NXT.......rubbish??....THINK AGAIN!

Nickolay V · « **Reply #1140 on:** 24 Sep 2010, 07:40 pm »

Hi Zygadr !
Is there any success with you big size XPS panels ? You promised some photos of it. I'm eager to see them.

zygadr · « **Reply #1141 on:** 28 Sep 2010, 07:55 am »

What's to see?................two big white panels in a pine frame.

They work and work very well.

Here's a secret.....................be very very careful what you use to bond the panels to the wood with!.................remember, lots of constant vibrations are cruel to rubber adhesives tapes etc.

irishpatrick33 · « **Reply #1142 on:** 30 Sep 2010, 05:56 pm »

Quote from: zygadr on 28 Sep 2010, 07:55 am

What's to see? two big white panels in a pine frame.

They work and work very well.

Here's a secret be very very careful what you use to bond the panels to the wood with! remember, lots of constant vibrations are cruel to rubber adhesives tapes etc.

I think it is a fair request ziggy. You started all this and still continue to advise. Yet you refuse to show people the finished product? Seems very odd. It's just a few pictures.

Furthermore, your comment doesn't make a whole lot of sense to me. You have your panels bonded to the wood? I was under the interpretation the goal was to keep the two decoupled. This is why pictures are often more helpful. Then we can see with our own two eyes instead writing that is: sometimes hard to understand, vague, and incomplete.

sedge · « **Reply #1143 on:** 6 Oct 2010, 06:39 pm »

Ragna
Sorry for the delay in replying, works, work, work!
I have been experimenting with some 40x40 cm sample panels I was sent as per zygadr ‘s spec.
The sound is very good and I would recommend anyone to try it .
I have used 30cm ceiling tiles and used tin foil ,thin ali sheet and paper ,the main problem with these is gluing them to the panel plus will it stick ? will it stay stuck ? And will you like the varying sound they bring ,so far, I prefer listening to them naked( the panels not me)

sedge

ragna · « **Reply #1144 on:** 10 Oct 2010, 08:44 am »

Hi sedge,

gluing some layer (alu or cotton) might be a problem, but the sound is currently one.
In Germany I found to EPS (expanded) , one with pearls <1mm (almost homogeneous) and one with pearls <5mm (it crumbles when you break it). I think the second one is the right.

I bought 2 qualities, 16kg/m2 and 22kg/m2
(http://www.modulor.de/shop/oxid.php/sid/ce0436b48b9fd8a96ddfa184f16a84b8/cl/details/cnid/ABA/anid/ABAB/tpl/-/lang/1/listtype/list).

The measurement was ok, hf<10kHz, but the sound was really bad. It was hollow, reverberant, like in a naked room. Damping as not enough. I glued a cotton sheet on the EPS and it was good (silk might be good as well or Microwood (http://www.modulor.de/shop/oxid.php/sid/ce0436b48b9fd8a96ddfa184f16a84b8/cl/details/cnid/CPK/anid/CPKD)).

My questions: is the EPS with 5mm pearls right and will the increase of density from 22kg/m2 to 30kg/m2 (ziggys VH EPS?) really result in a good sound? For me, hard to believe, to be honest. I already would have tried the heavier EPS, but it is difficult to get.

But the effect of a stereoscopic or holografic (or what it is called in English) sound. almost independent from the listening position, is breathtaking. It makes fun.

sedge · « **Reply #1145 on:** 11 Oct 2010, 12:05 am »

Ragna
The smaller beads make the higher density panels(30kg/m2),these panels have good self damping and sound very good.
A good test is to play some loud music with high dynamics .then press the pause and then play, again and then again.
If you have the low density styrene (large beads)you will hear a whoosh sound as the panel keeps on producing sound after the music has been turned off.
The same thing happened to my plywood panels.
But when I damped the panels in various ways, the panels not only became less efficient but also lost a lot of the micro detail to the sound!!
If you like the holographic sound of the panels I suggest you try this experiment-
If you turn the panels so that they are almost facing each other the sound seems to come way back behind the panels into another room.
If you then slowly start turning them back to the front again you will find the optimum position for best all round sound.
One of my friends was so impressed when I Faced the panel towards each other that when I said I am going turn them back again he said no and insisted on listening to them like that all night.

Have fun
sedge

ragna · « **Reply #1146 on:** 11 Oct 2010, 05:09 am »

Hey sedge,
thanks for making this point clear. Then there is hope...

The smaller beads makes a homogeneous material, maybe it can be used as a screen for a beamer. It is easily available as extruded PS, but not as expanded PS. I will start with a research.

For smaller paneels, thinner (5mm, efficiency) EPS might be better)? btw, I talked to ELAC. They claimed for there Exciter an efficiency of 88dB/W for a 600g/m2 Material (honeycomb). Price for 4 samples 200€! Complete datasheet on there web site (www.elac.com)

sedge · « **Reply #1147 on:** 12 Oct 2010, 11:36 pm »

Strange that Elac only show the frequency response of an unknown sized perspex panel with a sloping FR of almost 10db from 200hz to 15k and using more exciters makes it even worse .

this panel obviously has problems,hence the electronic FR correction

sedge · « **Reply #1148 on:** 13 Oct 2010, 10:54 am »

You would think they would all be keen to show the FR of the fantastic honeycomb panels,
They say that the honeycomb has heavy paper bonded to both sides, this does not sound good to me (pun not intended ).
Podium state that their panels will not measure well under normal measurement tests ,I would still like to sea these tests if only to give me an idea of what is going on .
As for the poly panels ,they seem to measure quit well.

sedge

zygadr · « **Reply #1149 on:** 19 Oct 2010, 03:34 am »

Quote from: irishpatrick33 on 30 Sep 2010, 05:56 pm

I think it is a fair request ziggy. You started all this and still continue to advise. Yet you refuse to show people the finished product? Seems very odd. It's just a few pictures.

Furthermore, your comment doesn't make a whole lot of sense to me. You have your panels bonded to the wood? I was under the interpretation the goal was to keep the two decoupled. This is why pictures are often more helpful. Then we can see with our own two eyes instead writing that is: sometimes hard to understand, vague, and incomplete.

Panels have been removed from frames...................lousy carpentry job by myself caused issues in loud and low frequency music.......................so, ......................no pictures...................

............yet.

Next frame will be from solid sheets of MDF with a square hole cut out to accommodate the EPS panel size.

However, I will be trimming the width of the panels by at least 3-4 inches, otherwise they will be way too wide.

The panels were never ''BONDED'' to frames................they were decoupled by silicone sealant which eventually failed...................why?.............dunno

!!!.........may have been a dud/old/out of date tube(very likely)???

The next configuration will have the EPS ''suspended'' inside the frame opening rather than in front of it.
Method of suspension will be with elastic bands or something along those lines.

Lastly a black, speaker cloth ''sock'' will cover the entire assembly a'la Magnepan.........with the same type of feet. Only difference is that the panels will not be tilted back...........they will be vertical.

Nickolay V · « **Reply #1150 on:** 12 Nov 2010, 03:45 pm »

We preorder 5mm Rohacell31 from Moscow representative and will test 62,5x 125cm panels very soon. Its will be 4 exciters speakers. Full damped along perimeter.

Bruce Schlein · « **Reply #1151 on:** 14 Nov 2010, 12:26 am »

I have had a number of good speakers in my system including a pair of Dahlquist DQ 10's, a home built open baffle system and I currently own a pair of Linkwitz Orion 3.2's These are the most realistic and musical speakers of all that I have owned. They are not frequently reviewed but really need to be heard.

panomaniac · « **Reply #1152 on:** 14 Nov 2010, 04:15 am »

Which are? The Orions?

Bruce Schlein · « **Reply #1153 on:** 14 Nov 2010, 02:12 pm »

The Orion 3.2's are speakers I think are the best I have heard. Sorry for lack of clarity.

panomaniac · « **Reply #1154 on:** 14 Nov 2010, 03:48 pm »

Thanks Bruce - that's what I thought you meant, but wasn't certain.

trucker · « **Reply #1155 on:** 17 Nov 2010, 12:19 am »

Hi
I've just completed two panels, EPS, 60x120 cm, mounted in frames, 2 Parts express exciters wired in parallel. I have yet to try my new amps on these.
I'll try to post some pictures and comments later on.

zygadr · « **Reply #1156 on:** 2 Dec 2010, 04:05 am »

Stay on track guys....................

Hard grade EPS, 6 foot X 2 foot X 10mm panels suspended within a wooden frame ( using adhesive cloth tape, rubber, whatever).

4 X 8 ohm exciters wired paralell then series to end up with 8 ohms.

It's not hard..........................just FORGET the rare, expensive, hard to find exotic panel materials.............you are wasting your time

sedge · « **Reply #1157 on:** 9 Dec 2010, 07:57 pm »

Zygadr ragna
Ok I have to admit to getting side tracked again (in a good way) this time by my reply to ragna.
Because of all the experiments I have done with different panels and damping, I thought maybe I could use the 25 mm thick panel as a midrange unit (300 to say 8k) as the fr would be very poor and use a tweeter for hf.
Also the self noise would have to be dealt with in a way that would not over damp the sound.
I had an old battered 18inch by 4ft panel I had use for testing metal and paper coatings and the like.
The idea was to make a panel that was cheep and easy to get hold of without having to buy half a ton of poly panels(at great expense) just for a pair of 2ft by 4ft panels.
If this could be done then everyone could try the cheep version first to get to understand what they are missing without spending the money!
I can tell you I was very surprised when I fired up the panel (no tweeter)hf up to 16k and only down a few db at 20k and the sound was very good indeed .
I will give more details later as I have to work again(out of time) so must be off
sedge

sedge · « **Reply #1158 on:** 17 Dec 2010, 12:45 pm »

Giant killer panels

OK, Sorry for the delay, it’s that time of year.
I have had some friends over to listen to the panels to get a second and third opinion of the sound.
I trust their judgement, and new if there was something wrong they would let me know.

I had to move the panels to my living room as the listening room has a 100 Hz to 300 Hz suck out which made them sound cold, normally I use a Lf driver to blend in below 300Hz.
I set it up with an old cd player ,a t amp 2024 (less than £30 on the internet)one of the friends had lent me to listen to ,powered by a 12 volt 1 amp printer power supply .
So this is going to sound bad is’nt it……..,wrong .
Comments such as – there is so much more spatial information ,you are in the studio with then playing real music ,live!
At a previous listening session comments about the echo (ragna mentioned echo as well)was mentioned ,not sure if it was real echo or the panel?
At the latest session it was confirmed that we were listening to the echo machines ,If you were a sound engineer I think you could easily play NAME THAT ECHO MACINE.
On a bog standard speaker you would not hear this .
Some may say this is too much information,I say engineers will have to pay more attention to what they are doing as we can now hear everything they are doing
The last comment on the last 3 hour session was –
Once again you have done everything wrong !
You are using a cheep old cd player a cheep t amp with a printer power supply, crap power cables,crap bell wire for the speakers ,and the panels are hanging from lamp stands .
But they sound better than anything I have heard at audio shows costing £10 k or more!……can I have some exciters?………NO!

panomaniac · « **Reply #1159 on:** 18 Dec 2010, 02:16 am »

Very cool, Sedge!

Can you recap your setup for us? Size of panel and material, number of exciters and type, etc. Thanks.