Bandwith for different frequencies has to vary significantly.
65 Hz (63.5 Hz) and 8kHz should be extremely narrow.
Other bands can be (or better: must be !) much broader.
To make it nearly
perfect you have to do much trial and error to find the individual sweet spot of bandwith for every individual frequency band.
If 13 bands are too odd than 12 bands like this could be an alternative:
40 - 63.5 - 90 - 170 - 350 - 700 - 1.4K - 2.8K - 5.5K - 8K - 12K - 16K
or
40 - 63.5 - 90 - 170 - 350 - 700 - 1.4K - 2.8K - 5.5K - 8K - 11K - 15K
IMO 10K is definetly the Achilles' heel (weakest spot) like a lonely soldier in the middle of nowhere (5.5K....................................16K) with the order to take care of superior forces.