Yes he used to make a socked one and now he makes only wood ones. The original one was a ceramic coated tweeter. Now he used the carbon fiber technology he gathered from the Model 7 mark 2. I think the tweeter is the same one that's in the 5, but I'm not 100% on that. Regardless the newer Quatro is something very very special in audio.
I need to listen to it a bit more, but I am currently listenting to my Treo's with an Ayre AX7e as the dealer has borrowed my new Ayre AX5/20 and the sound is natural and the stage is very large. The past hour has been a variety of classical and rock, lol. All hi rez recordings. Yesterday I was listening to my AX5/20 with Wilson Alexandria's and the sound was outstanding as it should be for 50K speaker. That said I still like the Vandy 7's over the Wilsons.
Different approaches and both work very well, but the Vandy to me is a more believable speaker. When you run the his newest speakers with the best electronics you get what you paid for. That said, this AX7e (the newest model) just sounds right, espeically for the price. I think it's a bargin in high end audio. I hate to sell this one, but with the AX5 here it's playing in the majors and it's not even broken in yet.
I also like the fact that I'll be able to use the crossovers with my integrated based on what I was told.
Are you looking to purchase the Quatro or 5aCT's new or used?