mijostyn:
Thanks. If the OP builds one of these he will not be disappointed.
The best rack is of course no rack at all. For years my turntable sat on the floor. Try it, you will find it is very hard to do better. Very hard.
The way I see it there are three kinds of vibration a good turntable rack has to somehow control. Most of the vibration in a good quiet listening room is from the turntable itself. But we don’t listen quietly, its sometimes quite loud, and so the rack has to control a lot of acoustic vibration. Finally there’s the floor moving around.
Trying to "isolate" all this turns out to be a waste of time. Mostly because of #1 and #2: the turntable itself and the music you’re playing are the two main sources of vibration. So even if your theoretical magical mystical powers extend all the way to anti-gravity morphic fields you still have only eliminated one- and the least one of them at that.
This is why all the very best stands are super solid and stiff. No one makes a six dimensions rack. Even if there were six dimensions, the one guy who never will stop bragging about it never has made more than the one contraption, and gosh I wonder why? http://www.machinadynamica.com/machina24.htm
Lotta work just to wind up right back where you started, having made no progress whatsoever in dealing with the sonic vibrations generated by the speakers or even the component itself. In fact it seems likely to have made them all even worse.
Now the concrete I used is in fact pretty awful in terms of vibration control. Cast a shelf like I did, you will be very disappointed. Because when you hit it, it vibrates. Rings, even. Granite slab, ditto. Might not think this would be the case. Well, a lot of things people think turn out not to be true or work in practice. (see: machinadynamica link above)
Concrete however still has a couple advantages. Concrete is massive. Super stiff. And dirt cheap. Cast creatively in a curved mold like I did, and painted, it even looks pretty good. Connecting the shelves with concrete-filled ABS and all bolted together eliminates most of the ringing.
Most however is not all. The vibration that remains however is all pretty high in frequency. Bed of sand (mixed with a little oil to keep it all neat and tidy and eliminate dust) easily eliminates all the ringing.
So what we have at this point is a super-stiff, super-massive stand pretty much impervious to sonic vibrations, like from music. Yes it will move if you stomp around right next to it. But because it is so massive it moves only at a very low fundamental frequency. A frequency that can actually be tuned, if you want to go to the trouble, either by working through the math, or even by trial and error, adding/removing sand, adding/removing a granite plate, making the shelves different thicknesses. All of which can be done for cheap, and even fairly easily due to the modular nature of the design.
Okay. So now we are left with only the vibrations of the turntable itself. At this point you can use whatever shelf you like. The best I ever heard are BDR, which is what I use. But the rack itself is so solid and stable you could get great results sitting the turntable right on the granite, or even on a sheet of plain old MDF. Remember the top shelf is a sand bed with about an inch of sand. So super stable no matter what you put on it.
Couple bags of concrete, reinforced with a little wire mesh, couple feet of ABS, dozen or so bolts, bag of sand, you could use whatever paint you want and still be way under $100.
Way to go millercarbon:)
Thanks. If the OP builds one of these he will not be disappointed.
The best rack is of course no rack at all. For years my turntable sat on the floor. Try it, you will find it is very hard to do better. Very hard.
The way I see it there are three kinds of vibration a good turntable rack has to somehow control. Most of the vibration in a good quiet listening room is from the turntable itself. But we don’t listen quietly, its sometimes quite loud, and so the rack has to control a lot of acoustic vibration. Finally there’s the floor moving around.
Trying to "isolate" all this turns out to be a waste of time. Mostly because of #1 and #2: the turntable itself and the music you’re playing are the two main sources of vibration. So even if your theoretical magical mystical powers extend all the way to anti-gravity morphic fields you still have only eliminated one- and the least one of them at that.
This is why all the very best stands are super solid and stiff. No one makes a six dimensions rack. Even if there were six dimensions, the one guy who never will stop bragging about it never has made more than the one contraption, and gosh I wonder why? http://www.machinadynamica.com/machina24.htm
Lotta work just to wind up right back where you started, having made no progress whatsoever in dealing with the sonic vibrations generated by the speakers or even the component itself. In fact it seems likely to have made them all even worse.
Now the concrete I used is in fact pretty awful in terms of vibration control. Cast a shelf like I did, you will be very disappointed. Because when you hit it, it vibrates. Rings, even. Granite slab, ditto. Might not think this would be the case. Well, a lot of things people think turn out not to be true or work in practice. (see: machinadynamica link above)
Concrete however still has a couple advantages. Concrete is massive. Super stiff. And dirt cheap. Cast creatively in a curved mold like I did, and painted, it even looks pretty good. Connecting the shelves with concrete-filled ABS and all bolted together eliminates most of the ringing.
Most however is not all. The vibration that remains however is all pretty high in frequency. Bed of sand (mixed with a little oil to keep it all neat and tidy and eliminate dust) easily eliminates all the ringing.
So what we have at this point is a super-stiff, super-massive stand pretty much impervious to sonic vibrations, like from music. Yes it will move if you stomp around right next to it. But because it is so massive it moves only at a very low fundamental frequency. A frequency that can actually be tuned, if you want to go to the trouble, either by working through the math, or even by trial and error, adding/removing sand, adding/removing a granite plate, making the shelves different thicknesses. All of which can be done for cheap, and even fairly easily due to the modular nature of the design.
Okay. So now we are left with only the vibrations of the turntable itself. At this point you can use whatever shelf you like. The best I ever heard are BDR, which is what I use. But the rack itself is so solid and stable you could get great results sitting the turntable right on the granite, or even on a sheet of plain old MDF. Remember the top shelf is a sand bed with about an inch of sand. So super stable no matter what you put on it.
Couple bags of concrete, reinforced with a little wire mesh, couple feet of ABS, dozen or so bolts, bag of sand, you could use whatever paint you want and still be way under $100.