Alius123
Sorry to hear about your receiver ,sh#t happens.
The exciter you are using is way over powered and heavy for low grade eps a single exciter in the 10watt to 25watt 1inch variety and below 100grms would drive 1inch eps to horrendously loud volumes,without frames or bracing .
Your heavy exciter ,with time will probably rip the eps beads from the panel unless properly supported.
If the exciter is heavier than the panel ,you could mount the exciter on a stand and glue the panel to the exciter, with a soft foam as support at the bottom or on the stand,so that the panel would be free floating .
As you have pointed out ,at low frequencies the eps will be vibrating like crazy and become uncontrollable,it would be best ,in my opinion ,to keep these frequencies well away from the eps.
Removing the bad sounding eps skin and replacing with pva,is a must for a good natural sounding panel,you don't have to get too carried away,scuffing the surface so that the 50x50 pva mix soaks into the eps is all that is needed,it is a messy job,easier on smaller panels.
Eps has a very dynamic sound very exciting,similar to horn loading and is also very efficient,heavier panels are ,for want of a better word, are more restrained,not sure if this came across in my recordings.
It all depends on your tastes.
Other coatings can be added to further reduce colorations but will also reduce dynamics.
Steve
Sorry to hear about your receiver ,sh#t happens.
The exciter you are using is way over powered and heavy for low grade eps a single exciter in the 10watt to 25watt 1inch variety and below 100grms would drive 1inch eps to horrendously loud volumes,without frames or bracing .
Your heavy exciter ,with time will probably rip the eps beads from the panel unless properly supported.
If the exciter is heavier than the panel ,you could mount the exciter on a stand and glue the panel to the exciter, with a soft foam as support at the bottom or on the stand,so that the panel would be free floating .
As you have pointed out ,at low frequencies the eps will be vibrating like crazy and become uncontrollable,it would be best ,in my opinion ,to keep these frequencies well away from the eps.
Removing the bad sounding eps skin and replacing with pva,is a must for a good natural sounding panel,you don't have to get too carried away,scuffing the surface so that the 50x50 pva mix soaks into the eps is all that is needed,it is a messy job,easier on smaller panels.
Eps has a very dynamic sound very exciting,similar to horn loading and is also very efficient,heavier panels are ,for want of a better word, are more restrained,not sure if this came across in my recordings.
It all depends on your tastes.
Other coatings can be added to further reduce colorations but will also reduce dynamics.
Steve
Thanks for the advice Steve. It’s interesting you mention the ultra being too overpowered. I specifically picked that exciter because of reading on threads in parts express that it was better suited for lighter panels, though finicky in build quality. After my short experimentation I would a have to agree that it definitely doesn’t seem underpowered as I’ve read by some. I would hate to see how powerful the thrusters are though! Especially since the ultra exciter is made with plastic as opposed to metal.
Also, is it possible to sand EPS without just crumbling it? I can see sanding XPS but the EPS foam is more granular in material.
Thanks again! I do appreciate the suggestions and will definitely look at implementing a frame once I can test out what I want exactly.
Also, is it possible to sand EPS without just crumbling it? I can see sanding XPS but the EPS foam is more granular in material.
Thanks again! I do appreciate the suggestions and will definitely look at implementing a frame once I can test out what I want exactly.
Honeycomb cardboard
I‘ve recently found at a recycling corner two panels of honeycomb cardboard with a thickness of 18mm. When knocking on it with the finger tipp it produces a better resonance in the low end than my 13mm panel. Will give it a try.
Alius123
My bad,I got the u4 mixed up with the ep exciter,but looking at the specs I see that your u4 is only 8grms lighter than the 40watt ep exciter ?
My 10 watt exciters are only 85grams the u4 is 140grams,I also noticed that the exciter is totally encapsulated in a plastic shell , including the suspension and removable coil foot.
I bought the hdn8 which is enclosed in a plastic shell for outside use ,this shell resonates badly, which makes it unusable for me,bad design!
I can only hope the u4 doesn't suffer from this.
As for sanding eps,you must only gently scuff the surface, breaking up the hard skin so that the surface feels soft ,a bit like felt,this surface will readily absorbe the 50x50 mix.
On very large panels this is a pain,and very dusty,I have a large panel that I never got round to coating, every time I played this panel it left a white line on the floor.
I don't know which grade you have ,but the lower grades have a much softer surface , which can be coated without sanding.
I will be testing these lower grades to see how they compare,I will only be using 1cm thickness and the panel size about 50x60cm or smaller,we shall see.
I known the HF will roll off above 10k with the soft eps ,but hopefully I can sort something out.
Steve
My bad,I got the u4 mixed up with the ep exciter,but looking at the specs I see that your u4 is only 8grms lighter than the 40watt ep exciter ?
My 10 watt exciters are only 85grams the u4 is 140grams,I also noticed that the exciter is totally encapsulated in a plastic shell , including the suspension and removable coil foot.
I bought the hdn8 which is enclosed in a plastic shell for outside use ,this shell resonates badly, which makes it unusable for me,bad design!
I can only hope the u4 doesn't suffer from this.
As for sanding eps,you must only gently scuff the surface, breaking up the hard skin so that the surface feels soft ,a bit like felt,this surface will readily absorbe the 50x50 mix.
On very large panels this is a pain,and very dusty,I have a large panel that I never got round to coating, every time I played this panel it left a white line on the floor.
I don't know which grade you have ,but the lower grades have a much softer surface , which can be coated without sanding.
I will be testing these lower grades to see how they compare,I will only be using 1cm thickness and the panel size about 50x60cm or smaller,we shall see.
I known the HF will roll off above 10k with the soft eps ,but hopefully I can sort something out.
Steve
I should also mention that the higher grades are much more robust and easier to sand without breaking up,but ordering hi grade eps is expensive in small quantities.
If I wanted a large full range panel with 20hzto 20k response,I would use UH grades,even my 10watt exciter would drive this panel.
Even a small 50cm panel will do 40hz to 20k no problem.
Steve
If I wanted a large full range panel with 20hzto 20k response,I would use UH grades,even my 10watt exciter would drive this panel.
Even a small 50cm panel will do 40hz to 20k no problem.
Steve
From what I can find online, types of EPS are defined by density and sometimes re-grind content.
Only the cheapest stuff has re-grind content.
I can't seem to find any EPS labeled UH, do you know which density the EPS you define as UH has?
Cheers
Andreas
Yeah I definitely got low grade. Mine is R4, and I noticed that one said High Density was R10. It is defiantly much more expensive for HD. I got my low grade stuff for 9 bucks, compared to the HD stuff here https://www.homedepot.com/p/Amvic-M...-x-24-in-x-48-in-5-Panels-AMDKIT001/301619814
That makes more sense, I'm able to find the stuff used for insulation in buildings, where i'm from these are graded in kilo-pascal (kPa), the amount of tonnes pressure over 1 sqm, the cheap stuff is 60 and the denser stuff is 150, 250, 300 and 400..
the density for 60 kPa is 13 kg/m3, for 250 it's 33 kg/m3, for 400 it's 50kg/m3.
just comparing density, a XPS 300 kPa panel is 30kg/m3, which means XPS is lighter when comparing only pressure strength.
for DML It has been argued the property that is more important is bending strength, but for the construction stuff that is not listed in the manufacturer I've come across.
I'd like to pose the question: have anyone compared EPS to XPS using panels that's close to the same density?
Alius.
I have found the different names confusing ,depending on where you live.could r4 be 40 grade and r10 100grade? Does the surface of your panel feel soft?
Custompac grades go from 40 to 150, if you go as high as 400 you are probably talking of hard plastic ,not recommend.
I have mainly used 70 grade from the local diy store,very cheap,was about £7 for 8ftx4ft 1inch ,quality can vary ,too many holes in the surface.
Zigadr (RIP) over on nxt rubbish on audio circle,used something like 100 to 150 grade(not sure) And a very large panel 1cm thick ,with very good results.
I have thought of using the 50watt exciter as a discus and throwing it down the garden!!
Steve
I have found the different names confusing ,depending on where you live.could r4 be 40 grade and r10 100grade? Does the surface of your panel feel soft?
Custompac grades go from 40 to 150, if you go as high as 400 you are probably talking of hard plastic ,not recommend.
I have mainly used 70 grade from the local diy store,very cheap,was about £7 for 8ftx4ft 1inch ,quality can vary ,too many holes in the surface.
Zigadr (RIP) over on nxt rubbish on audio circle,used something like 100 to 150 grade(not sure) And a very large panel 1cm thick ,with very good results.
I have thought of using the 50watt exciter as a discus and throwing it down the garden!!
Steve
Andreas.
To me, the most important thing is how does the material sound,and as far as rigidity is concerned ,this would depend on the size of the panel.
Come to think of it,I think zigadr used VH grade eps,but what that grade is in Australia ,I have no idea?
Having the higher grade let's you use thinner panels,as long as the eps is still in lighter beaded form,not solid.
Steve
To me, the most important thing is how does the material sound,and as far as rigidity is concerned ,this would depend on the size of the panel.
Come to think of it,I think zigadr used VH grade eps,but what that grade is in Australia ,I have no idea?
Having the higher grade let's you use thinner panels,as long as the eps is still in lighter beaded form,not solid.
Steve
Honeycomb cardboard
The 18mm panel (size is equal to my 13mm panel) weights 255gr (13mm is 480gr) and is less strength when applying pressure to the surface. Probably it is more a honeycomb paperboard than cardboard. I've mounted the exciter the same way and did a short listening. The tonal balance seems better for me. Voices, trumpets in the midband are very naturally. Piano in the region of 1 - 2 kHz has sometimes coloration and details overall are not that surprisingly as with the 13mm panel. The frequency range looks quite similar.
I'm now soaking the 18mm panel on one side with snake oil (vegan) from my kitchen and will do the other side as well.
The 18mm panel (size is equal to my 13mm panel) weights 255gr (13mm is 480gr) and is less strength when applying pressure to the surface. Probably it is more a honeycomb paperboard than cardboard. I've mounted the exciter the same way and did a short listening. The tonal balance seems better for me. Voices, trumpets in the midband are very naturally. Piano in the region of 1 - 2 kHz has sometimes coloration and details overall are not that surprisingly as with the 13mm panel. The frequency range looks quite similar.
I'm now soaking the 18mm panel on one side with snake oil (vegan) from my kitchen and will do the other side as well.
I agree about the size, I'll try both when I get to that point, I can get 60 down to 10mm and 250 in 20 mm as the flattest, both 600x1200mm. both are fairly cheap.
Andraes.
If I was paying for it ,I would be a little worried that the panel was getting a little heavy,but it would be interesting to find out how the 250 grade sounds.
for my 10watt exciters I probably would have gone for the 100 or 150 grade for lightness and strength and flexibility in the 1cm thickness .
But if as you say,you can get it cheaply,go for it.
The 250 grade you suggest should also support the heavier more powerful exciters.
Steve
If I was paying for it ,I would be a little worried that the panel was getting a little heavy,but it would be interesting to find out how the 250 grade sounds.
for my 10watt exciters I probably would have gone for the 100 or 150 grade for lightness and strength and flexibility in the 1cm thickness .
But if as you say,you can get it cheaply,go for it.
The 250 grade you suggest should also support the heavier more powerful exciters.
Steve
I'm curious too! Expensive is relative, the cheap 10mm is 1.5 euro per panel and the 250 is 5, when sold separately. Bulk is naturally cheaper.
Its cheaper to try out then ply and honeycomb cardboard, and will be good to have as reference.
I would probably get both in 20mm to better compare.
Alius: cool, whats the grade?
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Alius.
Your eps LOOKS very similar to my original eps panels,the good stuff without holes in the surface,is the surface quite hard ,with a bright sound when scratched with your nails?
This material will go very loud with only a few watts,my 8watt t amp handles this with ease.
The panel looks quite narrow what is the size?
Andreas.
Wow ,that is cheap ,I have to buy the 8x4ft and cut it to size myself to match that price,which is a pain!
But the store has the eps only in the lower grade,you can order higher grades on line but the transport costs are excessive.
Buying 20panels isn't much different in price than buying 2 !!,not far off £100.
If anyone sees high grade eps in the UK sold cheaply ,p!ease let me know
Steve
Your eps LOOKS very similar to my original eps panels,the good stuff without holes in the surface,is the surface quite hard ,with a bright sound when scratched with your nails?
This material will go very loud with only a few watts,my 8watt t amp handles this with ease.
The panel looks quite narrow what is the size?
Andreas.
Wow ,that is cheap ,I have to buy the 8x4ft and cut it to size myself to match that price,which is a pain!
But the store has the eps only in the lower grade,you can order higher grades on line but the transport costs are excessive.
Buying 20panels isn't much different in price than buying 2 !!,not far off £100.
If anyone sees high grade eps in the UK sold cheaply ,p!ease let me know
Steve
The company that sells the high grade stuff individually is a flooring company, as this stuff is used in floor insulation. you could start looking there.