3 duduks in A, C and D - "Dle Yaman" HD

I played "Dle Yaman" subsequently on 3 duduks in the same conditions to compare sounds. Duduk A and C are from Arthur Grigoryan, duduk D and all reeds are from Gevorg Dabaghyan. It was recorded on Olympus LS-5 and was not processed in any way to show real sound of duduk. The high instruments in key C and D are very sensitive and it is not easy to keep it in tune on higher notes. The duduk D has very high backpressure and sometimes lost sound when I blew it to weakly at ends of notes.