Mods for Avantgarde speakers

I have exactly the same speakers.
are you sure you can remove subs from the frame?
it might be a great idea

Yes, there are big knobs on the sides that you will see that have a screw going through to the frame and into the bass cabinet. Very easy to remove, just turn the big knobs counter clockwise. I put magazines under the speaker cabinet so that the screws would not bind from the weight of the cabinet as I unscrewed them. I am sitting here listening right now and can say that I have never heard better.

My next step is to find a way to spike the bass cabinets to the floor. The height needs to be 4" to clear the frame.
I looked at Mapleshade, but theirs are 3" for their large footers. I might need to add wood across the bottom underside of the bass cabinets, then the footers to that to get the 4 inches needed. I am thinking two brass footers in the rear and one in the middle front.

Another consideration is to have the front a little higher than the rear for better tweeter alignment.
Another benefit of this mod is that the bass vibrations from the cabinet cannot reach the midrange horn since the bass cabinet is no longer attached to the frame.

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.