I also study flute, and your statement is inaccurate-"Qu Di in G". Only when you say that you play the flute in G key or Qu Di in G key, usually you say big G or small G, people will understand.
If you really use a small G, I personally think the sound is a little too high, and the big G is too low. If you use D or C, Qu Di's, it should be enough to play, and the barrel sound is 2.