Sandbox TT isolation pictures, please.

Spectrum77 said:

SaSi- very informative. I'm in Japan, and quite often I cannot obtain specific products; in this case I have never seen anything like 'play sand' but can envisage the two different size grains. So, has anyone heard of random-sized sand, such as sieved beach sand being used? Would it compact too much, defeating the intended effect of the liquid nature of the sand?

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We got more sand than I know what to with down here!

Sasi wrote:

<IMHO, the best performance sandbox won't have a top cover. If you won't accept having your TT laying in the sand, then 4 circular legs (brass or steel preferably) can form a "civilized" base on top of the sand.>

i know that some Thorens' owners have replaced the bottom board of their TD-125 with a thicker piece of plywood, but one with a big hole cut out in the middle, presumably to the same effect. Why not do the same with the top board of a sandbox? That way you could have the best of both worlds.
Why leave the top free? Because the free face of the sand in the air allows it to vibrate freely and release more energy in the air, rather on the TT.

Crikey! I thought this was going to be an easy-peasy-Japaneasy, "no-brainer" kinda project. Nope. Not with some science driving the design it won't be- SaSi, again, food for thought. I understand the reason for using sand vs a solid mass such as stone now. Thanks.

sabocat said:

Sasi wrote:

<IMHO, the best performance sandbox won't have a top cover. If you won't accept having your TT laying in the sand, then 4 circular legs (brass or steel preferably) can form a "civilized" base on top of the sand.>

i know that some Thorens' owners have replaced the bottom board of their TD-125 with a thicker piece of plywood, but one with a big hole cut out in the middle, presumably to the same effect. Why not do the same with the top board of a sandbox? That way you could have the best of both worlds.
Why leave the top free? Because the free face of the sand in the air allows it to vibrate freely and release more energy in the air, rather on the TT.

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Haven't used one before but contemplating it when I finish restoring my Thorens. Sabocat's suggestion makes more sense to me intuitively. I'd think that going just with small feet as contact points may make the TT inclined to settle in the media as it absorbs the vibrations - and I'd think it would fall out of level very easily. Some sort of platform, or larger foot, to widen the point of contact would reduce this effect wouldn't it? I'd think there's a point where a broader contact point would reduce/eliminate settling while still performing better than the whole platform which may be inclined to transmit more movement.

When you know the "science" of a subject, then the design is pretty simple and, boring, I dare say.

The "scientific" approach when you don't know what to do, is triy, measure, re-iterate. And that is part of the fun. At least, it is not expensive to do some experiments.

Using a frame as a top cover, with a width of 3-5" leaving the center open is really the best of both worlds, as externally looking at it, it appears as a rigid and closed plinth.

But the top cover should never make contact with the surrounding frame. Otherwise, vibrations from the base coming up from the side panels will reach the TT base and all the sand goes to waste.

I would also try mounting the TT on four inverted spikes hammered in the sand mass. I have no clue if it improves or not the total effect, but if one has 4 spikes from loudspeaker mounts, I guess it's worthwhile to try that.

The open sandbox might damp vibrations more effectively, however, my concerns are

1) maintaining level. Some TTs may be fairly even on weight distribution but many have much more weight on one side than another. I would think that over time the TT would sink into the sand...and not level. It would take fairly broad feet to stop the uneven settling of some of the heavy TTs out there. Light TT..maybe broad feet to float on top.

2) Sand getting around...possibly into bearing assemblies. I'm sure that if it were never disturbed that wouldn't happen but it's like anything else - accidents happen. Once it happens, sand can be very difficult to completely remove...at least without disassembly.

I installed my sand box today. It matches the oak speaker caps that I also painted black. The actual box weighs @ 15-20 lbs and I added 50lbs of play sand from Home Depot. I have only spun 1 LP but it was one that I have listened to quite a bit and I definitely noticed more weight to the music and heard some bass that I have never heard before. I have not received the 18" x 18" piece of black galaxy granite yet so I am using the same piece of slate that I have been using.

So far positive application to my system.

Thank you Sir, for the most excellent photos. I'm glad for you that you could perceive an audible improvement for your effort. Looks great, too. What determined the distance between the sides of the box and the TT platform for you? I have been planning on a design requiring a gap of no more than 10mm. Also, how did you go levelling the sand? I was thinking of using a short builder's spirit level.

I determined the size of the box by the size of the tile I was going to put in it. 18" tile, 19" interior dimension of the box. 1/2" all the way around. I used a "Torpedo" level which is about 7" long on the flat. Worked fine for me. I used it like a screed.

I just bought a digital camera and thought I'd put up a couple pics of the sandbox I built last week.
I thought it would be cool to make one that met the body lines of my Pioneer PL-550. The sides are 1/4 inch MDF and the bottom is 3/4. I cut the corners on a 45 so they'd be neat. It was fussy-making filling it with just the right amount of sand to get the 1/8" gap, but it was satisfying and has improved the sound of the TT. Here it is. I may post more on it later.

Brett a said:

I just bought a digital camera and thought I'd put up a couple pics of the sandbox I built last week.
I thought it would be cool to make one that met the body lines of my Pioneer PL-550. The sides are 1/4 inch MDF and the bottom is 3/4. I cut the corners on a 45 so they'd be neat. It was fussy-making filling it with just the right amount of sand to get the 1/8" gap, but it was satisfying and has improved the sound of the TT. Here it is. I may like post more on it later.

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Looks great!! Well done :thmbsp:.

Nice job!

Brett- I looked at the photos of your living room set up and the TT isolation certainly came a long way very quickly! Looks very pro and sets off a beautiful turntable, too.

Thank you for the kind words.

A few things I took into account which you may or may not find interesting:

I had to make the side walls thin (1/4 MDF) to allow space around the TT feet and still have the outside dimensions line up with the plinth. I also had to notch the back panel to allow the cables to exit unobstructed (see photo of rear)

I resisted buying sand on principal for a while, but finally broke down and purchased some play sand at HD. It was quite damp in the bag, so I dried it out in the oven on cookie sheets for 20 minutes at 400 degrees. This worked well.

I then realized the play sand was dusty as all get-out; when I poured it from the baking sheets into a bucket, it sent up a plume of dust that rose across the yard like smoke. I didn't want that dust residing so near my equipment, so I poured the sand back and forth between two buckets holding the mother bucket high and letting the fine dust blow away with the breeze as it fell while the heavier grains fell straight into the other bucket. (This is how they used to thresh wheat, sort of)

I ended up adding some fine silica sand to the mix also (I had a bag of this around already) so I achieved a bed of sand of varying gain sizes which I believe will do the best job of staying 'liquid' over time (not settling into a solid mass)

I smoothed it out with a make-shift device that rode along the top edges of the box and leveled the sand at just the right hight to accommodate the sub-chassis of the TT. I should have waited longer than 24 hours to do this because when the removed the blue painter's tape I used to protect the finish on the top edges, it lifted the paint right off the primer. (I touched it up today and took these naked outdoor photos.)

When I put it back together today, I used a piece of Celotex Sound Stop for the load panel. I figure since what I really want to do with this sandbox is drain vibration away from the machine itself, whatever the TT is sitting on should move easily, transferring the energy into the sand with the least amount of resistance. I think though that the 1/4 inch MDF I used for the first few days worked better than the Celotex.

For less than $20 and about six hours of fun/labor, the box has made the TT quieter which is what I wanted. It seems to do nothing for foot-falls however, so I think I'll try some racquetballs cut in half under the box instead of the 3 spikes I am currently using. (And put a floor jack under it in the basement, but that's a separate project.)

Well, thanks again for the kind words. It's been fun and satisfying (and effective to boot!):yes:

So, it's about seven months since I built the sandbox in the last post in this thread.
I just got a new 'table, a Rega Planar 2, so it was time to build another. Here's the before:


and after:


I built this sandbox last week. Tonight before I left work, I quickly put together an adjustable sand leveler thingamabobber.



I take a minimalist approach to the load panel(s). I figure an important function of a sandbox is to drain vibration away from the machine. For this, the lightest panels work best. These are three aluminum panels I bought at HD. (package of 8 for $3). I bent the corners down so they'd get a little bite into the sand.

The holes in the back wall are for the power and signal cables.



I thought the Rega would look best with its plinth set in as box top.






I wanted to carry the corner detail from my Shanling amp to the sandbox---kind of a recessed quarter-round thing. (You can see the corner of the aluminum amp in some of these pictures). Eventually, I will work on this detail a bit more perhaps with contrasting semi-flat black paint and faux seams.

Anyway, I'm pretty pleased with the way it came out. I'm convinced that a sandbox isolation stand is an essential accessory for anyone who uses their 'table for critical listening.

Thanks for looking
:thmbsp:

Nice work Brett a. I have made lots of sandboxes and feel they are good for suspension-less tables. I have also had success with a couple CDP's as well, but not all. Rega's are light and thinner sounding so a sandbox is a good choice. It is however not a bigger is better thing, meaning they don't sound better the bigger the sandbox is. And I have tried every kind of sand known and can't say it makes a difference.

IMO a well suspended table is still better and a suspended table on a Target wall mount or the Sound Organisation TT stand that I have is far better. That said, I have my P25 on a sandbox that I made to match it. My Yamaha PF800 TT however crushes it no matter what it's sitting on.





marc mc

Brett, How did you "drop" the TT into the box without "dropping" it in ?

speedracer said:

Brett, How did you "drop" the TT into the box without "dropping" it in ?

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The short of it is that i can stick a finger in through the hole cut for the AC cable to raise or lower the 'table in and out of the box.

Well done Brett, very nice work.:thmbsp:

Brett, your Rega looks phenomenal in that sandbox. What kind of differences do you notice? Also, any concern with sand getting into the bearing? Lastly, what did you use as feet under the box?