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

Angaria · « **Reply #60 on:** 28 Aug 2009, 08:53 pm »

Quote from: zygadr on 27 Aug 2009, 04:28 am

Woooooah!!!..........HOLD ON TO YOUR HORSES GENTS!.......a lot of these modelling programs and application documents/patents are for panels that are held firmly or even clamped by all edges, such as hanging picture frames etc.This is the actual NXT original application design notes.

This is totally different to The freely suspended panel like the Podiums and my DIY project.

I do realize this is different than your approach - I'm just looking into related tech to see if there are some useful ideas. Also the Podiums aren't freely suspended.

doug s. · « **Reply #61 on:** 28 Aug 2009, 09:55 pm »

Quote from: longdrive55 on 28 Aug 2009, 07:07 pm

Quote from: FULLRANGEMAN on 28 Aug 2009, 06:35 pm
Quote from: doug s. on 28 Aug 2009, 06:18 pm
Quote from: FULLRANGEMAN on 27 Aug 2009, 05:38 pm
The Dayton DAEX25 Sound Exciter is in stock again at PartsExpress, same price $16,90/16,00 earch
http://www.parts-express.com/pe/pshowdetl.cfm?Partnumber=300-375
why not get the cheaper ones?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=309-148
doug s.
I afraid of cheap products, maybe he feels so. I would like to know whait is the best? The dayton or the other white cap exciter? Before buy anything.
Regards

In my opinion the cheap ones look just like the ones that Zygadr used. The numbers by the voice coils are similar, but not exact too. The only concern I have about the cheaper ones is that they are 4 ohm, which means a lower amp load if you try to parallel multiples of them together.

Of course I really don't know how much parallel vs. series connections affect sensitivity with this kind of panel driver. Does anyone know if parallel connections increase sensitivity as they do with pistonic drivers sharing a baffle? Also, if you parallel some together, but then have to series connect a couple of paralleled groups together, does that diminish any sensitivity gains you might have gotten from the paralleled exciters?

examples: say you want to run 8 exciters per panel - if you ran two sets of four of the 4-ohm iterations in series, each series would be 16 ohms; when you parallel them, you would end up w/8 ohms total load. do the same w/the 8 ohm iterations, and you would end up w/16 ohms total load.

if you ran four sets of series-paired 8 ohm exciters in parallel, you would end up w/4 ohms total load. do the same w/the 4 ohm exciters, and you have 2 ohms total load.

you could get tricky and run the 8 ohm drivers this way - two sets of 3 in series (24 ohms total for each set), and one set of two in series (16 ohms for the pair). run these three sets in parallel for a total of 6.86 ohms...

basically, you should be able to get pretty-much whatever final ohm walue you want w/multiple exciters of each walue.

doug s.

FullRangeMan · « **Reply #62 on:** 28 Aug 2009, 10:34 pm »

Dear LongDrive55,
Please see this Link supplied by ZYGADR http://www.colomar.com/Shavano/spkr_wiring.html about speakers connections, very useful.

Jim Griffin · « **Reply #63 on:** 31 Aug 2009, 08:20 pm »

Ziggy,

I have requested that System Solutions remove any link to my 'Near Field Line Array White Paper' from their website as they are in volation of my copyright on that material.

The only authorized link to the white paper is via the AudioroundTable website at:

http://www.audioroundtable.com/misc/nflawp.pdf

I request that those who wish to link to the white paper to use that link.

The addition of exciters to a panel in your speakers should yield additional gain as you suggest. I'm not sure just how much would be attained as I don't know just how the exciters couple to the panels so that they create additional energy to the panel. But if any individual exciter perfectly couples its impetus to the panel, then the increase in SPL would be similar to direct radiators and how they add to the overall output. Thus this would be 10 log N where N is the number of exciters used. As discussed in the white paper the other factor to consider is the impedance as you connect exciters in series and then parallel.

Jim

FullRangeMan · « **Reply #64 on:** 6 Sep 2009, 07:59 pm »

Congratulations Zygadr for your success in this project. I understand your tube amp have only 6W in 8 ohms, your NXT panel must have a very hi SPL/W/M then.
How many exciters do you are using now??
Cheers, Gustavo

gilbodavid · « **Reply #65 on:** 8 Sep 2009, 12:56 pm »

Ok Zyggie you've got me! I just ordered 10 pairs of the $5 ones to me in England! I am over-run with vital work to be done so I'll do this instead! thanks for your enthusiasm. I'm running Lowther horns and AR3a's at the moment with AR9's to be restored as well, but what attracts me to these is the Quads with dynamics and efficiency possibilities and the possibility of having them close to or even against the wall.

j gale · « **Reply #66 on:** 9 Sep 2009, 03:52 am »

I just want to say that I am using the $5.00 per pair exciters removed from their housings and they work very well. I think they are probably the same as the Daytons except for 4ohm vs 8 ohm for Dayton. I have a pair of 2'x6 ' gatorfoam panels (black) with 8 exciters on each 8" apart. 4 parallel pairs wired in series for about 8 ohm. Bass is very good and clarity is excellent. Presently just leaning against the drapes. I'm sure that if I can get them mounted in a frame without killing the magic that they will sound even better away from the wall. Since Podium and everyone else seems to cut the corners off for better sound I suspect that corners would not be good mounting points.

FullRangeMan · « **Reply #67 on:** 9 Sep 2009, 07:27 am »

Thankyou Zygadr for this impedance and break-in info. Here in Brazil I could not find an supplier for GatorFoam.
Ironically I found a supplier of CarbonFiber in Sao Paulo. Where you all buy GatorFoam in U.S.??
Zygadr what you do for NXT Company response your queries?? Already two weeks I question they for a NXT exciter and I have no response...
Is it because I live in Brazil??

j gale · « **Reply #68 on:** 9 Sep 2009, 03:04 pm »

Hi Fullrangeman, Gatorfoam is a product that has been around for years. Sign companies often use it for displays and signs. I got mine from a company that sells plastics such as coroplast. I believe you could order the exciters from Parts Express. They ship to other countries. I'm in Canada and mine came by mail. Hope this helps. Jim

FullRangeMan · « **Reply #69 on:** 9 Sep 2009, 07:35 pm »

Quote from: j gale on 9 Sep 2009, 03:04 pm

Hi Fullrangeman, Gatorfoam is a product that has been around for years. Sign companies often use it for displays and signs. I got mine from a company that sells plastics such as coroplast. I believe you could order the exciters from Parts Express. They ship to other countries. I'm in Canada and mine came by mail. Hope this helps. Jim

Thankyou Jim for your help. Could be fine if PartsExpress sell the GatorFoam panels too, I like the Dayton exciters they have.
I plan use eight Dayton exciters per panel, in a Serie-Parallel link for a nominal impedance of 4 ohms.
In my city there is a big raw speakers manufacturer that is NXT licensed. Around 1995 the speakers desinger of then buy the grade, now he is retired, no more in the company. Last week I phone this company and the current speaker engineer never heard of NXT, I have to explain to him what is NXT about, and he do not show any interest at all.
So this company do no one product with the NXT license that in 1995 cost arount 5K dollars, now look how far Zygadr came as a amateur!!!
Regards, Gustavo

gilbodavid · « **Reply #70 on:** 11 Sep 2009, 05:43 pm »

zyggy i shall definately use gatorfoam, size will be an issue so we'll see. J Gale are your exciters in a line up the middle of the panel like zyggy's? cheers, David

j gale · « **Reply #71 on:** 11 Sep 2009, 08:06 pm »

Hi gilbodavid, Yes I used 8 exciters on centre 8'' apart. My panels look just like Ziggy's picture of his. I chose 2'x6' because I have a smaller room and could get 2 panels from 1 sheet of gatorfoam. I suspect that slightly bigger or smaller won't make much difference. Very impressed by the clarity and bass is good too. Jim

FullRangeMan · « **Reply #72 on:** 14 Sep 2009, 07:17 am »

Quote from: zygadr on 14 Sep 2009, 07:04 am

I wonder what 2 full size 8 foot X 4 Foot panels of Gatorfoam with 12 exciters per side would sound like??? .............................JUST KIDDING!!

Dear Zygadr, How is this GatorFoam thing? Could you describe me this material, it already came black? It is hard? It broken? etc...
Thanks

j gale · « **Reply #73 on:** 14 Sep 2009, 03:24 pm »

I think the use of full size sheets should be explored. They could be positioned parallel to side walls and so visually almost not there. It doesn,t seem to matter if panel face or panel edge faces the listening position. I might get up the courage to try it. My wiring is just single strands of cat 5. I used it because it's rigid and light and so I thought it would not flap around. I put one panel into a temporary frame (frame opening 3/4 " smaller than panel all around) I mounted panel by means of some 3/4""x3/8''neoprene closed cell weather strip.Panel stands off frame 3/8 inch. I stuck 2 pieces 3/4"x3/4"on each side and 2 pieces near each corner.(total 12) I just used the adhesive side of the weather strip on the gatorfoam and the special 3M stuff Zygadr told us about to stick it to the frame. Don't notice a difference between the free panel and the framed one. Zygadr seems that your design is OK. Eventually I want to try a spine to hold the exciters. That will allow whatever wire you want. Jim

j gale · « **Reply #74 on:** 14 Sep 2009, 03:50 pm »

Sorry made a mistake. Total number of weather strip pieces is 8,only 1 near each corner.

FullRangeMan · « **Reply #75 on:** 16 Sep 2009, 07:14 am »

Thanks Zygadr for this detailed info.

Never see any like GatorFoam here, this mat is very good, better than I was think, will be hard to replace it...
Regards,

FullRangeMan · « **Reply #76 on:** 18 Sep 2009, 02:46 am »

GatorFoam mabufacturer Alcan Composites has closed his factory in Brazil in 15Aug2009.
The plant Site looks do not made GatorFoam, only AlucoBond, Alucore, Dibond, Dilite, AlDesign etc...

FullRangeMan · « **Reply #77 on:** 18 Sep 2009, 03:38 am »

As I wisk a big 75cm x 196cm panel I prefer wait a GatorFoam panel.
Next week I will contact the CaborFiber maker in Sao Paulo, just trying a guess.
Regards

FullRangeMan · « **Reply #78 on:** 18 Sep 2009, 03:55 am »

Great info!! So I will ask for a very thin board, like 1 or 2mm. Lets see how much it will weight!!
Do you know if 8 Dayton exciters are are sufficient for a plate of GatorFoam of 75cm x 196cm to drive in hi SPL in on way mode??

If you work in inches this size is 29,5'' x 77''

scorpion · « **Reply #79 on:** 18 Sep 2009, 09:20 pm »

Hi zygadr,

Sorry to be a bit OT here, I have tried to contact you by PMs, but did you ever get them ?

/Erling