[emailtooaj]

I'm certain that i will get what is in the highlighted area of the chart....


Typical Strength Characteristics -
EPS Thermal Insulation Board Property
Units ASTM test ASTM C 578 Type I VIII II IX
Density range pcf C303 0.90-1.14 1.15-1.34 1.35-1.79 1.80-2.19
Flexural Strength psi C203 25-30 32-38 40-50 55-75
Compressive Resistance -
at yield or 10% deformation psi C165 or D1621 10-14 13-18 15-17 25-33


Here is the link to EPS Molders, you can also find suppliers here in the States...
http://www.epsmolders.org/4-ftc.html

[zygadr]

3  lbs??????????????????????????............what the hell does that mean?

You did not look hard enough on the Foam Sales site for EPS:

http://www.foamsales.com.au/uploaded/files/client_added/EPS%20Technical%200807.pdf

VH GRADE is there!

SPECIAL! ..................SHEETS ON SPECIAL THIS MONTH ONLY FOR $999.00 U.S. each from : ZYGADR NXT PRODUCTS..............hurry before they're all gone!

That information will cost you a bottle of fine ''Polish Vodka''.....thank you!

[jonners]

3  lbs??????????????????????????............what the hell does that mean?

Presumably it means a density of 3 lbs/cu.ft. Your VH grade has a density of 28 kg/cu.metre, which is equivalent to 1.74 lbs/cu.ft.
So it looks as if the density range that emailtooaj has highlighted (1.80 to2.19 pcf or lbs/cu.ft. ) is the closest to the VH grade.

[emailtooaj]

jonners...
Thank you for clearing that up
I was a tad tired when posting that(damn 60hr work weeks ) sorry I didn't elaborate more.
Yes, They call it 3 lbs. density(rounding up I assume).
If the panels eqaul out to 2.19 lb density, that would translate to 35 kg/m3.
Slightly more dense than the 28 kg/m3 - VH grade EPS Zygadr is using.

Here in the U.S. this is how they classify EPS....

.5 lb. = Type I- .9 to 1.14 lb/ft3- 10 to 14 psi
1.0 lb. = Type VIII-1.15 to 1.34 lb/ft3- 13 to 18 psi
2.0 lb. = Type II- 1.35 to 1.79 lb/ft3- 15 to 17 psi
3.0 lb. = Type IX- 1.8 to 2.19 lb/ft3- 25-33 psi

I am in the process of ordering 16 panels . All will be 2'x4' dimension and 1/2" thick.  3.0 lb density (or 1.8-2.19).  Even if the EPS only comes out to be 1.8 lbs/ft3, that would still be identical to what Zygadr is using. So we'll see if more density with EPS panels is truly better?
I'm going to request a spec sheet on my order, and verify the exact density the panels where made too

I hope this clears up some of the earlier confusion.
Now off to my second job....

[cologner]

As far as I could research over here, 30 kg/m3 is somehow the max for EPS sheets, and it depends on temperature what the panel is physically able to perform...
Will place my orders on Monday and I think the little Dayton amplifier will do a good job with 2 exciters per channel. And this unit can work with battery power also
Hm take you EPS panels, Ipod and amplifier to the lake and have a nice day with your friends, sounds like fun

[Raintree17404]

cologner  -  I have been using the DTA-1 into loads as low as 1 ohm without issue.  The amp plays its little heart out until you push it too far and then just cuts out with no damage.  Just lower the volume and it resumes operation.  I am still amazed at the volume the DTA-1 gives on panels with multiple exciters.  Over the recent holiday while I was away from home I ran the DTA-1 24/7 at three quarters volume for 3+ days to see if the amp has a burn in effect.  I can't say I've heard a distinguishable difference.  I can tell you the preamp/headphone source makes a big difference.  Connected to my laptop the sound is absolutely stunning, and from my mp3 player just very good.  Currrently I'm running 8 of the cheap exciters ($5/pr, 4 ohms each) per panel.  4 wired in parallel, in series with 4 wired in parallel.  The 8 is a little louder than the panel with 4 (all in parallel), but my panel with 8 is slightly larger.  The 4 per panel is probably the way to go (my recommendation: all wired in parallel if using DTA-1).  If someone in the US ID's a reasonably priced, small order, VH grade board source I'll gladly try this over my gatorboard to hear the difference.  Gatorboard by no means is a slouch for sound.  The larger panels (i.e. 2 ft x 6 ft) have decent bass, just not pound your chest bass. 

[zygadr]

Guys, you will find that the VH will wipe the floor against all other panel materials - especially in the loudness department.

The digital amps will be a very good match with these NXT panels..............I had a SURE 2050 board working a few months back until it decided to mysteriously go up in a mushroom cloud of smoke

If you think class D sounds good, try a SUPER version of the GAINCLONE as I have built : ultra high quality resistors, IXYS bridge rectifier, and Black Gate filter Capacitors, silver wire, and stepped attenuator.

Bass is cavernous, sound is so open and incredibly dynamic. A great match if anyone is thinking of building againclone for the NXTVH's

[j gale]

So far haven't found a source for VH grade or equivalent. Perhaps if we knew the primary or most common use for VH grade it would help us find some here.

[Nickolay V]

Hi Zigadr !
I also try connect my Carlsbro nLightn NXT speakers with various amplifiers.
Best results also took place with class D amplifiers.
Hypex UcD and especially  Flying Mole.

I search VH EPS in Russia , but still not found.
What do you think about  these exciters:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-377
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-378
How do you think , what frame must be for 75x185 cm Panel :wood (what kind) / metall(inox/Aluminium)  ?
And what about frameless ceiling wire ropes (! 2 ropes) suspension ?

[zygadr]

j gale, the VH grade is a stronger compressive strength/density version of your standard poly beer cooler material. It's just a harder, more rugged version that will probably be found in the building industry where it is used for insulation in walls, roofs and even under floors.

If you are asking around for expanded polystyrene, insist on what is available that is the strongest and highest quality.
It may even be found in the sign making industry where letters are carved out of large blocks.

When you place normal and the high grade side by side..................the difference is obvious. the standard stuff is soft. The higher grade is harder, sounds louder and crisper when handled and has a fine cell structure along it's edges.

Nickolay V................both of these exciters are fine, but the first needs to be supported by a separate structure or brace away from the poly it is adhered to. Otherwise, it's weight will just tear off the mounting and probably damage it's own voice coil.

The cheaper exciters are just as good and the extra expense of the two exciters you have links for are, in my opinion, not worth it.

With amplification and NXT, there is no ''free lunch''.
Theses panels need at least 30 decent watts per channel with good current delivery.

Forget SET's unless you have some giants with ancient transmitter valves running on 2kv!! ..................I know this because I have tried a number of single ended amplifiers booth valve and solid state and they're good up to a point, but to make the panels really sing and produce their marvellous attributes, MUCH more power is required.

As I have said, the GAINCLONE a.k.a. ''Gaincard from 47labs'' is a match made in heaven

[cologner]

j gale, the VH grade EPS I could find over here is insulation material for construction work (1 cm of EPS has the same thermal value as 66 cm of armored concrete! ), or for model making (modeling foam). In both cases it´s a good idea to contact the manufacturer, I will get 2 sample panels grade 30 (which is density 30 kg / sq.meter) for free because they want to see what I´m doing with it
Raintree17404 , good to hear the DTA-1 is such a good amplifier. I´m using the Onkyo Integra A-8870 and don´t dare to connect it to these exciters...
The cheaper 5$-exciters will probably be too expensive for me because I have to add shipping and maybe customs dues.

I have two other questions concerning exciter positioning and possible stereo effect on a single panel. Do 2 lines of exciters (equal in distance to each other and the panel dimension) make sense, anyone tried this?

[jonners]

cologner -

If you look back at p.37 you will see some comments by pol_bct about single panel stereo.

[cologner]

cologner -

If you look back at p.37 you will see some comments by pol_bct about single panel stereo.

I read his suggestions before, but the setup is completely different from what I was asking and showing in the picture. POL talks about single rows and exciters close together, my idea is double rows with exciters equally spread in distance (as zygadr claims for exciter positioning), on a bigger panel.
Question is in general, do double rows make sense, even if you don´t want to go Stereo on a single panel.

[Nickolay V]

 Zygadr

And  ......How do you think , what frame must be for 75x185 cm Panel :wood (what kind) / metall(inox/Aluminium)  ?
And what about frameless ceiling wire ropes (! 2 ropes) suspension ?

[zygadr]

Frame should be wood........preferably Cedar.Do not use metal.............it might start ringing.

If you go frameless, try the fishing line suspended from the ceiling method described in Audio Express magazine many moons ago.
However, what concerns me with raw EPS is that the edges  need a little dampening, so the frame idea is a better option IMHO.

[zygadr]

Have been listening to the unmounted panels with the Gainclone(upgraded again with better parts still) and can not believe what I'm hearing.
Now that the Black gate capacitors have ''charged up/re-formed'' or whatever ...........the extent of musical information and the great slabs of detail are truly jaw dropping ..........have NEVER heard the panels sound like this..................amazing!

Bass?..................Bass?..................oh man!!!!!!!!!

[zygadr]

So, looking for timber for the frame work (spruce/pine/cedar..whatever ) at the local giant hardware stores.
Not interested in dark wood...........needs to be a blond wood.

Everything has knots in the worst places(right in the middle)and the lengths look like bananas!
Total crap!....................will need to go to a timber supplier and stop the B.S. with these losers and their crappy timber

To top it off, they don't like you sorting out the better lengths(even if you intend to put them back!) and even tried to tell me off! ...............my response was predictable - ''get stuffed!..........I'll go elsewhere ............dipshit''!

Luckily, my wife's uncle runs a major timber supply business...............I can't call him a ''dipshit'' and get away with it

[cologner]

Hi zygadr, this is the same problem over here, don´t look for timber, look in in the interior decoration dept. or art supply and get your wood strips right there.
My idea is: find some balsa wood strips for your frame work. Did you know that lightweight balsa wood is as dense as EPS? Best combination in my opinion. Alternative is cottonwood but sometimes hard to find. The balsa stuff is cheap and easy to handle.
What size of frame will you use if your sheet is 185 cm X 75 cm, and what kind of adhesive to mount the frame on the sheet?

[zygadr]

Hi cologner,thank you for your advice.
There are a few problems here unfortunately : balsa wood is only available in short lengths and even when glued, it's bent all over the place and not rigid enough.

The idea of the frame, as Podium Speakers mention, is that the frame must be able to rigidly hold the panel in place and vibrate with the panel only in a constructive way(not creating further resonances) and still dampen unwanted sounds.

I'm afraid that balsa is not the wood of choice.

I have since found excellent quality pine lengths : 140mm wide, 18mm thick and 2400 long.
They are as straight as an arrow (well.........nearly ) and have no knots or other faults.

I will get these cut to size this weekend.
Now....................how to join them?

[emailtooaj]

Good show Zygadr 

would you mind posting pics when you get finished?