Often hoses, valves and tubes will prevent this. Quite often they can also interfere with micro - managing the individual notes on the chanter or the drone chanter balance whilst playing as well.
This synchronicity has been shown with metronomes when placed on a moveable surface. Energy from the motion of one ticking metronome can affect the motion of every metronome around it, while the motion of every other metronome affects the motion of our original metronome right back. All this inter-metronome "communication" is facilitated by the board, which serves as an energetic intermediary between all the metronomes that rest upon its surface. Similarly the vibration of reeds can be effected by the vibration experienced through the bag. In fact our entire instrument vibrates when we play.
The Reed Book DVD-Rom is the most advanced publication available today to demonstrate the methods used to obtain perfect strength and harmonic balance between your reeds. The Complete Pipers Handbook also explains these methods in detail. These two publications are available from the School of Piping Shop.
When we sell drone reeds at the School of Piping Shop we select them for balance between strength and also tone before dispatch. This will help greatly in set up.
While you are there you can download your free issue of the Gone Piping eMagazine.