Racquetball isolation platform perfection

Stanwal : Thanks for your input. I'm a little leery of using anything heavier for my platform material. Here's why: I have some lead weight bags from a dive shop, and tried weighting down the source sitting on the racquetball platform I made. No amount of weight I tried improved anything, but it did take away dynamics and make the bass more bloated. It may just be that my system found that lucky " perfect spot " exactly as I have it, or it could be that the birch plywood is acting as a constrained layer shelf itself and killing some of the vibrations before they get to the racquetballs. Ginko themselves use a lightweight plexi material.
I will however buy a few more racquetballs and make some small slices in them to see exactly how that works. At that point though, there are no more air bladders, just absorbtive material. I'll report back..

I made something similar under my turntable. Basically my TT sits on a butcher block, then I put 9 squash balls under that, then there's another butcher block floating in a sand box. I didn't route out any cups for them though.

Try the squash balls instead of racquetballs. They flatten down quite a bit more and do not bounce (squash balls are essentially dead). Here's a picture where you can sort of make them out:

http://cgim.audiogon.com/i/vs/i/f/1231696007.jpg

Here's a link to the balls I used:
http://www.amazon.com/Prince-Squash-Single-Double-Yellow/dp/B001H0G1AA/ref=sr_1_43?ie=UTF8&s=sporting-goods&qid=1232559985&sr=1-43

Enjoy,
Bob

Hi Bob,
I considered using different balls, but after doing some research online, I found where a university science and engineering class did a research study on the properties of racquetballs. While this covered literally EVERY property imagineable, it was especially interesting when they studied what happens when a racquetball compresses or bounces. They found, and proved with some sort of seismic looking computer readouts, that the bouncing or compressing is converted almost entirely to heat ..... This is exactly what you want any isolation or coupling system to do ... Convert energy to a non interfering form of energy. This is probably why Gingko has such success with their products. I've tried several different isolation materials ( wood, lead, ect ) and all of them killed my system's dynamics and inner detail.
Just some food for thought.

I was thinking of doing the same thing but was thinking hand balls or squash balls since they are much denser than raquetballs. I was thinking of getting a slap of plexiglass (like gingko uses) and using a hole saw to cut the holes so that the balls would sit stationary. I am glad someone else has tried this and it works. nice

good discussion guys & perfect timing for me! :-) I am in the midst of making a tweak to my TT isolation platform! I've had a sandbox with a "floating" top-plate under TT for the last many yrs but recently felt (after reading some threads on another forum) that I could do even better.
I'm now thinking of isolating the rack shelf from the rack using 3 brass cones. Then, isolating the sandbox from the shelf using another set of 3 brass cones & finally isolating the "floating" top-plate from the sand in the sandbox using large bubbles bubble-wrap.
What do you guys think??

I was also thinking of racquetballs & squashballs - I felt that the racquetballs would be too bouncy hence might not be effective in damping but I'm happy to read from Timtim that they convert all kinetic energy to heat. Timtim, can you please provide the link to that article? thanx!

04-21-09: Emorrisiv
I was thinking of doing the same thing but was thinking hand balls or squash balls since they are much denser than raquetballs.

I *think* that in this case denser would be worse, no? The denser the material, the higher the coupling & the worse the isolation. Racquetballs might be better as they are more full of air - less coupling??