Best Isolation Device for Speakers?

This thread is of great interest to me currently. I have recently placed my 5As on a piece of MDF over the carpet on a large second floor listening room over the garage. I did this to help me move them around for purposes of testing. What I discovered is that the speakers had much more life in them on the MDF. The highs were much clearer and the vocals more magical. After listening for a couple of weeks, I put them back on the carpet in exactly the same position and the life was sucked back out.
I had previously believed that the speakers were best off coupled to the floor, and the 5As have cones which I assumed were coupling devices. Now I realize that for reasons I can't explain, the image is much better with a degree of isolation.
Let me also say that the cones may not have penetrated the thick carpet and pad very successfully.
Can anyone help here? Should I be considering a better isolation platform under the speakers? Or should I be cutting through the carpet to let the cones get to the subfloor? Can an of the Systrum technology help? I looked at their stands and I don't think they can mate to the botton of the 5A with its sub opening and grill.
Thanks for any help.

You need to call the boys at Starsound about the use of Sistrum with your speakers..You should be able to position the triangle of the Sistrum in a way that will not interfere with the driver on the bottom..They will help a lot. Even the use of Audiopoints 1.5 in will be large..Tom

Isolation vs coupling...I won't go there. However, if you want to isolate, nothing is better than suspending the speakers from the ceiling. Chains or wire, and perhaps monofiliament fishing line works. For even better isolation (from the ceiling) you could use bungie cords. Cheap too.

With the boxes floating in space you get acoustic isolation as well as mechanical isolation. IMHO the acoustic part is usually most important.

Sir I beg to differ. In your proposal there is no provision for resonant energy to leave. The resonance will come out the front the back the sides. You will have a 360 degree resonant pattern to augment the music..Tom

Theaudiotweak...Enclosures should be solidly constructed of "dead" material, shaped so the panels don't vibrate, (cylinders are good), internally braced, and internally damped. If the top/sides of your enclosure vibrate, even glueing the bottom to a concrete floor wouldn't help.

Of course, the real answer is to get rid of the box entirely: go planar.