Just curious and asking what others think about it. I cannot really tell from the specs provided if it is likely to be an improvement over regular EPS, but seems like it could be worth a shot.
It is priced between EPS and XPS, and while it is not available in single sheets, a package of 6 1200x600x50mm is €50.
And it sure looks a lot better without painting IMO.
Found a place in Germany which ships 500x330 plates of Neopor in either 10mm or 25mm thickness: https://www.dekokopf.com/styroporplatten/
Ordered some to try out.
EDIT: Also have a selection of what seems to be quite high grade regular EPS plates (25 kg/m³) in good size and thickness. Will try to add some of those to the order to compare as well.
Ordered some to try out.
EDIT: Also have a selection of what seems to be quite high grade regular EPS plates (25 kg/m³) in good size and thickness. Will try to add some of those to the order to compare as well.
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So happy I found a sensible source for EPS...was about to order two €50 packages with a bunch of 1200x600mm plates (EPS S80 and Neopor), but very glad that I haven't. Wife is very understanding about me spending time and money on crazy ideas, but when they also mean a lot of bulk to take up storage space, even she can get fed up :\
But now for less money I get enough plates to experiment with of three different qualities delivered to my door and in a size that I can stash away!
Now the question is what to try to cover them with. I will try PVA as a reference, but should handle moisture badly, so for outdoor use it seems less than ideal.
Is jury still out on epoxy on EPS? Tempted to look in to shellac as well.
But now for less money I get enough plates to experiment with of three different qualities delivered to my door and in a size that I can stash away!
Now the question is what to try to cover them with. I will try PVA as a reference, but should handle moisture badly, so for outdoor use it seems less than ideal.
Is jury still out on epoxy on EPS? Tempted to look in to shellac as well.
Leob.
You mentioned 50mm eps, which is far too thick for home audio use,in my opinion ?
but DML speakers.com use them for pro use with eq.
I have not as yet used epoxy on a full eps panel,so I can't comment.
but the epoxy and fibreglass,if used ,will swamp the eps sound,as it does with the xps .
No need to sand the panel before hand ,unless you want the epoxy to soak into the eps a little more ?
I glued on the exciters to my test eps panels yesterday, so hopefully I will have a listen today before coating the whole of the panels in pva.
I like to listen at every stage to make sure of what I am doing ,and why?
I'm not sure how well epoxy would go on top of pva, for the final experiment ?
Steve.
You mentioned 50mm eps, which is far too thick for home audio use,in my opinion ?
but DML speakers.com use them for pro use with eq.
I have not as yet used epoxy on a full eps panel,so I can't comment.
but the epoxy and fibreglass,if used ,will swamp the eps sound,as it does with the xps .
No need to sand the panel before hand ,unless you want the epoxy to soak into the eps a little more ?
I glued on the exciters to my test eps panels yesterday, so hopefully I will have a listen today before coating the whole of the panels in pva.
I like to listen at every stage to make sure of what I am doing ,and why?
I'm not sure how well epoxy would go on top of pva, for the final experiment ?
Steve.
Yes, with 50mm I was planning of having to cut them.
But now I have instead ordered an assortment with 10 and 25mm 25kg/m3 GPS (Neopor), 15mm 25kg/m3 EPS (Peripor) and 25mm 20kg/m3 EPS (Styropor)
I'm leaning more towards the shellac actually. With a shellac with low wax content and applied correctly it should handle moisture. Like with all natural materials with no drying agents you have to handle them correctly though. It will dry quickly in thin layers, but similar to linseed oil paint, paint it too thick and it will never dry. And using drying agents will make it too dry with time and result in cracking. But seems relatively easy to use. People just don't have time to wait 40 minutes between layers nowadays, which is why synthetic lac have become more popular.
Maybe I should point out that the surface on the lower grade eps is softer than the higher grades.
Is this down to the cutting methods ?
I noticed that moulded eps also has a softer surface .
So if the panel has a soft surface already, there is no need to sand off the hard surface .
I've also noticed that different panel materials react differently will the sound within the coil area.
The more reflective materials seem to make the exciter more noisy , a little bit like the noise in a council swimming pool surrounded by tiles on the walls.
it is at least one of the reasons the exciter is noisy anyway.
I have not coated the inside of the coil foot , to see if I can hear a difference in the noise from the back of the exciter, will it reduce the reflections within the coil cavity.?
We shall see ?
Steve.
I have as yet to hear a better sounding surface on eps than thinned pva, and also my other panels, come to think of it.
but I am always on the lookout for something better.
Is this down to the cutting methods ?
I noticed that moulded eps also has a softer surface .
So if the panel has a soft surface already, there is no need to sand off the hard surface .
I've also noticed that different panel materials react differently will the sound within the coil area.
The more reflective materials seem to make the exciter more noisy , a little bit like the noise in a council swimming pool surrounded by tiles on the walls.
it is at least one of the reasons the exciter is noisy anyway.
I have not coated the inside of the coil foot , to see if I can hear a difference in the noise from the back of the exciter, will it reduce the reflections within the coil cavity.?
We shall see ?
Steve.
I have as yet to hear a better sounding surface on eps than thinned pva, and also my other panels, come to think of it.
but I am always on the lookout for something better.
As I understand with EPS you expand the styrene granules in a mould by steaming them. The individual expanded bubbles in the EPS have a little bit of a skin that is harder than the core. When you cut the EPS with a saw or knife, or sand it, you expose the softer core of the bubbles. If you cut with a heated wire it should form a new skin.
But yes, I trust you on the PVA and will try it out for sure. But will need to find something to make it moisture resistant. Perhaps just a thin coat of shellac, a spray fixative or water repellent?
Could you please help in choosing the DML speaker. Thinking of building a DML speaker running full range.
From the messages in the forum it seems we have below options for DML running full range:
1. Canvas of size: 16 by 12 inch, attached with a 3mm thick, 6 by 4 inch plywood. Exciter at the center of the plywood and plywood at the center of canvas. Coating canvas and plywood with diluted pva + water or acrilic paint + water , for stiffening.
2. Long plywood panel : 3-4mm thickness , long 1160mm , 300mm wide panel
10mm foam tape on long sides to fix the panel to frame
Please help to choose which would be better, or if we have any other better options than these 2.
Regarding Canvas panels please help regarding below queries :
Q. what if panel looses its stiffness over time , how to make it tight again? is it by spraying pva + water solution again? are Canvas DML good for long term usage or do we need to change to a newer stiffer canvas after a while of usage.
Q. which placement options would be good .. whether hang in front of us from a floor standing stand/frame , or hang from top of ceiling
Also which exciter would be preferable, from below:
1. Dayton Audio DAEX25Q-4
https://diyaudiocart.com/Raw-Driver...io-DAEX25Q-4-Quad-Feet-25mm-Exciter-20W-4-Ohm
2. Dayton Audio - DAEX32U-4
https://diyaudiocart.com/Raw-Driver...-Audio-DAEX32U-4-Ultra-32mm-Exciter-40W-4-Ohm
3. unnamed exciter from aliexpress :
https://www.aliexpress.com/item/4001024643762.html?spm=a2g0o.cart.0.0.4b4f3c00qx674l&mp=1
all 3 above have power handling of around 20w, and 1st and 3rd one have voice coil of 25mm and 2nd one having voice coil of 32mm.
From the messages in the forum it seems we have below options for DML running full range:
1. Canvas of size: 16 by 12 inch, attached with a 3mm thick, 6 by 4 inch plywood. Exciter at the center of the plywood and plywood at the center of canvas. Coating canvas and plywood with diluted pva + water or acrilic paint + water , for stiffening.
2. Long plywood panel : 3-4mm thickness , long 1160mm , 300mm wide panel
10mm foam tape on long sides to fix the panel to frame
Please help to choose which would be better, or if we have any other better options than these 2.
Regarding Canvas panels please help regarding below queries :
Q. what if panel looses its stiffness over time , how to make it tight again? is it by spraying pva + water solution again? are Canvas DML good for long term usage or do we need to change to a newer stiffer canvas after a while of usage.
Q. which placement options would be good .. whether hang in front of us from a floor standing stand/frame , or hang from top of ceiling
Also which exciter would be preferable, from below:
1. Dayton Audio DAEX25Q-4
https://diyaudiocart.com/Raw-Driver...io-DAEX25Q-4-Quad-Feet-25mm-Exciter-20W-4-Ohm
2. Dayton Audio - DAEX32U-4
https://diyaudiocart.com/Raw-Driver...-Audio-DAEX32U-4-Ultra-32mm-Exciter-40W-4-Ohm
3. unnamed exciter from aliexpress :
https://www.aliexpress.com/item/4001024643762.html?spm=a2g0o.cart.0.0.4b4f3c00qx674l&mp=1
all 3 above have power handling of around 20w, and 1st and 3rd one have voice coil of 25mm and 2nd one having voice coil of 32mm.
Sarath.
https://www.tectonicaudiolabs.com/audio-components/audio-exciters/
This is the closest to my exciter so it is the only one I can recommend.
There are similar exciters to this made by Dayton audio such as the 25 fhe 4 .
The art panel is a pretty good full range panel as long as you are not expecting to play pounding electronic rock ,they will not handle it well.
to be honest I would not run any dml panel full range .
Steve.
https://www.tectonicaudiolabs.com/audio-components/audio-exciters/
This is the closest to my exciter so it is the only one I can recommend.
There are similar exciters to this made by Dayton audio such as the 25 fhe 4 .
The art panel is a pretty good full range panel as long as you are not expecting to play pounding electronic rock ,they will not handle it well.
to be honest I would not run any dml panel full range .
Steve.
Good link Leob. Letting a side it is in German, it seems they ship "only" to Germany, Austria and Switzerland. Not to France.
He ships to Sweden as well, but prefers to communicate in German. I only know a little German myself, but Joseph was very helpful and we sorted out my additions and he got it shipped right away. I'm sure he can send anywhere in EU if you can manage the communication. I have a German wife to check with, but google translate should work.
Seems like he makes the plates himself using the raw materials from BASF.
I thought PVA was quite hygroscopic in general, but indeed there is water resistant wood glue which is still almost pure PVA!
Reading your post, I thought you had download it already. No problem
Go to this page : https://linearaudio.net/downloads where are the free Linear Audio ressource.
Go down or search for the file 30multitone_flat_48.wav
There are recommendations just before. The more important : set the recorder (REW) on the same sampling frequency 48kHz than the track and set the RTA on spectrum with a 65536 point FFT. This to avoid any artifact (unreal frequencies linked to window leakage) from the FFT treatement.
The characteristic of the signal is a 1/3 octave spacing but more important the random phase.
I also set the RTA on average forever as I do for MMM (Moving Microphone Measurement with pink noise) so that the noise floor is reduced by averaging but not the frequencies from the speaker.
I made a stereo track from the mono original one.
I play it with Audacity while REW is working in RTA.
Hi Steve,
thanks for the info.
so regarding the Canvas panels:
Q. what if panel looses its stiffness over time , how to make it tight again? is it by spraying pva + water solution again? are Canvas DML good for long term usage or do we need to change to a newer stiffer canvas after a while of usage.
Q. which placement options would be good .. whether hang in front of us near the floor from a floor standing stand/frame , or hang from top of ceiling
Sarath.
Are you not able to use a sub or LF driver ?
Will this be used with low power near field monitoring ?
Or are you intending to fill a large room will high volumes ?
I was, before being tempted will eps panels, going to try a larger ply panel in the centre , to see if this would prevent some of the buzzing from the large area of canvas ?
it is for me an on going project ,so can't guarantee high power performance.
If the exciter is properly mounted at the back ,there should be very little weight on the canvas itself ,so stretching should not be an issue, hopefully ?
but maybe only coating the back of the panel in pva (or other) would allow the front to be wetted with a sponge ,this would shrink , tighten the canvas a little ,maybe ?
If XO above 100hz ,there are more panel options.
Steve.
Are you not able to use a sub or LF driver ?
Will this be used with low power near field monitoring ?
Or are you intending to fill a large room will high volumes ?
I was, before being tempted will eps panels, going to try a larger ply panel in the centre , to see if this would prevent some of the buzzing from the large area of canvas ?
it is for me an on going project ,so can't guarantee high power performance.
If the exciter is properly mounted at the back ,there should be very little weight on the canvas itself ,so stretching should not be an issue, hopefully ?
but maybe only coating the back of the panel in pva (or other) would allow the front to be wetted with a sponge ,this would shrink , tighten the canvas a little ,maybe ?
If XO above 100hz ,there are more panel options.
Steve.
Hi Steve,
Room size is around 16 * 12 feet, and sound volume would not be party level high..
Yet to build any speakers so far and currently its only TV speakers running here.
earlier planned to build 'frugal horn speaker' with mark audio alpair 7p drivers.. got the drivers but could not continue to build for long ..
now looking at the simplicity , ease/cost of build , and good sound feedback of DMLs, getting tempted again to build own speakers ..
ya may be in future need to plan for a compact subwoofer also ..
Sarath.
At the moment I am in the middle of testing the eps panels.
The first picture is the low grade panel drying near the fire after coating with pva.
The second picture is them playing before coating.
The third picture is the response of the 70grade eps panel before doing anything to it.
The fourth picture is the low grade panel before doing anything to it.
Both at about 30cm.
The peak before rolling off with the low grade is at about 8k.
And the peak before rolling off with the 70grade is about the 13k mark.
I will explain the difference in sound and performance at another time, as I have noticed certain things as I've moved along.
Steve.
At the moment I am in the middle of testing the eps panels.
The first picture is the low grade panel drying near the fire after coating with pva.
The second picture is them playing before coating.
The third picture is the response of the 70grade eps panel before doing anything to it.
The fourth picture is the low grade panel before doing anything to it.
Both at about 30cm.
The peak before rolling off with the low grade is at about 8k.
And the peak before rolling off with the 70grade is about the 13k mark.
I will explain the difference in sound and performance at another time, as I have noticed certain things as I've moved along.
Steve.
Attachments
I took this picture to show the difference a poor quality grade can make.
You can see the holes in the surface ,both panels have the holes , but the holes in the higher grade are smaller.
These are just cheap packing boards, this was similar to the cheap panels wickes started selling , but are back to the good quality stuff now, in my local shop anyway ?
They still sound good though, but I don't like the idea of mounting my exciter on a panel full of holes.
I didn't bother sanding the low grade panel as the soft surface didn't sound bad , but the 70grade even though it did feel softer ,still had that eps sound, so I sanded it, what a pain !
At the moment they both sound very similar.
I will continue to listening to them for a little while before making some more alterations.
Steve.
You can see the holes in the surface ,both panels have the holes , but the holes in the higher grade are smaller.
These are just cheap packing boards, this was similar to the cheap panels wickes started selling , but are back to the good quality stuff now, in my local shop anyway ?
They still sound good though, but I don't like the idea of mounting my exciter on a panel full of holes.
I didn't bother sanding the low grade panel as the soft surface didn't sound bad , but the 70grade even though it did feel softer ,still had that eps sound, so I sanded it, what a pain !
At the moment they both sound very similar.
I will continue to listening to them for a little while before making some more alterations.
Steve.
Attachments
One of the first things I noticed when first listening to the uncoated panels and comparing them to the 6ft sanded panel,was that the cheap 70grade panel sounded boxy in the lower midrange a sort of resonance.
It was very obvious, I was wondering if this was the sort of echo Eric was describing ?
Sanding reduced this considerably and since adding the pva I have not noticed it, it now has a very clean clear sound.
The pva will take a few days to harden properly, so the HF might still improve a little more ?
Jangling bells and crashing bells already sound good though, eps always excels at this , and the ambience is excellent.
I am enjoying this .
The picture I of the 70grade with pva , it looks very similar to the eps skin but the sound is totally different.
Steve.
It was very obvious, I was wondering if this was the sort of echo Eric was describing ?
Sanding reduced this considerably and since adding the pva I have not noticed it, it now has a very clean clear sound.
The pva will take a few days to harden properly, so the HF might still improve a little more ?
Jangling bells and crashing bells already sound good though, eps always excels at this , and the ambience is excellent.
I am enjoying this .
The picture I of the 70grade with pva , it looks very similar to the eps skin but the sound is totally different.
Steve.
