I'm not sure how much personal experience or testing any of you have done without modeling it first....i gave up on box programs years ago.
I've learned that the programs that call for ports that are 'supposed' to be 40-50" long to tune it "low" are waaaaaaaaaaaaaaaaaaay off. Regardless of how 'reputable' the program is...
I've personally never had a port longer then 20" long...when i ran 150sq of port in the thunderbird and it'd do a 49.9 on the headrest at 29Hz....
Go figure, Experience and testing winning out on a program that is based solely off of numbers and scenarios...
I've said numerous times, open the port up. But yet you go right back to the computer program and say 'no thats not right'.
Numbers may not add up and graphs may not look correct. But if i recall isnt the whole idea of listening to music....is to listen with your ears, and not with your eyes?
Edit: I'm not doubting the skills or reputation of the installer one bit, but if the listener cant tell the difference between 250 watts a sub, and 600 watts a sub and it 'sounds the same'...it leads my mind to wonder.