You have two options to adjust:
– Identify the canes that have poor response sounding instrument and require adjustment before opening and adjust these reeds.
– With open instrument visually identify which of the rods have a larger opening at all and make these adjustments.
I recommend the first option.
Also remember that it must be a minimum opening in the reeds you are setting, if you close it too much will have a similar response when the cane is very open.
In the example image, the reeds that your settings should look like the smallest cane image.