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

zygadr · « **Reply #1720 on:** 11 Apr 2013, 03:59 am »

More information received today from Hi Wave.
BL/HIGH SHOVE is as expected.............more efficiency and overall sensitivity.
So...........the ideal exciter for a thin plywood panel is one with the highest BL rating.............simple.

I have questioned HiWave's recent exciter recommendation as it's BL is not the highest in their range of exciters available????

On another note...............where the hell are you guys!!!!.............I'm here freaking killing myself to get some useful information to drive the ultiimate panel material and you lot are hiding in the dark!!!!??

tino84 · « **Reply #1721 on:** 11 Apr 2013, 07:48 am »

hi zygadr.
I yet tried plywood in my tests, having good result.

As I said some time ago, the only limit about NXT is sensibility.

However, your job is very interesting, I always check this thread to see your progress.

PS: I would try to use NXT in combination with OB fullrange.. any tips?

PPS: have you tried Cambridge BMR technology? ( as Cambridge audio Minx )?

zygadr · « **Reply #1722 on:** 11 Apr 2013, 11:36 pm »

Hi tino84.
Sensitivity can be made to be quite high if you use the highest power exciters (high shove) and lots of them on a large panel.

Using exciters on an O.B. with regular drivers is not where I wish to go. My idea has allways been a full range panel using exciters only.

Hiwave have NOT responded to my last question..............I would say that because I am not a company intending on buying hundreds of exciters from them that they will no longer communicate with me.
From here on it's up to me to try a high power exciter and see what happens.

4krow · « **Reply #1723 on:** 12 Apr 2013, 01:34 am »

New guy here. Gotta say that the first time that I heard this technology, my brain just wouldn't accept it. The sound was better than it should have been, and of course, what the device sat on made a big difference in sound. I haven't had time yet to experiment, but by chance I do have a T amp on the way, so that is a beginning. Will read this thread to get ideas about what transducer would fit my application.

tino84 · « **Reply #1724 on:** 12 Apr 2013, 08:49 am »

Quote from: zygadr on 11 Apr 2013, 11:36 pm

Hi tino84.
Sensitivity can be made to be quite high if you use the highest power exciters (high shove) and lots of them on a large panel.

so, I will search for it here in EU..

Quote from: zygadr on 11 Apr 2013, 11:36 pm

Hiwave have NOT responded to my last question..............I would say that because I am not a company intending on buying hundreds of exciters from them that they will no longer communicate with me.

I hope they will answer you, otherwise this would be a stupid behaviour..

bjohng · « **Reply #1725 on:** 12 Apr 2013, 02:19 pm »

Hi Zygadr

Just to let you know that you are not alone!

Over the last 2 years I have tried the original devices using various types and thicknesses of foam panels/boards. Each had a distinct tonal quality but at the end of the day none were satisfactory.

In my journey so far I have discovered that:

1. Thin plywood yields an overall sound far superior to any of the foams.
2. Multiple exciters are necessary.
3. You need large panels - less than 2' * 4' are a waste of time.

I still have a feeling that an irregular shape may prove beneficial - maybe a truncated pyramid? This is an area that the electrostatic panel developers have toyed with.

The limiting factor to date may be that the original exciters just need to be driven too hard. If your current plans to use the higher shove units confirm this then I think we can dip our toes in the water again with renewed confidence. In the meantime I continue to use a larger panel for the center channel of my home theater set up - behind an acoustically transparent screen. Speech articulation is better than any boxes I have used.

On the subject of Hi-Wave you may not buy 100's but collectively we will be

Look forward to your reports with continued interest.

zygadr · « **Reply #1726 on:** 14 Apr 2013, 11:43 pm »

Great news!.................Hi Wave have replied and I quote :

''The exciter I suggest is more ideal as it has the performance , but also, more importantly,it is suited for adhesion to a wooden surface.
The HIAX32C20-8 exciter you were considering is designed to drive 1/4 inch glass panels and will adhere to glass or plastic smooth panels, but would not adhere and stay in place on a wooden panel.
Hence the suggestion to use the much more suitable HIAX32C30-4/B available from parts express.''

So there you have it guys............straight from the horse's mouth. These exciters that HiWave has recommended are rated at 30W, and four per panel should give plenty of power handling and output on thin plywood panels.

I don't know if they are back in stock yet?..........will have to email P.E. to find out.

zygadr · « **Reply #1727 on:** 15 Apr 2013, 12:18 am »

O.K..................There is a ''NEW KID ON THE BLOCK''..................this time from Dayton, not Hiwave. It's just as powerful, cheaper and can be mounted on to virtually any surface (INCLUDING WOOD!!!).

I believe this would be a better exciter to experiment with in regards to driving plywood panels :

http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-210.

It looks similar to the Visaton units but cheaper AND it's IN STOCK

mkstat · « **Reply #1728 on:** 18 Apr 2013, 04:32 pm »

Hi all!

A very interesting exicter. Maybe it´s from the same OEM manufacturer as the one Visaton sells. I have the feeling that it should not be used without some kind of support of the magnet system thoug.

This is a picture of the EX 60 taken from the Visaton page:

About two years ago i used a very small airply panel (137mm x 100mm x 0.8mm) for a closed back tweeter panel in a 2-way rear speaker used in a home theatre system. It had a very flat frequency response, usable from 1khz up to 20khz and an exeptionally wide dispersion.
I laminated two sheets of 0.4mm thick, 3-layer airply in a 45° angle, the direction of the top layer fibres heading to the corners. A major improvement compared to a single 6-layer 0.8mm airply with normal fibre orientation. This might not be an option for large panels but i think the fibre orientation plays a big role in anisotropic panel materials.
By the way, i had no problems bonding the exiter with double sided 3m tape to plywood. I just sanded the panel up to 320 grain and applied a thin layer of nitrocellulose varnish. After two years of operation the exciters are still in place.

regards
-m

zygadr · « **Reply #1729 on:** 18 Apr 2013, 11:39 pm »

Hi mkstat.
Ordered 8 of the dayton exciters from Parts Express last night.
Yes, they are the same unit as the Visaton - 25W rms, 40W max. They will most likely need a rear spine support from the appearance of voice coil droop in the picture you posted.

So far, the 2.7mm high quality plywood has been an absolute revelation

The transparecy and clarity is truly amazing. I personally have no desire to try any other material. With the ply, you can listen to music all day.........instruments take on a very realistic tone that is hard to match with all other materials tried so far.

With the new exciters, amplifier volume can be increased without worrying about overheating or blowing them as has been the case with the cheap 5 W ones I have used in the past.

This is going to be interesting!

j gale · « **Reply #1730 on:** 19 Apr 2013, 03:14 pm »

Hi Zygadr, Are you able to give more info about your 2.7mm plywood? What is the wood? Are the layers of equal thickness etc. The baltic birch I tried wasn't as good as my shellac treated cardboard. I think still too heavy. and that is with the 32mm self supported exciters HIAX32C20-8. force factor7.8. I'm finding them very good on my cardboard. Just a warning though, these are very difficult to re-use. The outer tape ring (the self supporting arrangement) is attached to about a 3mm thick foam ring. I guess to allow independent movement of the exciter foot. all that extra force factor didn't make a huge difference--still not enough volume from the ply to make it a keeper. The dayton/visaton exciters look like a better arrangement even if you need a spine which is very easy to do in my experience. Looking forward to your assesment of your new exciters. PS I did re-use the HIAX32C20-8 with difficulty but I don't believe I could get away with it twice. Jim

zygadr · « **Reply #1731 on:** 22 Apr 2013, 12:26 am »

Hi j gale.
When HiWave advised against using the HIAX32C20-8 for wood, I decided to go for the Dayton exciters. Another reason was that the new Daytons are the highest power rating in the ''high fidelity'' range of transducers which is important if we are to go the thin wood route.

The 2.7mm ply was purchased from Bunnings here in West Australlia. There is a small green label on the 4 X 3 sheet that states ''premium plywood BC grade.
I don't think there is any other information(but I will check)on it. It is definately NOT marine ply, and I doubt that it is Birch.

The 4mm marine ply sheet I tried had much less output than the 2.7mm premium ply.........very obvious. The marine ply was dead and dull sounding...........useless.

I will ring Bunnings and try to find out what type of wood this 2.7mm ply is made up of.

zygadr · « **Reply #1732 on:** 22 Apr 2013, 07:39 am »

Wife just rang :

THE DAYTON EXCITERS HAVE ARRIVED!!!!!!

jackman · « **Reply #1733 on:** 22 Apr 2013, 01:29 pm »

This is the longest thread on this site. Has anyone ever made a functional speaker with good skid from these exiters? Are they able to play at normal listening levels?

j gale · « **Reply #1734 on:** 22 Apr 2013, 04:27 pm »

Hi jackman, There is a good reason for this thread being as long as it is. Yes these panels can play at normal levels. My own cardboard shellac treated panels will play much louder than I can stand. Volume only seems to be an issue with materials that are too heavy. Once the clarity, coherence, musicality of these has been experienced you can't give them up. My horns, open baffles, MLTLs etc can't compete. One reason for the length of the thread is the fact that for the most part trial and error is how everything has been learned. Assumptions based on knowledge related to "normal speakers"are generally useless. These don't conform to the rules. Usually comments by the technical guys are so far off what we experience and hear. I can happily live with my panels as the are, but I can't stop looking for the better panel material or the better exciter, especially since the whole experience has led to better and better results. For me, the whole effort has been great fun. I hope this thread keeps growing. Jim

zygadr · « **Reply #1735 on:** 24 Apr 2013, 07:28 am »

Well said Jim

............your post sums up exactly what this technology is about.
I thought that that my giant horn system would be with me forever and I can clearly remember stating that fact to many audiophiles...............UNTIL......????

Having had Magneplanar Timpanis, Electrostatics, horns and standard forward firing box speakers, the NXT panel is a strange and spectatcular creature that hooks you quickly and hooks you hard. Their sound is unique, and that is an UNDERSTATEMENT!

I am yet to mount the new Dayton exciters, but can already report that construction and appearance wise, these are in a different class from what we have been using in the past.
The first thing noticed is the size of the exciter body (less mounting plate).......it's bigger by about 25%.........same goes for the weight. The contact/terminals are far better executed and the whole unit looks like serious hardware.

Hope to have something up and running by this weekend and will post some pics.

Rob.

mkstat · « **Reply #1736 on:** 24 Apr 2013, 10:47 am »

Maybe this is an interesting information regarding exciter spacing in dependency of panel properties:

http://www.freepatentsonline.com/7564984.pdf

It´s also interesting that one of the inventors obviously designed the first prototype of the Podium speaker

http://www.diyaudio.com/forums/planars-exotics/100256-podium-sound-planars.html

regards
m

zygadr · « **Reply #1737 on:** 26 Apr 2013, 04:34 am »

Thanks m!!
I'll read the patent tonight. Looks like some exciter placement experimenting will be in progress soon!

hblester3 · « **Reply #1738 on:** 4 May 2013, 09:26 pm »

Ziggy how is the new exciters working? Waiting for the news hope there are not any problems. I had major car problems which has slowed my progress. Also interested in if you have experimented with placement of the exciters. You said you ordered eight exciters i guess you are going to use four per panel and what size panel.

Hubert

zygadr · « **Reply #1739 on:** 6 May 2013, 01:38 am »

Hi Hubert.
Sorry......have been a bit busy with other issues and have not yet tried the exciters. Maybe tonight.

In the mean time......some interesting news! A local electronics hobby shop has these in stock ! :

They are 70mm in diameter, 1.25 inch voice coil, 8 ohms and 15W rms power (That may be conservative) and weigh 125g. The specs, apart from the power rating, closely approach that of the new high power Daytons and Visaton units.
In Australia they cost $15 - which is cheaper than ordering from parts express.

With these, I may use 8 per panel(including the Daytons). The panel will be 6 feet X 3 feet.