what speakers do the best "disappearing act"??

I agree with Redkiwi. You need to find help in setting up your system. I can only add that analog (records) do it better than digital.

yes the avalons are very good . try jm lab . sound labs with tubes are scary. that is what you are looking for i think. tim why dont you go hear the labs with good tubes?

I have a pair of Sonus Faber Extremas and are as transparent as they come. I know I will get told I am nuts for this but properly set up they will actually image behind you at times.

The older Totems (Sttaf, Arros), the Reference 3A DeCapos and some of the British speakers like ATCs and Spendors. Good luck

Every speaker I have had for the last 15 years or so has achieved what you want. The trick is mainly in room treatment and speaker positioning.

Sounds like you have described Avalon Acoustics with out hearing them. They are known to disappear, even some stereophile reviewers admit this in there reviews which I seldom here them say. But more important then speakers is room placement which truely makes speakers disappear. I would say get the best avalon's you can afford and don't look back, those of us that have them don't and we always go back and buy new ones(when it is time to upgrade of course). It is very seldom if ever that anything bad is said about avalon except the fact that some folks want them and don't have them. Good luck I am sure others will give you suggestion, so now you gotta go out and listen to everything. Regards, Tim the Tire Guy