Can somebody confirm this calculation?

[Eton]

I'm trying to determine the Square Port length

VB=50 Lt
FB=30Hz
Height= 1 inch
Width= 8 inches
Port length = 11.110 inches or 13.5672 inches
which is correct ???
Thanks

 

[kelticwizard]

According to WinISD, it is 10.10 inches.

However, also according to WinISD, the length of 13 inches will only lower tuning 3 Hz-down to 27 Hz. Which won't change much. So relax-you are in the ballpark.

 

[Eton]

Thanks.