How to soundproof my turntable?


Jonathon Carr recently mentioned here the importance of isolating your tt from airborne vibration, a project that has been on my mind for some time.

My tt sits in a custom cabinet. The left and back sides are drywall, the right side 3/4" plywood, the top and bottom 2" plywood, and the front is open. The shelf the tt sits on has holes for the wires to pass through. Overall dimensions are about 2.5' high, 2.5' deep, and 4' wide.

Over the weekend my friend and I built a 3/4" plywood door to cover the opening. There was a clear improvement when the door was in place. Now I want to make a better and permanent door.

I called up this company to ask their advice.

>http://www.soundproofing.org/sales/prices.html


They suggested 3/8" acrylic door with their 1" soundproofing foam mat on one or both sides. They said for the acrylic 1/4" is too thin and there is minimal improvement with 1/2".

The also suggested lining the inside of the cabinet with the same stuff. They make a 1/8" tape that can be used as a weather seal for the door.

They said any cracks or openings like the holes for the cable are very bad. A 1" hole can reduce absorption by 50%. Plugging the holes and cracks with their tape or foam they said is effective.

Anybody have any other ideas or suggestions for soundproofing this space?

I am also thinking about making the turntable cabinet a Faraday cage, ie, lining the cabinet with thin copper mesh. Anyone have any experience if this is worth the trouble or not?

Thanks.
george_a
Usually, having a lid on a turntable degrades the sound. But the usual lid is not constructed the way you are doing it. I think you are attacking from the wrong direction, you say nothing about what the base of the table is sitting on or even what table you are using. The effect of vibrations IN THE AIR on the arm has never been a concern to anyone to my knowledge. The place you should be addressing is what the turntable sits on. Airborne vibrations are going to be vibrating that and it will be transfered to the table. I once knew someone that was so concerned to eliminate vibration that he ran a concrete pillar up from his basement through the living room floor for his table to sit on but I have never heard of anyone putting a turntable in a box. My opinion would be that you gone about two miles down the HIFI Highway in the wrong lane. BUT, you might be on to something. You may be a Mad Genius and be on to something everyone else has missed. Just out of curiosity , your friend's name isn't Igor, is it.
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My turntable sits on a vibration control system from Newport Corp designed for electron microscopes and the like.

Setting a turntable on a concrete pillar is of limited value. One needs to decouple from the earth, not attach to it.

This is a quote from Jonathan Carr which can be found on Audiogon,

"The sound of the turntable is too much affected by vibrations transmitted through the air and ground. For top performance the turntable should be in a separate room/closet isolated from the vibrations and air pressure from the loudspeakers."

Advanced setups that I know of have the turntable in a separate room, which is the ideal solution.

Otherwise, thanks for your help.
Hey lets not give this Audiogoner all this flak for starting a tread that some find funny. I for one think many of the tweaks that some companies push as science are far worse in there appilication than this idea of a seperate turntable room without building an addition on to your real home, just might catch on. I would not be suprised if some company comes out with such a tweak and many of you will hoist praise and hossana in the highest.He who laughs last laughs the loudest do you hear that George.
George said, "Setting a turntable on a concrete pillar is of limited value. One needs to decouple from the earth, not attach to it."

Mine is decoupled, to another planet, the only problem now is the length of the cables.

Bob
George, I suggest you read the forum by clicking on the following link http://www.avguide.com/forums/turntable-isolation-platform
And if you wish to delve further then http://www.avguide.com/forums/sound-transmission
The views of Jonathan Carr, whilst being a solution to the problems, are extreme.Your interpretation of his views are bizarre and will solve none of the issues whilst introducing their own problems.