What kind of box? What car?
ok so I know this is the wrong way to go about it... but let me take a guess. You don't have a standard trunk setup and you're getting slightly more cabin gain and you are tuned pretty close to your vehicle's resonant frequency so you get a slight bump there. The standard choices will be off here. There was really no way to code them in. To get closer try vented(odd order alignment) and "hatchback". I find that boxes tuned over 32 hz need the (odd order alignment) choice and anything but a standard near the rear of the trunk with the port facing backwards is not a sedan.
The effeciency rating on a sub is a calculated value that is only true at higher frequencies, they usually say 1k, but it's true a bit higher up depending on inductance a few other things. The rated effeciency on the woofer won't mean jack shit at 45hz where you burp at. BL will determine how far the woofer can move near tuning off a given amount of power and loading on the suspension. As someone else already said, I can find you a 6.5 that is over 100db/1w/1m effecient, bet you it won't meter anywhere near what your program will calculate because it's not that effecient down low. No offense, but it's much easier to simply download winisd or something like that and simply add some basic cabin gain to it.
Thanks for reinforcing that point for those reading this that might not have read where I said that. Want to join eCrack.net?
not sure i cant get them from the company yet i shot for an 85-87-90 its 18"+
port facing rear of car about 3 inches from the trunk opening. Subs facing the driver side. Its a normal ported box. But you do have one thing right, 44hz tuning but my car's resonance is 46hz.
A Denali is a SUV and in this case counts as a hatchback.
It will probably be close enough to give you a ballpark figure.
