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

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zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #960 on: 4 May 2010, 08:18 am »
Besides the fact that I have often been a total ass on more than one occasion,(sorry about that.......male menopause?? :lol:) I would like to inform those out there who are still watching  this page as I am, :peek: that the EPS has been worked with furiously over the past ....................nothing has died in this technology and my efforts to make it work.............I have made the odd give it all up comment in the past, but only very recently has a breakthrough been made :duh:

I type this post listening to a panel in my study to the right of me, making some of the best sounds yet heard using NXT technology and simple exciters!!!!!!!!!!!     8)

I have a GAINCLONE chip amp running these panels to stunning levels of fidelity and SPL! :rock: :weights:

Don't for an instant(never ever! :nono:)underestimate what kind of amplifier to use with a certain type of speaker.I have found this out the hard way...........lots of wasted time and pure frustration, blaming the NXT format as the cause of the downfall to all the varieties of materials and configurations tried..................................IDIOT!!!!!!!


I believe that I am so close(if not already there :D)to nailing this S.O.A.B. that it's soul enriching  :eyebrows:

I will clearly state that I have recently given you a hint at what works and what doesn't?????................hang in there: children of the vibrating round funny thing..........it'll be worth it 8)

These things will be able to be made for practically nothing.............the original goal from the start.

There are a couple of tricks to make them work................they sound VERY different to cardboard, Gatorfoam and the rest.............they sound BETTER!..........much more efficient and much more highs..............what we wanted?

Are they perfect?........................show me a speaker that is :green:

I'll put it this way...............the NXT panels have been in a shoot out only yesterday............ with open baffle speakers...............quite a few of them............Lowthers, Visatons, Tangbands, Fostex and a couple of cheap no brands...........some were augmented with 15 inch low frequency woofers.

VERDICT?....................HAHAHAHAHAHAHAHAHAH AHAHAHAHAHAHAHAHAHAHAH.........HA! :icon_twisted:

scorpion

Re: NXT.......rubbish??....THINK AGAIN!
« Reply #961 on: 4 May 2010, 02:38 pm »
Hi Zygadr,

I suppose I could threathen to publish a picture of 'The Old Man and the Black Monster' as I have it for my own really good memory from last autumn (sorry my autumn, your spring), did you enjoy the wine ?  But I realized that I would never be able to get any GATORFOAM board up here in the Nordic Countries without ordering it myself to outragous cost. So just let it LOOSE EVENTUALLY. You have been leading this pack all the way, my exciters are still in their packing box. I will let it loose on your command and with your guidance. Regarding the OB shoot-out  I have questions. Releasing my picture on the forum was one of my ways approching you, in fact.

/Erling

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #962 on: 5 May 2010, 01:09 am »
Hi Erling, the wine was great!..........thank you for that! :wine:
By the way, your picture is a very good likeness of you :)
''Old man?''...............oh,my!...........people have said that I look young for my age!  :jester:

I'm not knocking the other open baffles in our very rough and quick shoot out.........done in a tin shed of all places! :roll:..........they sounded great.......each had their benefits and downfalls as expected(the NXT's included).A ''T amp'' and Gainclone amp(not mine)were used as amplification, a NAD CD player the source.Music included jazz, classical, and popular.

The point is that the NXT's were right up there with them...................and remember, there were no tweeters in any of the full range driver/twin cone set ups.

What was common with the twin cone jobs was that ''shout'' in the mids(and some had modifications/foam etc. to minimize this) and a general lack in high frequency output.

Of particular surprise were the Lowthers :scratch:.........a fantastic sounding speaker, but only if you sit in the firing line, otherwise,the high frequencies are diminished - rapidly.

Another noticeable sound quality issue was the bass augmented speakers. One was open baffle, the other bass reflex.
To me, the open baffle bass did not sound right. Maybe I sensed the electronic components in the crossover that was needed to bring out the bass...............who knows?

With the bass reflex, ''box sound'' was annoying even though it had been done perfectly to plan.........go figure.

Now, the NXT's were not perfect either.
 They were quickly thrown together for the shoot out(so were some of the others!) without much consideration given to dampening the panels edges,(very important) so there was the occasional ''buzz'' heard.

Some mentioned a ''polystyrene sound''or tone that was slightly evident................I said that whatever the choice of panel material will be the overall sound of the speaker.........it's as simple as that. The same goes for any driver............the cone or diaphragm dictates the tonality IMHO.
 However, I did not agree that this ''polystyrene sound'' was very evident or offensive in any way. There were mixed opinions on this subject.

 The bass of the NXT's was massive and deep when called for...........everyone was surprised.
The highs were not lacking........especially when compared to what was in competition to them. No one mentioned anything negative in that department.

Where I was most pleased was the way they filled the room around themselves and their ability to produce those outstandingly fast and tight transients together with the details of what was being hit, blown, bowed, etc.....................typical NXT performance, but even more enhanced now with an ultra light panel.

Those of you you who have exciters unused or even in use, ................keep them!............we WILL beat this animal in to submission! :icon_twisted:(I think I already have?) :green:



Raintree17404

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #963 on: 5 May 2010, 02:11 am »
Zygadr - Please elaborate on your latest setup as I'd like to give it a try myself.  I too have amassed a pile of waiting exiciters to put to the task.

Without a positive design nudge I'm sticking with my personally sucessful very close nearfield system (listening at about 18" from panel).  It's better than any headphones in my book.  The sound is insanely good and very loud with a T-amp; guessing that the upclose bass reinforcement I'm getting at this distance is a key for me.  My multi 10"x30" (4 per side) gatorpanel test at 12' listening distance was way more than adequately loud with 2 PE T-amps, and the sound was still stunning in mid and high frequency ranges, but unfortunately tiring over time with the missing bass reinforcement at distance.  With family/children at home I have limited time for prototyping and I'm just not willing to venture much further than I have without the next best design I can mimic and maybe modify/improve slightly.  I know the larger panels are likely my fix for the bass issue, but what's the lastest/best overall design at this point (panel size, number of exciters per panel, exciter placement, method of attacment, etc...; with details being important)?  Do consider this a compliment for your efforts to date.  Fortunately I don't need to strive for WAF and can just aim for the "sound" because I'm only playing in my space at home. 

Also, I'm wondering about my PE T-amp on a recent mess up on a test of changing out versions of series/parallel wirings.  My T-amp didn't seem to care much that I had + and - wires inadvertantly crossed together on one panel???  The panel that I crossed didn't play, but the other panel on the same channel still did!  I'm not suggesting to do this, just that the PE T-amp may be very resilient to any load it is given.

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #964 on: 5 May 2010, 10:58 pm »
Raintree, look back on a few posts(reply no. 954) and you will see my recommendation on a wooden frame and back brace to hold a 6 X 3 foot panel............polystyrene or whatever.

It's simple and works.

Raintree17404

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #965 on: 14 May 2010, 02:33 am »
10-4 Zygadr

I'm now trying a 2' x 6' gatorboard set next, and will have the material on Monday.  The gator price is a bit salty for what has been an extremely low budget escapade so far.  What I have now sounds good enough small scale so I just can't help but try bigger.  I'd really like to try VH poly next as suggested but I can't seem to find the VH poly anywhere in my area, yet anyway.  I have to get the material local because shipping charges for large stock kills the deal no matter how cheap the material is itself online.  What offset from center do you use when arranging the linear alignment on a back brace?  I asume you: 1) set all the exciters on the board, 2) then attach the exciter magnet structures to the back brace, 3) then use globs of silicone to attached the board to the perimeter frame, correct?  I want to try 8 exciters per speaker and wire for my T-amp at 1 ohm (it works still so far, no amp burnout).  Am I moving backwards trying 8 exciters per speaker, and eliminating decent HF response?  I'm still theorizing that too many series connected exciters is what kills the HF sensitivity.

Nickolay V

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #966 on: 14 May 2010, 10:35 pm »
Zygadr

How  (! after your long time exploration and tests with various kind of materials) do you think what (! at present day) best for TRUE audio sound quality and  what size is optimal  for LF from 110-120HZ  ?
2)from 35-40Hz ?
Thanks!

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #967 on: 17 May 2010, 04:37 am »
Mounting method:
1.mount exciters permanently on to the panel(doesn't matter how far from centre....depends on how many exciters you are using) so that there are identical spacings from top of panel, bottom of panel and BETWEEN the exciters. work this out to scale on some paper first or you may be sorry :duh:

2. Now,...........place blobs of silicone on the corners and a couple of spots on the sides of the panel(exciter side of course)and lower the panel downwards on to the wooden frame. You can apply slight pressure on the siliconed areas if you wish.
Make sure the panel lines up with the smaller frame area underneath.

3. let it dry over a day or so.

4. Lift the panel up vertically and use some form of method to hold it upright firmly.

5. Work out your brace height and mounting holes(should be pre-drilled and ready)so that the brace can be secured easily.

6.Place silicone blobs(high enough to make contact with the brace when it is positioned behind the exciters)on to the back of the exciters.
Position the brace with screws ready, against the exciters, ensuring that a good contact is made between the exciter and brace and screw the brace to the frame..top and bottom.

When the silicone has cured, the panels are ready to use.
Any downwards drop of the panel will be equallly supported by the silicone when in an upright position.

I do not know what or if any problem would arise if the panel leans back?

To obtain 110-120hz bottom frequency response, only a small panel of approximately 1 foot X 2 foot (maybe smaller) would be sufficient.
35-40hz ??............8 foot X 4 foot..........but this will be wobbly and unstable due to it's large size.Can't say that this would be a good idea :nono:

Nickolay V

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #968 on: 17 May 2010, 08:26 am »
Thanks Zygadr!
But first of all I want  ask you about what kind of materials (by you tests) best and preferable :Gatorboard/Cardboard/HV polysterene/any honeycomb materials ?
What about "mother-of-tone" in  material that you chose finally ?
 

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #969 on: 18 May 2010, 01:23 am »
Mother of tone?..................unfortunately there is nothing available except corrugated cardboard which is o.k but has it's problems and really weighs too much when using 2 ply sheets of large size.

So far, the best panel material has been ''hard grade'' polystyrene foam. It too is not perfect and suffers from lack of true rigidity, but is extremely light................so, .............it is very efficient in SPL and the transmission of highs.

The other tricky part with polystyrene is that it has to be damped at the edges to stop it from ''buzzing''. Where the silicone is placed is very much experimental to avoid buzzing noises.

Nickolay V

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #970 on: 18 May 2010, 12:33 pm »
Dear Zygadr, thank you very much for your answers!
We've been testing several brand name NXTs:
1)Wharfedale Loud Panels
http://www.google.ru/search?hl=ru&lr=&newwindow=1&q=Wharfedale+Loud+Panels&aq=f&aqi=&aql=&oq=&gs_rfai=
(At seems to me that they use Polystyrene in these!?)
2)Carlsbro nLIGHTn
http://www.google.ru/search?hl=ru&lr=&newwindow=1&q=Carlsbro+nLIGHTn&btnG=%D0%9F%D0%BE%D0%B8%D1%81%D0%BA&aq=f&aqi=&aql=&oq=&gs_rfai=
Specification says these are made of Phenolic Paper Membrane on Honeycomb Composite.

Both sound amazing (better than any audiophile grade "piston" loudspeakers), however the latter are more sensitive and expressive.
Both work perfectly well at 140-150 Hz (! with subbas). Both are made in China.
Not long ago, we emailed our Europe Carlsbro representative, asking them to inform us about the Chinese company that produces  this Phenonic Paper. We’re still waiting for their response.

And as next step we plan to test Amina Pro NXT    http://www.aminatechnologies.com/speakers/acpt-prod.html.


What do you think about this all ?

PS.    Russian main conf. about NXT  http://forum.ixbt.com/topic.cgi?id=12:44450-18

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #971 on: 19 May 2010, 12:47 am »
What do I think of all this?..................... :lol:!!!!!!!!!!!!!!!

Closing the back of a panel(in the wharfedale and Amina systems) defeats the purpose of the whole principle.........so does using a sub woofer  :roll:

NXT once provided me with prices on Phenolic honeycomb panels made in China..............ridiculously expensive! :o................good luck with that one as they will most likely only supply to NXT themselves or large companies.
Freight is also a problem due to the size of the sheets.From memory, I think the honeycomb sheets were NOT covered with any ''skin'' on the surfaces?..............another problem :duh:

Nickolay V

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #972 on: 19 May 2010, 10:58 am »
Many Thanks Zygadr !

And  will it be SIGNIFICANT differences  "mother-of-tone" quality (! realism ) between  Phenolic Paper Honeycomb and High Density Polystirene ?
Or not  noticeable ? Practically without differences ?
          By your experience and opinion.
« Last Edit: 19 May 2010, 05:37 pm by Nickolay V »

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #973 on: 20 May 2010, 12:08 am »
They both have a sound of their own:

Cardboard sometimes sounds like a cardboard box that is being hit...............it is not perfect.

Polystyrene has a ''brighter sound''..................I wouldn't consider this neutral either.

If there was a perfect panel material, I would like to know what it is because even the mylar coated honeycomb has a ''character'' to it. :scratch:

grantnsw

Re: NXT.......rubbish??....THINK AGAIN!
« Reply #974 on: 21 May 2010, 03:25 pm »
 :scratch:  :oops:
I haven't read much of this thread, but I'm wondering if these are good?:

http://www.soundlabsgroup.com.au/c/Visaton-Exciter/Panel+Exciters.html

if they have been considered before, yikes, silly me...  :duh:


zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #975 on: 22 May 2010, 05:39 am »
They have been spotted and mentioned on another forum if not this one.
Basically, same thing as the cheap exciters, but cost more due to brand name and cosmetics change.

The second one(BS-76) however, still has me intrigued :scratch:

panomaniac

Re: NXT.......rubbish??....THINK AGAIN!
« Reply #976 on: 23 May 2010, 05:58 pm »
Sooo.... Polystyrene panels.   Are we talking about (heaven forbid!) "Styrofoam"?
Like they make cheap beer and bait coolers out of?

Or is it something else?

zygadr

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #977 on: 24 May 2010, 01:35 am »
''heaven forbid''??????????????????????

Yeah, you're right...............................get Japan to make you a panel out of burnt coconut fibres dipped in the juices taken from Adriatic virgins boiled in peach wine and dried in Cedar panelled sheds situated on the highest mountains on top of the valley of depression.

emailtooaj

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #978 on: 24 May 2010, 03:09 am »
Waiting for my final coat of epoxy to cure on my polysty panel. I picked up a 2x8 DOW 60 panel and cut em down to 2x4, and WOW. I seems very very optomisitc!! They are 1" thick and I don't think the thickness will matter? When I did a quick test I was able to get highs and low FQ very clear. After my first (very very thin) coat of epoxy, that seemed to make it even a bit louder and more uniform. I'm using my 2nd coat to glue on the exciters. That should hold them in place through all the torture test I'm gonna put them through. Will keep everyone up to date on progress if anyone is interested?! :thumb:

panomaniac

Re: NXT.......rubbish??....THINK AGAIN!
« Reply #979 on: 24 May 2010, 05:49 am »
I was joking you know. ;)

So, is it Styrofoam?  Or something harder to find?