hello
i am quite new to this ball game and could use some basic info.
so far i have seen that just about everyone uses mdf of some relitive in there cabinet construction, exept if you go all the way to the wilson line and find that they are casting thers out of corian.this casting approach is very appealing but the cost of polyester resin is not.
i have heard others talking of the deadness of a mateirial or it's stability.this i can kind of understand,but is there a way to measure it.if i knock on a corian counter it feels dead but if i knock on a chunk of concrete it feels much deader,so why not cast cabinets out of something like concrete.
i fully realize that this could be a very boring question with a very simple answer,please enlighten me.
thank you
i am quite new to this ball game and could use some basic info.
so far i have seen that just about everyone uses mdf of some relitive in there cabinet construction, exept if you go all the way to the wilson line and find that they are casting thers out of corian.this casting approach is very appealing but the cost of polyester resin is not.
i have heard others talking of the deadness of a mateirial or it's stability.this i can kind of understand,but is there a way to measure it.if i knock on a corian counter it feels dead but if i knock on a chunk of concrete it feels much deader,so why not cast cabinets out of something like concrete.
i fully realize that this could be a very boring question with a very simple answer,please enlighten me.
thank you
Hi Yosh,
DIYers have cast speaker cabinets out of concrete quite a few times. Concrete is hardly ever used by commercial manufacturers because of the weight and associated shipping costs. Bespoke concrete cabinet makers appear from time to time but serve only their local areas. Last one I came across was in Wales.
James
DIYers have cast speaker cabinets out of concrete quite a few times. Concrete is hardly ever used by commercial manufacturers because of the weight and associated shipping costs. Bespoke concrete cabinet makers appear from time to time but serve only their local areas. Last one I came across was in Wales.
James
is the weight the only problem with a concrete like material or does it have some overwhelming shortcoming.like i said before i like the idea of casting one piece cabinets (myself having allot of experience in mold making and concrete) but the time involved in making the mold would be great.could concrete being full of bentonite just like corian make it suitable substitute.
Concrete has the tendancy to crack over time as it dries and it is very hard to mount the drivers unless you use an inset of wood or something workable to hold the driver in the cabinet. Cast Corian is great but beyond expensive. Making a box of sheet Corian has only some of its advantages and lots of the same problems of wood. A fine plaster / resin combo with lots of fiberglass or Kevlar threads would be nice. Remember the volume shrinks as it dries for most plasters. I've made the sheet Corian boxes out of remnants before with beter than wood/mdf results but you must damp the insides for high freq reflectivity as sound bounces right off the surface of Corian.
Yosh, ten years ago I built some truncated tubes out of 2" thick concrete, 3.5" mdf baffles, lots of lead shot, Liquid Nails and Black Hole Pad.
Made the inside surfaces irregular to alleviate standing wave issues and stuffed it with plenty of long-hair wool.
Plopped a 6.5" Dynaudio 17W75EXT in it and a Linnaeum dipole tweeter on top, simple passive XO---my it sure sounds sweet!
Incredibly taught and well-defined bass for such a small driver; therein lies the main advantage of using concrete, in my opinion.
I've also read elsewhere that concrete is not so good for midrange enclosures but for bass frequencies it's great.
It's also a pain to work with and carcinogenic (dust). Do a google search on concrete speakers--I think a fellow named Darren or Daryl Kuma (or possibly different spelling--sri I can't remember) has a big website with lots of good concerete speaker info (no pun intended
.
Also search this site for "Corian"--there is an outfit that will sell all types of Corian to us DIYers. Unlike concrete, it can be shaped, cut and routed for a multitude of uses in speaker building. I'm currently in the planning/acquisition stage of building a variation of Orion-type dipoles and am considering reinforcing them with Corian. I'll be posting pictures and details once I've made some progress later this summer.
Cheers, Jeff
Made the inside surfaces irregular to alleviate standing wave issues and stuffed it with plenty of long-hair wool.
Plopped a 6.5" Dynaudio 17W75EXT in it and a Linnaeum dipole tweeter on top, simple passive XO---my it sure sounds sweet!
Incredibly taught and well-defined bass for such a small driver; therein lies the main advantage of using concrete, in my opinion.
I've also read elsewhere that concrete is not so good for midrange enclosures but for bass frequencies it's great.
It's also a pain to work with and carcinogenic (dust). Do a google search on concrete speakers--I think a fellow named Darren or Daryl Kuma (or possibly different spelling--sri I can't remember) has a big website with lots of good concerete speaker info (no pun intended
. Also search this site for "Corian"--there is an outfit that will sell all types of Corian to us DIYers. Unlike concrete, it can be shaped, cut and routed for a multitude of uses in speaker building. I'm currently in the planning/acquisition stage of building a variation of Orion-type dipoles and am considering reinforcing them with Corian. I'll be posting pictures and details once I've made some progress later this summer.
Cheers, Jeff
the top left (1982) is made of concrete:
http://www.rauna.com/slides/
And Yes - deay did crack after some years and was har to produce. Sound - well interesting. There are many aspects to laoudspeaker system building but these had some very good sides without beeing spectacular by any means.
I have been thinking for a while about making something aout of concrtete myself.
/j
http://www.rauna.com/slides/
And Yes - deay did crack after some years and was har to produce. Sound - well interesting. There are many aspects to laoudspeaker system building but these had some very good sides without beeing spectacular by any means.
I have been thinking for a while about making something aout of concrtete myself.
/j
i was thinking along the lines of nano tubes .a very small fiber with incredible strength if mixed correctly.it would surely be possible to incorperate integral braces to lessen the liklyhood of cracking. there are deffinatly many ways to approach the cracking issue. how about casting surface baffles in the walles,like those angular things i see in sound rooms?
Steel rods or mesh are used to reinforce concrete because it expands and contracts with temperature with the same coefficient that the concrete itself does. Without this relationship current construction methods using concrete would be impossible. Concrete doesn't dry, it cures. In fact, it takes many years and is still getting harder as the exterior starts to deteriorate from exposure to the elements.
If a concrete speaker develops cracks after a few years then it is from 1. An improper mix 2. An insufficient curing time 3. A poor grade of concrete was used and/or 4. It was inadequately reinforced.
If a concrete speaker develops cracks after a few years then it is from 1. An improper mix 2. An insufficient curing time 3. A poor grade of concrete was used and/or 4. It was inadequately reinforced.
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