
all that on one single big panel
enjoy...

POL

[ondesx]

try the second one, down the page
http://img694.imageshack.us/img694/1756/ambiosonic.jpg

two exciters at center (L+R) are very close together
and the two others are at extremes L & R
all that on one single big panel
enjoy...

POL

This is a stereo+summed center channel ! But it seems the panel itself is highly important in your case as shown on the previous picts !...

[pol_bct]

I was not aiming at being serious

But I did a LogSweep,  H2/H3 are at -40/42dB
http://img519.imageshack.us/img519/7743/ondulcarton.gif
not that bad for a piece of floating "carton"

Wave front is better than lots of more sophisticated designs
http://img408.imageshack.us/img408/6750/frontcarton.gif

BandPass with a sync RTA is 220Hz/15000Hz
http://img294.imageshack.us/img294/4597/cartonondul.gif
and 35Hz/15000Hz two ways, with BASSbox added

POL

[sedge]

Zygadr
Went to the Bristol hifi show at the weekend and  all the speakers I heard sounded bad in one way or another but there was a very interesting speaker called  The kiss made by Vienna acoustics ,it was using a coincident 18cm patented vienna acoustics flat spider cone midrange with a 2.5 cm silk dome tweeter  in the middle,the sound was good but putting it in a box probably killed it for me ! [no mention of dml,bml or nxt ?]

Metal panels might have low efficiency and thus low spl ,but that does not mean they are crap .so far they are the best sounding panels of all I have tested [I have not heard the gator panel and this might be better ?] but as you say low spl is no good to you.

So its high spl we want ,well for me that can only mean polystyrene [I can hear the F ing and blinding from here ] leak used it in their sandwich speakers and so did kef b139.
I have been playing around with different types ,shapes and sizes ,these can sound bad but with a little tlc they can be made to sound good [how good we will have to wait and see].When I get time I am going to go to the diy store to get much bigger panels.

The sound so far  is very fast and dynamic and very efficient[sounds to me like a horn].
The thing I also like about these panels is that even very low level sounds are produced loud and clear [not so good for my noisy valve amp].
Obviously hf  is going to be a problem[ something like shellac might help this problem as it did with cc?]
I have looked on the web and have found manufacturers using thin paper coated polystyrene with good results ?
I look forward to hearing everyone’s comments .
[where the hell did I leave those ear plugs!]
sedge
 

[Tinnitus]

Hey Sedge,
What thicknesses/sizes/shapes/configurations have you been trying with the polystyrene?.

Has anyone following this thread tried a single skin panel?, i.e. instead of a material like gatorfoam with both sides coated, a layer of thin polystyrene (or whatever) with a single side coated or laminated with a hard skin?.
Or perhaps a very thin sheet of alloy with a single side damped?.

[sedge]

tinnitus
have tried 1/4  ,1inch and 2inch mainly about 2ft size .
just got back with a 1200 x 600 x25 panel.well that was the size I started with .had to cut it in half to get it in the car ,I could tell you the story of the raving nutcase being blown around the car park finally ending up spreadeagled  across the front of someones car [as luck would have it they thought this was hilarious ] :oops:Im glad someone thought it was funny
will probably shellac a12inch circle on the exiter side as I did with cc and see how it goes?