I would first make certain that the legs of your rack are sitting on top of your floor joists opposed to on the plywood between the joists. This will give you the most stability. You don't want to use anything that isn't rigid under the table. I use granite but it's not really inexpensive. You might want to try a large paver block 18" x 18" or something in that nature.
Not sure how cheap is what you consider as cheap but ...
As a turntable platform, I use two 24"x25"x1.5" maple counter tops laid flat on top of each other, separated by a cork sheet (1/16" I think), placed on Mapleshade brass cones.
It looks nice and really does wonders for isolation.
Look into suspending the turntable from the ceiling. That solves footfall problems and is effectively better than the 'self on the wall solution'.
The bouncing is the result of vertical displacement from the movement of the floor. This will occur without regard to the type of isolation you use so long as the TT is supported on your floor unless your floor is braced to avoid flexing. Suspended TT's are especially vunerable to this type of movement, thats why folks recommend wall mounting. Interestingly unsuspended tables can often work reasonable well over such a floor. You could try using a large rigid platform under your stand insuring that the edges of the platform overlaped the floor joists. That might help but it might look quite ugly depending of the width of the joists and composition of the platform.
Most isolation devises are designed to deal with small vibrations. The vertical displacement is not really a 'vibration' that they are designed to deal with. If you can not eliminate the vertical displacement then the only thing that makes sense to me is to use something soft under the table like an air bladder based support.
Relating to the VPI Table, I'm wondering if you have the spring suspension on it, as you might be better off with the Sorbothane Pucks instead. Audiopoints replacing the VPI Rubber feet will help a bit, but these aren't cheap for a set of four. I bought some a couple of months ago for mine, and they seemed to help a bit, made the table look a lot nicer too, but one will get of sticker shock for the four 10-32 Points, and four coupling discs.
Another downside of the VPI, is its odd size footprint, making it harder to find readily available stone slabs, or wood bases.
An option I've thought of for myself as an inexpensive project, would be a DIY Sandbase (ala Brightstar) but I haven't done mine yet. Small 2'x4' Sheets of 3/4" MDF are available from places like Home Depot Home Supply, the Borders-Sides could be also made with 3/4" Oak, giving a nice look, and the Top Plinth of the Base could be sprayed with a nice texture-spatter paint to compliment the rest of the Base.
Even if you don't have a good saw, Places like Home Depot can do all the cuts needed for a very small fee, and all you'd have to do, is button everything up, fill the base with sand so that the Plinth sits level to the top of base, leaving 1/2" gap all the way around the base Plinth, and fill this void area with 1/2" Strips of Black Foam Weatherstripping for the finishing touch.
With all MDF, the cost probably wouldn't exceed $20 in parts. With 4" high Oak Sides, naturally will cost more. A base large enough for the VPI would no doubt be still suitable for many other turntables as well. Mark
You wouldn't need any isolation if you had a set up LIKE MINE
Make sure your volume is on
Dave, you are crazy! That's the funniest thing I've seen in a long time! I was LOL!
My turntable is on a built-in shelf that is OK but footfalls could be heard. Short of tying the kids up in the attic whenever I wanted to listen to music, I went to a local shop that installs granite kitchen countertops. After wading through their scrap yard, I picked up two slabs about 1.5" thick and had them trimmed to 18x22". They essentially gave away the scrap and only charged me for trimming and polishing (about $50 if I recall correctly). They look great and really do help to isolate the table.
I don't know why people continue to have problems with TT vibration. Mine went almost completely away about thirty years ago when I got an Empire TT which had two features of interest. (1) The platter and the arm moved together on soft springs. (2) The arm was mass-balanced around all axes, with VTF applied by a clock balance wheel spring.
I would expect that more modern and expensive TT would be better than the old Empire.
Now I have a Sony PS-X800 TT which has a linear tracking biotracer (servo'd) arm, and it also shrugs off vibration, and plays even badly warped LPs without any problem.
Have had this experience with my Ariston 11-S, (like an old Linn) after I removed it from the wall. The other folks who responded are correct. It's the Floor. I put the TT on top of the Target turntable shelf,6 vibropods in the middle, and a black flakeboard shelf on the bottom. This vibropod sandwich rests on my stand. Results were good. I like the Granite Idea. Also, I installed 2 lollycolumms under the 40yr old woodfloor which really helped. Walking softly right in front of the stand also helps.
Markd51's comment about replacing the VPI's spring suspension with the Sorbothane pucks is well worth considering. I have a VPI HW-19 Mk4, and had lots of problems with "turntable bounce" due to the suspended flooring in my home. I tried lots of different isolation approaches, but finally found the solution when I installed the Sorbothane pucks. If you decide to install the pucks (and maybe the cones used with the VPI Scout, which I found to be a good addition), you will need to do some minor modification of the turntable's base. Drop me a private note if you'd like more info.
I have decided to build a sand box isolation base. I am starting on it tonight & will let everyone know how it works out.
OK, I am staining tonight & this will be finished. This is what I did. The base is 16" X 21" plus 1" thick sides mounted on the outside of the base.
I cut 3/4 MDF for the base & top. I cut the top 1/2" smaller than the bottom. I used poplar 1 X 4" for the sides & nailed them to the MDF base in addition to using some liquid nails. I used 45 degree miter cut's on the corners to look a little pretty. I filled all the nail holes in with some putty & sanded. I am staining the base & I painted the top cover black. I will coat everything with polly & fill the base with a 50 lb bag of playground sand I purchased from HD. I also purchased some simple & cheap rubber feet for the base but do not know yet if I will install them, I may end up trying some iso nodes instead. All told it cost me about $40.00 for the materials but I already had some scrap 3/4 MDF lying around.
I plan on installing some cheapo adjustable iso points feet that I purchased from parts-express under the turntable & placing on the top MDF cover that I built. I don't have alot of money into this & if nothing else it has proved to be a fun project. I will set everything up this weekend & see how it sounds.
I made a very simple stand out of 5 pieces of 1" thick MDF, 20 pieces of 2" ABS flanged caps, glue, and 20 cheap inflated rubber balls from the dollar store. Just over a year later, my SME 20/2A and I are still very satisfied.
One extra thing you might try. This is something that was recommended to me since I also use sandboxes (see my system pictures). That is to make a few pieces of MDF or some of the poplar into strips, maybe 1 inch or 1 1/2 inch in width and glue them on edge to the bottom of the top shelf. This way they protrude down into the sand and act like sinks. Picture it like an upside-down heat sink. I'm in the middle of a couple of other projects so I haven't gotten around to trying it yet. It does make sense though.
Best of luck,
I have no problems with isolation from footfall with my set up. I have a 5 foot tall Zoethecus rack sitting on a suspended wood floor. But, the rack is actually fixed to a nearby wall using angle brackets attached to a cleat that is, in turn attached to the wall. My table is a Basis Debut.
I generally find that lighter tables with spring suspensions to be the most susceptible to problems with footfall. Big heavy tables that have damped spring suspensions work the best. It is analogous to big heavy cars riding over bumps in the road.
For your temporary set up, I would think that the easiest, and cheapest experiment at isolation would be sorbothane pucks. They do a very good job of dissipating the energy from the movement of the floor without itself oscillating.
I found that the energy causing my problem were horizontal rather than vertical. The equipment stand actually rocked very slightly with the flexing of the floor. If that is your problem, you may be seeking stability rather than isolation. That is where the wall cleat might come in handy. Or the wall mount.
My Linn deck rests on a 3/4" slab of slate of the same footprint. The slate sits on three ball-in-cup feet and the whole stack rests on a 6' side table located along a wall. The three mushy feet allow for damped vertical and lateral movement. The slate, about the same weight as the deck, worked better that just supporting the deck alone on the feet. Sending the kids to a friend's house works even better.
Like you, I built a sand box with a floating lid to go under the TT. If you are setting the box on a shelf or other flat surface, I suggest you elevate each corner in order to minimize the box from absorbing any shelf resonances. A simple solution is to drive a small brass screw up into each corner of the box from underneath. Leave the entire head showing, and it will act as a small spike.
My sandbox didn't isolate as much as I would like. It was a fun project but I still have the skipping problem. Short of hanging the TT from a wall shelf what can I do?
I was afraid of that. The problem is the sandbox is great for vibrations but, obviously, it is bouncing with the floor as well. As others have mentioned the real solution is to completely decouple from the movement of the floor. You could try moving to a wall or corner that has a load bearing structure beneath it in hope that the floor bounce won't be as severe in such a location. Otherwise, it's either the wall shelf or hanging it.
BTW your sandbox could still be of benefit on a shelf.
Don't give up!
You have two other solutions make the floor stop bouncing or get a turntable that is immune.
a. You seem to shy away from any type of structual reinforcemnt to your house. Heavily padded carpet might absorb some of your footfalls.
b. Most turntables today have no suspension at all. Those that do are not designed to deal with the magnitude of oscillations you decribe.
c. You need a turntable that floats the arm and table together. Even though your floor is bouncing the arm and platter "float" together and the cartridge remains in the groove. Sota and Linn make such tables.
Ultimately a major floor bounce is really an unacceptable situation for a turtable. For example a cd player has error correction and will continue to play even when it is mistracking. A turntable has no such correction. Even though it is still playing, it is still mistracking.
The only real solution is to stop the floor from bouncing or a wall mount.
I don't really know how to support the floor better. My room is located over my garage & I use the garage for storage of vehicles. I couldn't put a bunch of support collumns under the floor because it wouldn't allow me to park any vehicls inside.
At this point I would rather not put up a wall shelf but it seems to be my only option.
I am pleased I made the sand box, it was fun & came out great. I plan on using it under the turntable regardless so it wasn't a waste.
Fishwater, I have a listening room over the garage and have put in two simple ways to reduce the amplitude of floor vibrations. First, lag bolt 2X6s across the joists down the middle of the floor. Second, put a single post in the middle of the floor in between the two cars. If you put it forward of the front doors, it will not interfere with getting in and out. This combination will significantly raise any floor resonances and their magnitude.
Perhaps rather than hanging a shelf on the wall you could just attach the existing rack to the wall so that it cannot rock when the floor flexes. In my case, the motion that caused the problem seemed to be horizontal, not vertical.
As an update, I cut some raquet balls in half & installed them under the isolation platform. It certainly helped with the footfall issues but if the TT does get moving the balls keep it moving, the needle bounced almost half way across the record until it stopped. Under normal conditions of moving around in the room the raquet balls are a definite step in the right direction.
Build your own. I have an old AV clamp rack where inbetween I clamped two cinderblocks & some cut 2 X 4's to raise platform. Using spikes & cones, a level you can construct a wonderful turntable stand. I can actually jump up & down right next to my table while playing and does no skipping whatsoever. The clamp rack was by I believe Michael Green......Enjoy.