[mikadosan]

Any accidents with the shellack? Success or a pair of ruined CC sheets...

[captainjack115]

"I leave this with you for comment if you like. I've been factual and honest with all here.
I believe that we have come as far as we can go within the limits of a diy panel.
To me it's a speaker that can be used for some music, but fails on a good chunk of others and is dependent on transient severity and power input to survive."

I agree!

I haven't posted for a while because I had nothing to contribute. In my opinion, one exciter per channel and some cardboard works very nicely for an up grade in sound for a computer.

I been playing with line sources with amazing results. Full range with bass to 20 Hertz, no crossovers.

[j gale]

 Zygadr,  Where to from here :dunno:If the panels can't do live orchestra neither can almost anything else. I agree that the cardboard has it's own character but that is altered by coatings etc. Lots to be learned there. Jeffac seemed to do OK with his tung oil. I guess that what ever is used has to be thin enough to soak in thoroughly and immediatly. If my experience and what I know of yours is any indication you will be back playing with the panels soon because they make music. Even with the frustration improvement has been steady. Some of what they already do can't be matched. Ziggy have a rest. See you soon

[bobloblob]

I know what I am about to suggest has not been the goal of most on this thread, but as I said early on, if this only makes a great wide-range speaker, not a full-range one, that would still make me happy.  It looks like this might still work well that way.  Why not try combining it with something like Martin King's H-frame dipole sub?  It uses an inexpensive Goldwood 18 inch woofer, and all reports are that it is excellent.  The panels could either be placed on top, or to the sides.  I think it would be a shame to have come this far and dump the project because it won't go full-range without problems that it may not have if limited to say 150 Hz and up, especially since it seems to deliver so well on the sound.

As for shellac and tung oil, they work differently.  Shellac is primarily a surface coating.  I don't know how far into the paper the shellac itself penetrates, although the alcohol will soak through everything.  Many oils and varnishes will penetrate more deeply, and then harden by polymerization, caused by a catalytic reaction with oxygen, as least that's what my addled memory tells me.  Some products - Watco, Deftoil, Minwax antique oil finish, for instance, are meant to penetrate deeply and then harden, as does Wood Hardener, which will penetrate even deeper and set up harder too.  They will also most likely increase the weight of the panel some.  Which one works better I don't know, but they are somewhat different in how they do what they do.  Shellac is a spirit finish - it hardens by evaporation of the solvent, alcohol, and it is somewhat reversible. The other finishes above have a state change, from liquid to solid, and that is irreversible - mostly.  Hope I am not boring you with this, but I thought some may find this info useful.

If you can accept some limits and compromises, you might still be on the track of a fine system.

Take care all.

[mikadosan]

I haven´t posted anything yet about my own experiments for a good reason. I have been walking quite similar path than Zygadr but I have to admit that I´m not even close to give up the experiments then... For me personally, my panels can offer some very serious sound quality that will beat up every single fullrange box I have...and I have many, I can tell you that...with the cheapo drivers and some very very expensive ones...

I have made some experiments with the panel materials and have bought a large number of different kind of materials including all the different types of foam boards, fluted plastic sheets, different kinds of cardboards, Nomex honeycombs with different skins, etc...

My latest "invention" is a little bit different. I made my own composite by using the 0,5mm aluminium sheets and 2mm cork. The panel itself is a bit on the heavy side if compared to the other materials but its sonical and tonal qualities are nothing but very interesting. Cork has a very good internal damping factor and aluminium skins will stiffen the panel very well when glued properly. It is very important to get a good and even press during the gluing process so that you can get a straight panel. But when you have a success, you have a quite nice panel material indeed...

My panels are not the biggest ones on the block but they really do play music very very nicely. If compared to anything I have tried so far, this is indeed a winner. The weight is an issue of course and will affect the sensitivity of the finished panel speakers but for me personally the tonal qualities are more important than sensitivity.

Next project is to make a new different kind of composite with a skins made of plastic. Either PP, acrylic or polycarbonate. It is of course important to find a very thin sheet of plastic so that we will not add any extra weight to the panel then...

I´m using two different kind of exciters on my prototypes. The other pair is using the 32mm balanced exciters (4 exciters per panel) and the other protos are using the new 25mm SFH exciters (quite strong ones!!). Balanced exciters seems to be able to offer a very neutral and natural sound with this panel type. SFH exciters are almost as good as well but will offer a little bit more sensitivity and bass extension.

I will continue my search for the best combination but obviously it seems that I´m quite close to that anyway...

In the mean time, I will listen some nice jazz with my panels with a wide smile on my face...

Best regards

-Mikadosan

[Tinnitus]

I´m using two different kind of exciters on my prototypes. The other pair is using the 32mm balanced exciters (4 exciters per panel) and the other protos are using the new 25mm SFH exciters (quite strong ones!!). Balanced exciters seems to be able to offer a very neutral and natural sound with this panel type. SFH exciters are almost as good as well but will offer a little bit more sensitivity and bass extension.

-Mikadosan

Hi Mikadosan,
Could you tell us a little more about your exciters and where we might be able to purchase some (What does SFH stand for?, what did you pay?).
I have been having trouble sourcing affordable exciters of any make here in the UK, ironic really as NXT are based near Huntingdon.
Parts Express offer units at $5 a pair (!) but they require a minimum purchase of $50 which would then cost another $50 to post to the UK, that's too much for cheap (and nasty?) transducers, and I only need about 8 to get me started.
I have recently contacted NXT re' samples and prices but I'm still awaiting a reply.
I'm really keen to try some ideas I've been 'working on', and of course some of the approaches which everyone on this forum have developed, but I can't do it without trandsucers!.

bobloblob's info re' Tung vs Shellac was very interesting, will have to investigate further.

[sedge]

tinnitus
sfx technologies -£56 per pair plus p+p
zygadr
in a nomal size room in England[shoe box]one exciter on a large panel gives plenty of volume.
imho I think that one panel ,no matter how many exciters you use ,will output only so much before cone breakup .
peaple stack quads for this reason ,but they might also say it muddies the sound ? could this be the way for large output of nxt ?

[mikadosan]

Hi,

Parts-Express is a good source for the exciters. You can find out that they sell three or four different types of exciters under the Dayton brand. Basically these are of course the NXT licensed products made by Billionsound (in China). Biggest problem in the pricing of the exciters is the NXT license fee that has been "baked" in the price of each exciter.

Maybe you could arrange a group buy with mates to get the shipping fees splitted?

I can post some pics of my experiments. At the moment I have only an IPhone as a camera so you can forget the superb quality photos then...

It would be a wise move to check the NXT patent papers if you want to avoid the basic mistakes with the DML technology. They are free to use for the hobbyists as they are all public documents. But beware, there´s approx +1000 different documents under the New Transducers Limited...plenty of documents to read then...

About the pricing of the exciters...there´s no free meal if we are talking about the quality of exciters. Best ones are a bit on the pricey side but I think that they are worth it. Thats my opinion.

I forgot one panel material from my list of experiments. I once tried the heat tensioned Mylar (or something similar) in a birch plywood chassis and it seems to be quite interesting one too. The basic invention is made by Mr. Paul Burton, he knows thing or two (a lot actually!!) about the DML technology as he´s one of the brains behind all this then...

Tensioned film panel is not the easiest one to get it right but when you have a success, it is indeed an interesting test. There´s also two commercial loudspeaker models using this technology - Sumo Aria and Melior "something" (I forgot the name of the manufacturer, sorry!!). I´ve heard that these two sounded actually quite nice but were horrible ones to manufacture. And panels also breaks quite easily if they get punctured, etc...

I found out that this method is not very easy if you want to make two identical panels. But with plenty of work, blood, sweat and tears and voilá... They really do sound quite nice with only one exciter attached to the panel. Tension is supposed to be like a drum skin so you will need some experiments before you get a success then.

I try to take some photos of my protos as soon as possible. In the meanwhile, I recommend that you should take a small economical "risk" and invest in some good quality exciters and start the experimenting...it sure is FUN...

-mikadosan

[jonners]

I for one would be interested if there were a group buy in the UK of the cheap Parts Express exciters.

[Tinnitus]

Wow, thanks for all the info Sedge and Mikadosan.
SFX are about 2 miles from me!!!!!
I'm really keen to try a pair of their units but I think I'll try some cheapo's first if I get enough interest to get a group buy together, how many would you be looking for jonners?.
$100 will get us 20 exciters(thats the minimum order).
At current exchange rates that's about £64, if we split them 2 ways that's affordable for me.
Would you be willing to buy 10 off me (around £32 plus p+p from me to you) if I order 20 for us?
If 10 is too many for you maybe we can find someone else who's interested?
£3.20 per exciter is pretty cheap, anyone else in the UK interested?.

I fancy trying inflated structures and maybe stretched silk so the stuff about mylar film was encouraging.
I have an Idea about replacing my soldering iron tip with a needle and using it to melt tiny holes around the foot of the exciter so that I can sew it tight to the fabric.
This would also allow the use of another exciter on the other side of the panel/sheet, but wired out of phase so that the two units re-enforce rather than cancel each other out.
Does anyone who owns the cheap parts express exciters think there's enough room around the foot of the unit to allow the melting of holes?

[bobloblob]

Museatex developed a line source and a point source using mylar, so it can be done, and apparently can be done very well.  Read through the page linked to below, particularly the posts by morayjames, a very bright and helpful (and unassuming) guy, who was a major (perhaps the major) developer of that speaker.

http://www.diyaudio.com/forums/multi-way/100392-beyond-ariel-47.html

This would no longer be a DML speaker, as the panels are, at least through part of their range, and its benefits would be quite different.

[mikadosan]

Ah, yes... Museatex was the name that I lost...

I have read all the info that Moray has written about the project. And that is why I just wanted to test it. It was a surprise that after a few try I managed to get the film speakers sing quite nicely.

I have tried the following exciters already:

- Dayton DAEX25
- Visaton EX60 8Ohm
- Feonic F4 drivers (magnetostrictive exciters)
- Dayton 32mm balanced exciter
- Dayton 25mm SFX exciters
- few piezo elements
- ....etc, etc...

And I can tell you that none has been as good as the Dayton (NXT) 32mm balanced exciters and 25mm SFX exciters.

Visaton EX60 exciters tend to sound a bit shouty even if you´re using some more damped materials then. They have quite nice sensitivity, etc though... But they tend to sound a bit too hard and shouty. These are not actually based on the NXT technology but some old Japanese manfacturers technology which is quite similar one...

Feonic drivers are way too limited on their sensitivity figures and their behaviour on any "normal" panel materials are a bit odd. Feonic has released a technology named "Whispering Windows" and yes, whisper they can but nothing more than that then... But this is of course only my opinion and is based on my experiments with the Feonic F4 drivers.

The exciter that Zygadr posted has not gained very good reputation amongst the clients. And they are ridiculously expensive if compared to the Dayton series of exciters then... Hard to imagine that one would like to invest that much on one exciter then...

Best regards

-mikadosan

[jonners]

Wow, thanks for all the info Sedge and Mikadosan.
SFX are about 2 miles from me!!!!!
I'm really keen to try a pair of their units but I think I'll try some cheapo's first if I get enough interest to get a group buy together, how many would you be looking for jonners?.
$100 will get us 20 exciters(thats the minimum order).
At current exchange rates that's about £64, if we split them 2 ways that's affordable for me.
Would you be willing to buy 10 off me (around £32 plus p+p from me to you) if I order 20 for us?
If 10 is too many for you maybe we can find someone else who's interested?
£3.20 per exciter is pretty cheap, anyone else in the UK interested?.

Hi Tinnitus

I've sent you a PM

[Tinnitus]

Ok jonners, thanks for that reply, we'll give it a day to see if there's any other uk interest.
I imagine that these cheap units will be pretty crappy but it seems a sensible place to start experiments?.

I have tried the following exciters already:

- Dayton 32mm balanced exciter
- Dayton 25mm SFX exciters

And I can tell you that none has been as good as the Dayton (NXT) 32mm balanced exciters and 25mm SFX exciters.

I'm a little confused, do you mean these?:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-378
and
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-377
.........................?...................
Thanks for sharing your experience of all these exciters with us, it's especially useful for beginners like me who've yet to buy what's needed.
Sadly parts express has neither of the units above in stock.
I'm tempted by the units made by SFX (and they're on my doorstep!):

http://www.sfxtechnologies.co.uk/epages/pzkqx2jfdkxv.sf/en_GB/?ObjectPath=/Shops/sfxtechnologies.co.uk/Categories/%22Gel%20Audio%22

but they're a bit pricey to experiment with.
Although the cheaper ones might be better than the cheap ones available from parts express?:

http://www.sfxtechnologies.co.uk/epages/pzkqx2jfdkxv.sf/en_GB/?ObjectPath=/Shops/sfxtechnologies.co.uk/Products/%22SFX%20GA%2010%22

Do any of you guys with experience of trying different exciters have an opinion on the SFX manufactured units?, or indeed any direct experience of them?.
zygadr, you 'crabs' post made me LOL.
I'd seen the other video before, but really, they're using bin-bags and the way they 'tensioned' the material i'm amazed they got any sound at all from that!.
With all due respect to them they probably didn't really expect much bass either from a cheap and dirty experiment like that, kudos to them for trying it, filming it, and posting it on the tube though!.
I think my first experiment will be stretched silk (tight!) with exciters sewn on, and maybe some sort of resin or hardener brushed on to the silk (after stretching) to stiffen it.
Inflated structures will take a lot longer to try but I'm still keen to try.

Does anyone know of any other good sources for exciters that'll ship to the UK?

[sedge]

tinnitus
the exciters from parts express might be cheep ,but they are not crappy infact they are very good.
I have used them on very thin ali ply,card ,cc,foamcore, wood ply and others,one of the main problem seems to be efficiency,so far thin single layer cc is about the best for high output level [I have just got hold of some shellack to see if this can be improved on ]some of the less efficient are very good sounding .oooops must go dinner is on the table

[mikadosan]

A sleepin giant?  Yep, that´s me then...    (joke)

Basically it is not a problem for me to buy few of these Revolution Acoustics exciters. If you like, I can order few pairs and have a good test session with them.

Let´s see if I can make some kind of agreement with the Revolution Acoustics themselves. Stay tuned!

About my postings of my experiments...as I said, there is a GOOD reason that I have remained silence. But fear not, until I get some reasonable results (I mean...seriously) I will update my zero project description in here too...

-mikadosan

[Tinnitus]

Let's stop going around in circles which I believe is starting to happen............I'm not blaming anyone in particular, just keep it real guys.

WTF? We can't all afford to 'keep it real' at 500 bucks a pair.
Good luck to those who can, I'll be fascinated to learn mikadosan's conclusions should he choose to post them.
Does anyone else have any direct experience of the SFX units?

I'd like to ask again if anyone has tried putting two exciters facing each other on either face of a panel, with one unit wired to 'pull' while the other 'pushes'?
This might be the same as just mounting two units in separate locations but I suspect that there might be less chaotic interference if they were in synchrony.
Of course maybe DML thrives on interference.

[Tinnitus]

tinnitus
the exciters from parts express might be cheep ,but they are not crappy infact they are very good.

Thanks sedge that's good to know, I'm definitely going to try them in that case.
jonners and I are going to go halves on an order, I think I'll order them this eve'.
If anyone else in the UK wants to participate in this order just let me know, but you'll have to be quick, as I'm impatient to order these 'cos they'll take ages to ship!.

[usp1]

WTF? We can't all afford to 'keep it real' at 500 bucks a pair.
Good luck to those who can, I'll be fascinated to learn mikadosan's conclusions should he choose to post them.
Does anyone else have any direct experience of the SFX units?

I'd like to ask again if anyone has tried putting two exciters facing each other on either face of a panel, with one unit wired to 'pull' while the other 'pushes'?
This might be the same as just mounting two units in separate locations but I suspect that there might be less chaotic interference if they were in synchrony.
Of course maybe DML thrives on interference.

I tried putting the cheap $5 exciters one on either side (both in and out of phase) on a cardboard panel and in both cases the results were terrible. It seems there is a lot of cancellation when one does that.

[mightym]

I think my first experiment will be stretched silk (tight!) with exciters sewn on, and maybe some sort of resin or hardener brushed on to the silk (after stretching) to stiffen it.

Interesting idea, if the Sumo, Aria's were using a mylar type of material then the silk ought to work too.  My own tendency would be to dope the fabric somehow too. (OT) I wonder what the compound is that is used to treat tweeter domes.

I'm not sure I would try to sew them on....
once stretched and doped I would think that glue would be the preferred choice.  trying to stitch through the spider of the exciter would probably result in a torn spider.  there are tremendous amounts of small transient forces at work there.

I could be all wet too.  So if you try it pls report.

I wonder of these exciters could be shipped in a padded envelope, as a personal letter, and whether it would speed the transit?  I might be willing to assist, contact me with a PM

John