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

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sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3200 on: 31 May 2020, 09:06 am »
Entrepreneur.
Both the exciter and panel material you have chosen have problems with HF ,over on DIY audio ,a study of dml ,some report a roll off as low as 3k!!! And use EQ to "fix" the problem?
The exciter should be properly glued to the panel ,you could also thin the panel in front of the exciter area to allow more sound to emit from the central area.
XPS heavily damps the sound, EPS ,even at 1inch,in my opinion is far better if used properly.
Hope this is of some help.
Steve

57buick

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3201 on: 8 Aug 2020, 08:52 pm »
Hi guys new on the forum but am really interested in playing with DML's just bought some daytons and started playing around recently

57buick

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3202 on: 8 Aug 2020, 08:57 pm »
My first test with XPS panels but then I discovered painting canvas and I am amazed how full these sound. Ill post some pics soon as I am tweaking and testing them a bit this week to see what I need to do but first test on the canvas was amazing full spectrum, just a few spikes.

sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3203 on: 11 Sep 2020, 09:41 am »
This is the is the patent that is very similar to the easy to make diy  canvas picture frame dml panel mentioned over on diy audio.

 https://patents.google.com/patent/WO2019061685A1/en?oq=CN201118973Y

It is as it says ,pretty much a full range panel and would have been interesting to hear how it sounded.
Shame it never made it into full production(that I know of anyway)?
Steve

kb117

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3204 on: 14 Oct 2020, 09:06 pm »
My first test with XPS panels but then I discovered painting canvas and I am amazed how full these sound. Ill post some pics soon as I am tweaking and testing them a bit this week to see what I need to do but first test on the canvas was amazing full spectrum, just a few spikes.

Looking forward to your build!

care to share the dimension of the canvas and the brand/model of exciter you are using?

tia

nickk

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3205 on: 17 Nov 2020, 03:57 pm »
Life is short (shorter for some of us).  So reading through 161 pages looking for the tidbits begs the question ... is there a webpage that provides the pertinent details to build a very nice sounding panel?

I've seen Tech Ingredients YouTube videos and have read other pages but I'm still looking for a more definitive project.  I've Googled and have so many tabs open I need a wider monitor but I'm not finding what I'm looking for.  Basically I'm looking for success first and then I'll delve into experimenting ... and experimenting seems to be the focus of many tabs.

sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3206 on: 27 Nov 2020, 10:25 am »
nickk.
I'm not sure what sort of panel you are looking for,but the above patent and clone painters picture frame are a good start for a full range panel 40hz to 20k.
My personal favourite is still EPS although I have not been testing large panels as I did further back on this thread,I've mainly been concentrating on smaller panels.
But I will be getting back to my old favourites soon!

Over on diy audio A study of DML as full range ,I have posted recordings of various panel materials(I can't see any way of posting recordings on this site) so you can have a listen and choose between them.





Steve

sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3207 on: 27 Nov 2020, 12:34 pm »



 
My latest option of the picture frame ,a 12inch embroidery hoop,using 1mm card,testing at the moment .
Steve
« Last Edit: 27 Nov 2020, 03:06 pm by sedge »

sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3208 on: 28 Nov 2020, 01:04 pm »
Correction.
The card for this panel is only 0.5mm  not 1 mm ,I usually glue two sheets of 0.5mm to make my panels.

I played some Chinese ? Not sure? Type of drum and percussion group,and used the peek hold function to show the response covered over the whole track from about 10ft into the room,the microphone was about a foot of so lower then the panel.
The large drums as you can see are played strongly down to 40hz at which the response drops fast,there a lots of crashes and banging on this track,so this is not a frequency response plot.
Personally I would not use any of my panels down as low as this ,preferring to use a sub for that,but would think using as a near field monitor or for acoustic music should be ok.





I intend to coat the thin cotton with a 50x50 mix of pva to see what happens,if anything.
There are lots of different ways to mount and improve this type of panel so I think it's a good project to start with,it can also be very cheap and easy to produce,you could use a rectangular embroidery frame of picture frame?
Basically it's down to your imagination.
Steve.


sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3209 on: 28 Nov 2020, 01:09 pm »
And I should have mentioned that the response graph is a 30db window ,as it is a petty poor picture,sorry.
Steve

Bendingwave

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3210 on: 4 Dec 2020, 10:42 am »
Life is short (shorter for some of us).  So reading through 161 pages looking for the tidbits begs the question ... is there a webpage that provides the pertinent details to build a very nice sounding panel?

I've seen Tech Ingredients YouTube videos and have read other pages but I'm still looking for a more definitive project.  I've Googled and have so many tabs open I need a wider monitor but I'm not finding what I'm looking for.  Basically I'm looking for success first and then I'll delve into experimenting ... and experimenting seems to be the focus of many tabs.

In the DIY community majority of those into DML are still in the experimental stages and even those that have been experimenting for a long time still have not found a satisfying good sounding dml panel.

My advice is if you want to know how to build good sounding DML panels you dont look for those who are in the experimental stages, you look for those who already developed panels. These are the big commercial industries like Goebel, Manger audio, Bertagni (BES), Yamaha (elephant ear) NS old school series, Shelly kats Podiums. Certain models of Sony's APM series are highly regarded DML/BMR type speakers. DML/BMR speakers are nothing new as they have been around since the 50's or earlier.

Only cons is DML's bass is very limited since they produce bass by flexing and bending (instead of moving air like conventional cones) the panels so larger panels are need since they flex or bend more but there are many complications also with larger panels. DML's are full range so balancing of bass, mids and highs are needed for a good sounding panel. I found it easier to let the DML panel work from 100hz and up while using a conventional (prefer flat cone) subwoofer. This way you can make your panels smaller and use a sub to fill in the low end.

If you look at Martin Logan electrostats they use convention cone for the low frequencies. Some even say Maggies need help from conventional cones subs as there is only so much those ribbons can bend flex unlike conventional cones that can move great amounts of air with a lot of excursion.





sedge

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3211 on: 6 Dec 2020, 12:44 pm »


 https://patents.google.com/patent/WO2019061685A1/en?oq=CN201118973Y

This patent is a good all rounder ,they state frequencies as low as 20hz but my exciter can only get down to 40hz or so using this method.
I notice that they don't say the panel size,but assuming that it is using a 1inch coil ,the panel would work out to be about 15x10inches?
I didn't believe they are just operating in dml mode, but also in piston mode,the output into the room is very strong in this area.

The most satisfying dml material for me is EPS ,as long as all the self noise problem has been taken care of ,of course.
This has been my favourite for well over 10years now, but card for smaller panels is my second favourite ,at the moment,for small -ish rooms they do well.
I have not done any experiments on eps for many years ,but do intend to get back to them soon, as now I have finished my small panel experiments,at last!
EPS has been  the only material that has done everything that I wanted  from a dml panel and yes I agree that using a LF driver below 100hz is by far the best sounding and performing setup.
Steve.



nickk

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3212 on: 6 Dec 2020, 02:30 pm »
Thanks to all above for the input. 

In the DIY community majority of those into DML are still in the experimental stages and even those that have been experimenting for a long time still have not found a satisfying good sounding dml panel.

I was hoping that somewhere (that I have yet to find) was a distillation of what has been learned via the experimentation. I'm not against experimenting but was hoping to build on the current knowledge base and avoid the wrong terms.  Depending on Santa, I may be starting in January.

Bendingwave

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3213 on: 6 Dec 2020, 09:19 pm »
Thanks to all above for the input. 

I was hoping that somewhere (that I have yet to find) was a distillation of what has been learned via the experimentation. I'm not against experimenting but was hoping to build on the current knowledge base and avoid the wrong terms.  Depending on Santa, I may be starting in January.

Thats not easy to answer as it depends on who you ask as there are many different designs and it will come down to your personal preference.  There are a lot of beginner entry level intro designs out there that dont sound that good but gives one a glimpse into DML's potential when designed right. Some swear that hanging panels is the best method while others like my self claim that panels are best supported by a frame and spine. Some will say XPS or Celing tiles are good materials and some will say EPS is better. Some build these panels just for fun and others like myself take it real seriously and build these panels to compete in the hi fi audiophile market when it comes to sound performance but at only of the fraction of the cost.

Recent popularity of DML's stems from Tech Ingredients youtube vids on DML I will give him that but other then that his design is a beginners design he just basically copied Rich Ms design from P.E. project gallery and added his own twist. When I read the comment section on T.I. vids those praising his design are just average joes that dont have experienced ears of what Hi fi is all about. In his vids he compares is panels with a I think Polk audio speaker? Those speakers sound better then his panels. Even the average entry level speaker like Andrew Jones Pioneer designed speakers at less then 200.00 a pair sound better then T.I. design.

So it all depends on who you ask. You could ask 100 different people and get 100 different answers. So how does one know who to ask and or what to look for? Its simple you look for those who have designed a very good sounding panel.

These high end Gobel speakers use DML bending wave technology>https://www.youtube.com/watch?v=YOy4XmVICRw

Sonnar

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3214 on: 27 Jan 2021, 04:49 am »
Hi all, first post but I've been stalking this thread for a while. I finally got my first test panel cut a few minutes ago. It's a small 250mmX404.5mm 25mm XPS panel, gonna start sanding now and apply the pva/water mixture and then start cutting another design.

Nice panels. Can you please give us more info. How did you cut them? How do. they sound?

Sonnar

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3215 on: 2 Feb 2021, 08:06 am »
I have a pair of exciters ASX05408-HD-R from PUI audio.
https://www.digikey.com/en/product-highlight/p/pui-audio/sound-exciters-speakers
I am uploading their datasheet.
They look like an interesting option for exciters
Thank you.


Geshat00

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3216 on: 19 Feb 2021, 09:45 pm »
I actually have those exact exciters. The problem is they have no screw mounts. I had them mounted on my windshield of my car, but the engine blew before I could ever hear them. The magnets are quite heavy and one ended up falling of the windshield. I have their tactile transducers ASX08604-SW-R and they're great. I have one mounted on my computer chair and have two mounted on an air mattress I use for meditation. I know not the typical use, but meditation is always better when you can feel it!

brunolalb

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3217 on: 10 Jun 2021, 05:36 pm »
Hey guys,
about 3 years ago I assembled my DML speakers with Dayton exciters and very stiff Styropor plates. Together with a Subwoofer they work very well.

Now my problem is that one of the exciters fell down (I guess the adhesive gave up) and I'm looking for an adhesive (tape) to glue them back. Everywhere I look for it says "3M VHB", but there are tons of different 3M VHB tapes. Does anyone know which tape exactly is used?

FullRangeMan

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3218 on: 11 Jun 2021, 03:19 am »
I not a expert but I could prefer adhesive for hi-fi use, tape looks suspect to me YMMV.

Bendingwave

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Re: NXT.......rubbish??....THINK AGAIN!
« Reply #3219 on: 11 Jun 2021, 09:11 pm »
Hey guys,
about 3 years ago I assembled my DML speakers with Dayton exciters and very stiff Styropor plates. Together with a Subwoofer they work very well.

Now my problem is that one of the exciters fell down (I guess the adhesive gave up) and I'm looking for an adhesive (tape) to glue them back. Everywhere I look for it says "3M VHB", but there are tons of different 3M VHB tapes. Does anyone know which tape exactly is used?

Eventually all the tapes will give out especially if there is no spine/brace holding the exciters weight up.  If you want permanent then 5 min. epoxy glue is great.