There may be better drivers out there but I think you will find that the 2 Pi's are excellent! I don't think there are any loudspeakers available that combine the virtues of the 2's: Inexpensive, relatively full range, fairly efficient, great performance with tubes or SS, and lively dynamics. You'd swear you are listening to much larger and more expensive speakers! Most other loudspeakers, DIY or otherwise have some of these attributes but not all. Some will be fullrange but not efficient. others will play nicely with tubes but have weak bass or poor dynamics... and the price can't be beat at all!

G.