Yes, not my favourite speakers at all, but they do have a pretty good grasp about what they're doing - I think the guys at Green Mountain Audio seem to be able to do a pretty good job for reasonable cost effective materials and build, as was mentioned up above, I think.
It's curious that I have found that the Polymers/Concrete mixture is quite suitable for the bass baffles (or curved front panels) up to about 150Hz (with a CLD chipbrd box) but have some difficulties with resonance control/damping combinations for the mids/top drivers - or at least, with high efficiency drivers that I use.
I prefer the "colour" of timber "baffles" with poly-concrete chambers for the FR drivers above 120Hz anyway - I tried the idea of "floating" the baffle with concrete mass loading, and such things, but not really satisfactory for me - not sure if any of this applies elsewhere.
I'm looking forward to the day when that electric/magnetic polymer foam becomes commercially available so can "dial in" our damping freq response via external power supply/amplifier - I noticed a concept about it in 'aero noise control/design' but not much since.
And nothing much about the bass 'tuned bass plate absorbers' (can't think of their name, darnit!) for internal bass damping either (for more critically controlled bandpass damping), but I do see a bit of a start with the incorporation of the 'anti-resonance wells/holes' in the pole peices for midrange peak cancellation - hopefully, the new design programs will enable some of these more esoteric ideas to become readily available.
I think the day has nearly arrived when speaker driver and chamber design has finally left the domain of 'craft' - looking forward to the extension of these programs to include the "less than precisely defined characteristics of amplifier design" to marry up to them.
It's curious that I have found that the Polymers/Concrete mixture is quite suitable for the bass baffles (or curved front panels) up to about 150Hz (with a CLD chipbrd box) but have some difficulties with resonance control/damping combinations for the mids/top drivers - or at least, with high efficiency drivers that I use.
I prefer the "colour" of timber "baffles" with poly-concrete chambers for the FR drivers above 120Hz anyway - I tried the idea of "floating" the baffle with concrete mass loading, and such things, but not really satisfactory for me - not sure if any of this applies elsewhere.
I'm looking forward to the day when that electric/magnetic polymer foam becomes commercially available so can "dial in" our damping freq response via external power supply/amplifier - I noticed a concept about it in 'aero noise control/design' but not much since.
And nothing much about the bass 'tuned bass plate absorbers' (can't think of their name, darnit!) for internal bass damping either (for more critically controlled bandpass damping), but I do see a bit of a start with the incorporation of the 'anti-resonance wells/holes' in the pole peices for midrange peak cancellation - hopefully, the new design programs will enable some of these more esoteric ideas to become readily available.
I think the day has nearly arrived when speaker driver and chamber design has finally left the domain of 'craft' - looking forward to the extension of these programs to include the "less than precisely defined characteristics of amplifier design" to marry up to them.
Nice Mexican enclosure for a speaker. 
An externally hosted image should be here but it was not working when we last tested it.
I had lunch with my cousin today. He owns a very large asphalt paving company here in Michigan. We were talking about concrete speakers and he suggested mixing concrete with the rubber additive that he uses when paving running tracks. It is ground up rubber from a number of recycled sources. I thought that was a good idea.
Why it was a good idea? What do you mix MDF with?
I prefer to mix with gravel of random sizes, shapes and density. It is deaf like in a grave; those who tried this practically would laugh about all that theoretical musings.
It would be great to ask those who deal with it how to make it more technological. Results are great, but all processes that I tried are PITA.
I prefer to mix with gravel of random sizes, shapes and density. It is deaf like in a grave; those who tried this practically would laugh about all that theoretical musings.
It would be great to ask those who deal with it how to make it more technological. Results are great, but all processes that I tried are PITA.
I also used some of the crumbed rubber with a mix of various gravels plus some scoria to get the weight down a bit and included quite a lot of the polymers - not the easiest mixture to handle and, as Anatoliy mentioned, a bit of a PIA even with a vibration table - works well when I got it right for the bass driver and not quite right for the mid/top chamber.
It is I am sorry, if my English sounds rude. I mean, can you ask him please about some technologies to make enclosures without PITA?
I made some, they sound increadibly great. But I would hesitate to repeat that experiments once more.
People think that since concrete is cheap cabinets should be cheaper than made from MDF. How wrong...
Adding polymers as James is suggesting could change the equation. Anyone know about water compatible additives? How about not basic concrete, but the industrial parching materials that have bonding agents or the surfacing materials used for faux stone? Some of them don't shrink and can bond to your form. Why not skip the cement and just look at fillers to resins? Powers, grains, fibers of various properties.
Powered rubber is used in concrete for things like bridge decking to give it more resistance to thermal cycling. No idea what it does to the properties we may be looking for.
Has anyone else taken a look at a someplace like McMaster Carr or industrial suppliers to look at the wide range of materials that are available? You know, ones that are machinable, durable, and where one could select the properties.
I was dumping the contents of my dust collector and was wondering what kind of properties sawdust mixed with resin would produce. I know West System has resins with a wide variety of hardness above and below polyester resin. Of course, when you reach about 99.5% sawdust, you get MDF again.
Powered rubber is used in concrete for things like bridge decking to give it more resistance to thermal cycling. No idea what it does to the properties we may be looking for.
Has anyone else taken a look at a someplace like McMaster Carr or industrial suppliers to look at the wide range of materials that are available? You know, ones that are machinable, durable, and where one could select the properties.
I was dumping the contents of my dust collector and was wondering what kind of properties sawdust mixed with resin would produce. I know West System has resins with a wide variety of hardness above and below polyester resin. Of course, when you reach about 99.5% sawdust, you get MDF again.
However if you want some outdoor speakers for the winter time you could make them out of Pykrete.
14% Sawdust 86% water, by weight.
Pykrete - Wikipedia, the free encyclopedia
Those who watch Mythbusters know that they were once going to build an aircraft carrier from the stuff.
14% Sawdust 86% water, by weight.
Pykrete - Wikipedia, the free encyclopedia
Those who watch Mythbusters know that they were once going to build an aircraft carrier from the stuff.
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I myself have not sen uglier loudspeakers, But I did not hear better results obtained from dynamic drivers in closed enclosures.
It is like medicine, the nastier it tastes the better you think it is working
It is like medicine, the nastier it tastes the better you think it is working
Thank you for fair judgment of my tastes.
Actually, the shape of that speakers remind shape of this car: in that experiment I tried to avoid all possible causes of resonances.
An externally hosted image should be here but it was not working when we last tested it.
Not cement but clearly an interesting and economical solution to wave diffusion.
These are papier mache from old console.
[URL=http://imageshack.us/photo/my-images/577/t2ec16dhjiye9quco3l2bps.jpg/][IMGDEAD]http://img577.imageshack.us/img577/3209/t2ec16dhjiye9quco3l2bps.jpg[/IMGDEAD][/URL]
Uploaded with [URL=http://imageshack.us]ImageShack.us[/URL]
These are papier mache from old console.
[URL=http://imageshack.us/photo/my-images/577/t2ec16dhjiye9quco3l2bps.jpg/][IMGDEAD]http://img577.imageshack.us/img577/3209/t2ec16dhjiye9quco3l2bps.jpg[/IMGDEAD][/URL]
Uploaded with [URL=http://imageshack.us]ImageShack.us[/URL]
That looks like the paper cups on the backs of the midrange units in an old Cerwin Vega I've got hanging around here.
Thank you for fair judgment of my tastes.
Actually, the shape of that speakers remind shape of this car: in that experiment I tried to avoid all possible causes of resonances.
And that is a beautiful car.
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Or egg carton cups. Thought they were those faux stone garden speakers sold at
Parts Express when I first so them
This idea is more accessable to me, since my place of work has a machine shop for cutting, routing and profiling of phenolic linen, phenolic ply and grp sheet material. The cost of the raw stock is my main obstacle.
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Joined 2009
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Thank you for fair judgment of my tastes.
Actually, the shape of that speakers remind shape of this car: in that experiment I tried to avoid all possible causes of resonances.
An externally hosted image should be here but it was not working when we last tested it.
forget audio speakers, I'll take that car ANY DAY over a speaker - I bet it sounds gorgeous
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