Recommended headspeed of Trex 700X (12S Setup) for your reference.

1. Beginner hovering with max flight time: 1700 to 1750

2. Hovering and moving around (and slow 3D): 1800 to 1850

3. Smooth 3D: 1900 to 2050 (2050 is ideal)

4. Hard 3D: 2100 to 2150

5. Smack and get max noise (min. heli life): 2200 to 2300