If you can figure out the new system you can convert your old AH2 sounds.
The new system is not the same as the old. I explained all of this in the video I made on how to make the conversions. The engines work on rpm, but tracks work on MPH. The new system has internal sounds, and then there are external sounds. The external sounds are one of the greatest features, in my opinion. What you hear externally can be made from airshow recordings, so you know the aircraft or tanks can have very characteristic sounds (recognizable).
The only problem is that it doesn't always work right. It has to be a bug of some sort, because the sounds in the game work fine. The way I approached things the tank tracks take the most time.
Anyway, even after the bugs are sorted out there is the possibility of sounds that never were in AH2, for instance the track sounds. In AH2 the tracks always sounded the same, but in AH3 they can change rates. MG sounds also are different, because you can add random pitch changes so that the MGs do not sound as mechanical, and regular. I am planning on getting some great recordings of the guns we have in the game, but that won't happen any time soon.
Anyway, three more weeks of school and I will be finished and then I can concentrate on more FMod work.