Mods for Avantgarde speakers

It is very interesting.
i should try this myself.
in terms of support, I've experimented with various combinations, and found, that my current combination to be the best.
I have Stillpoints Ultra 5s in place of the OEM spikes ( had to make custom adaptors to screw Ultras in), speakers sit on Symposium platforms with some ebony wood plates (about 1/4" thick) in between the Ultras and Symposium.

For what it's worth...

My Uno's (2.0) are on Audioplan Antispikes and I plan to alter things like this: subwoofers on sorbothane blobs (I have a wooden floor, placed on a concreet base with felt in inbetween). This will stop the transfer of vibration into the floor. Under the supports for the tweeter/midrange, you van put spikes and such as they are blessed with threaded holes. By loosening the screws between the supports for the tweeter/midrange and the subwoofer, there will be some de-coupling.

Added bonus in my view is the fact that it makes leveling of the tweeter/midrange easier as there will be three points to adjust iso four. Placing the speaker exactly upright with precise tilt is extremely important in my view.

Last but not least: someone once told me that the subwoofers themselves are not that well damped. Looking inside you see that there is one sheet of damping foam present. This person had done some experimenting and suggested to put the damping foam in the back of the enclosure and to fill the enclosure with "Angel hair". This will lower the Qts and will lower the resonance frequency somewhat.

My 0,02 euro...

Hi,
If you have older version of Uno or Duo(before G2) it's very easy to time align horns without any modification. Just turn the tweeter horn around(180 degrees) and push it back about 20 cm. Use two(left and right) front holes and screw it on the stands.  To do this you need some books(you can remove them later) to support the horn and help of a friend(never do it alone) Of course be very careful.
I can provide pics if someone is interested.