Quick Precision Speaker Port Question

Hi guys. Just a quick one.

I'm designing a two way bass reflex speaker. For the port, the tuning freq is 55hz, diameter 2 inches and winISD recommends a length of 6.40 inches.

When putting this into Precision port calculator, these are the results I get:
Is it literally just telling me to make the center tube 2.5 inches long and then stick the two flared ports on each end? 2.5 inches seemed small to me, but I guess if with the ports the overall length is 7.5 inches it wont matter? Also does it matter that precision is recommending 7.5inches overall length but winisd is 6.4, or is is so miniscule that it will be inaudible?

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