Well, it LOOKS like crap...


I've been having some difficulty getting my turntable properly set up in my new house - I posted about this months ago, got some good ideas, none of which worked or were practical for my situation. To recap the basic problem, I had a Roksan Xerxes on a wall mounted shelf. The wall is an outside basement wall. The shelf is screwed into the studs, but I don't think the studs are tightly secured to the concrete, and the wall seems to resonate a great deal.

I finally decided to give up and put the turntable on the floor (concrete covered by carpet). This resulted in a nice improvement in sound quality, though there still seemed to be an edge to the sound. I started looking at floor mounted stands and ran across reviews for the Vibraplane. In searching for more info I wound up on some website that was talking about the resonant frequencies of tennis balls. TENNIS BALLS???

Now the vibraplane looks very cool, but the entry level price of $2K gives one pause. However, I can certainly afford $10 for a bunch of tennis balls, so I started rumaging around in my basement for something to contain a whack of tennis balls. I already knew how the rest of the thing would work:

I would stick some extra spikes on the bottom of the three pieces of 18"x15"x1" MDF that I had glued together in hopes of making a less resonant shelf for my wall mounted turntable stand (a dismal failure). I would sit that structure on top of another 18"x15"x1" piece of MDF, which in turn would be sitting on top of a bunch of tennis balls. The only thing I could find was the top of a plastic storge bin that had raised edges inside that would properly contain twenty tennis balls.

So, a trip to the dollar store and $7 dollars (CDN!!!) later, I arrive home with twenty tennis balls. The balls go into the plastic lid (it sits upside down of the floor), and the first piece of MDF gets laid on top of the tennis balls. Damned if the stupid thing doesn't roll back and forth, and side to side by about half an inch each way. THIS WILL NOT DO!!! I am almost stumped, when I spot an unused U-Haul box left over from my move last year. The box gets cut into pieces, four pieces get folded in half, and stuffed into the space between the edge of the lid and the sides of the MDF. Not only is the MDF sitting snugly, but I burst with pride from having invented the first audiophile cardboard.

Well, the 3" thick slab of MDF (with spikes no less!) goes on the single sheet of MDF, which is jammed into place with audiophile cardboard sitting on tennis balls inside the lid of a plastic storage bin lying upside down on the carpet of the floor of my room (there's a flea on the hair of the nose of the frog....), and the turntable complete with it's own proprietary 6" stand sits on top of this highly complex and technically sophisticated structure - the platter of the turntable itself is now about 18" off the floor. Out comes the level, and....it's not even close.

Now I didn't feel like messing around with the screws on the Roksan stand - they were level when the thing was on it's wall stand, and they were level with it on the floor, and of course I'm figuring that's where the stupid turntable is going to wind up being within about 15 minutes - so out come two more pieces of audiophile cardboard folded in half to act as shims to level up the table. Not perfect, but close enough to call it a day.

As I wander to the LPs I giggle maniacly, because this thing looks so damned stupid, and I've wasted a good hour running around buying cheapo tennis balls, sticking old spikes on MDF, and tearing apart perfectly good cardboard boxes. Anyway, on goes Donald Fagan's "The Nightfly", and.......

HOLY CRAP DOES THIS SOUND GOOD!!!!!!!!!!!!!!!!!!!

Better timbre, lovely warm and rounded mids - particularly vocals - punchy, tight, deep bass, better imaging and depth; you name it, it was better. It was not just a little better, it was holy s*** better! I've been spinning records like a banshee all afternoon, and they are all better! Way, way, better.

My fear is simply this - this "isolation unit" cannot stay this way, I will have to build a more permanent solution before my audiophile cardboard starts to flatten. does anyone have any opinion how this project might be better finished? I was thinking of making a shallow box out of MDF, putting spikes in the bottom, inserting the layer of tennis balls then putting the single layer of MDF on that. I would try to make the piece of MDF slighly smaller (1/4 or 1/8 inch) than the length and width of the box so that there would be a small gap between the edges of the box and the edge of the single shelf. I was then thinking of sealing the crack with silicon to keep the shelf motionless. Or should I use precision cut audiophile cardboard?

Any thoughts? Anyone? Bueller?
esoxhntr
If you put a litte dab of caulk or whatever on the top and bottom of some of the tennis balls they would stick to the shelves and not roll around. Or cut them so they have a flat side. Or drive nails through the shelf so they stick up an inch or so and push the tennis balls down onto the nails. Or find some rings like napkin rings that the balls can sit on to keep them from rolling. Or drill inch or so holes in the board so they sit down in the holes. Or glue 3 or 4 together where they touch on the sides.

Can't you level it by adjusting how far you screw the spikes in? That sounds like a better long term solution than wedges of cardboard.

You can build a wodden skirt that hangs from the top board that is just slightly shorter than the balls so they will be hidden.
Herman:

I could level it with the spikes IF they were glued in, but they are just stuck on the bottom with two-sided tape for the moment. I will be installing spike on the bottom, I could use some suggestions as to whether I should use 3 spikes or 4.

I like the napkin rings idea - evenly cut slices of 2" PVC pipe should do the job, and they would be easy to glue or silicon to the surface of the MDF under the tennis balls.

Thanks,

George
A friend made a homemade MDF sandbox for my roxan that I used for several years. I've used inner tubes, squash balls superballs cut in half with cork, yes, tennis balls but the most effective for me are the Gingko mini clouds under the roxan. However it all comes down to what you hear in your application. The roxan is very sensative to whatever it sits on. Glad it works. Enjoy.
Before you go making something more permanent, I would suggest trying something other than MDF. An easy experiment would be birch plywood. Maybe not all of the MDF, just the one in contact with the TT. You might just grab a small end table from the family room and try an experiment siting the table on that.

I once moved a table from a 1" thick MDF tv stand to an old sewing machine cabinet made from 3/4" maple. The difference was amazing. Better details and the bass tightened up and got punchier. FWIW, YMMV.
Tennis balls go "dead" a few weeks(or less) after you remove them from the can. Expect things to change with time.

Regarding the "spikes", 3 points generally don't require leveling, while 4 points may require it.
Food for thought guys, thanks! Dan ed - I actually tried a couple of short and reasonably sturdy tables (one of them was a 100 year old school desk)with somewhat indifferent results. I will however try a couple of different platform materials to see what happens. TWL - I was wondering what the life of the tennis balls would be, but I was also thinking that if they lost a little compression that might not be a bad thing in terms of their vibration absorption capabilities. Good point about the lack of levelling issues with 3 spikes. Bluenose, I'll look into the mini clouds, what have you got them sitting on?

I am not entirely sure how much effort/expense to put into this - I am still considering a turntable change/upgrade (my Roksan's plinth is about 1mm from disaster), but I figure whatever I earn from this, I can apply to the prospective new table, especially if it is an unsuspended type such as a Teres, or SME 10.

Keep 'em coming!
You seem to be gradually converging on a home-made version of Gingko Audio's Cloud 11 platform/isolation product. Gingko has rubber balls captured between two boards, with appropriate dimples and rims to keep everything in place. Of course, your version will be much less expensive than buying his. Go for it!
I have the miniclouds under the roxan on top of a target 5 shelf stand. The top shelf has spikes under it and the stand sits on four large superball halves, flat side down. The table "floats" as the ginko blue balls have a bit of roll in the acrilic bases, but I don't have trouble with bounce. Now if you live in Canada and have a home hardware near you you could try the Lanard Total X-Stream air balls for cosmic thruster air guns. The number on the package is 91040, contains 6 yellow air balls and sell for $4.59CDn in the toy section of your home hardware. These are very effective under cd, pre, even speakers if you sit them in something like vibrapods so your system doesn't try to roll away. No, I haven't tried them in place of the minicloud balls yet......I do believe you'll find them 'better' than tennis balls....cheers,
I was recently at a business conference and one of the presenters handed out these squishy "worry balls" to attendees. It's the type of thing you are supposed to squeeze to relieve tension but it has some real interesting properties. If you throw it hard against a wall or floor, it doesn't bounce, it just drops dead. This suggests some very interesting energy absorbing characteristics. The material is also not unlike that used in the wrist pads I have seen for use with a mouse or computer keyboard. I haven't tried the "worry balls" yet under my TT but I grabbed a few extra and I intend to. There are all kinds of interesting materials out there to try for free!
Bluenose - I am very close to a Home Hardware and will check out the X - stream balls, though at nearly 90 cents a pop they are getting a bit pricey :) Also, check out my system and see if we are using the same Target stand; I think it's very possible.

To all: Phase two of the project begins tomorrow! I have some audiophile ABS plumbing adapters arriving at the local audiophile lumber store. Once I get them, them I can install the audiophile bigass wood screws (really huge lagbolts more like...) and start gluing and screwing! I will be freed from the shame of using a storage bin lid and cardboard shims, and bask in the prestige of one who has wielded a power tool in search of audio perfection! I will have constructed a solid and structurally complex piece of audio furniture that will no doubt be hailed as a master stroke of design! I will be forever renowned as a true genius!!!

I also bet $20 that it will sound better just as it is with the plastic lid and cardboard shims. Sigh...
George,the X-balls are sometimes on sale. I got my first for something like $3.98 a pak. Yes, I believe we have the same target stand. I also have a target turntable stand but the tv sits on it so I can play dvd-music videos and movies through the system. Most listening is music only though. I did have the plinth on the roxan adjusted. This is the only flaw I've experienced with this unit. You have a seriously fine system, much 'bigger' and I'm sure superior to my own modest and aging setup. But it does do music, thanks largely to the newform research nr-8-2's. Let us know how the project sounds. A friend of mine made a beautiful stand for his system using mdf. Alas, he and his wife found, the system sounded 'worse' on the new stand...I guess mdf has its own properties, everything 'sounds'. Good luck and good listening. Your system will reveal every 'tweak' you try, good or bad or different.....lloyd