I actually started off with no point and was as useless as a 3 dollar bill.. but since we are in the argument.. lets be clear on something.. Db/SPL levels is not everything.. we are talking about a daily here.. not an SPL build.. for one.. so in my 'subjective' listening.. loudness is not everything.. but rather to feel.. the bass.. in my chest actual down hard core solid tight deeeeeepppp bass and loudness..
In MY Truck.. with MY equipment sealed box spanks for SQ Daily every time.. for one.. the response curve is much different of course.. even with all things being *Perfect* the ported box only has a slight range slightly below and above the tuning freq. peeking out at the tuned freq. The sealed box has a more flat response curve having a wider response ability.
Now with that.. because the ported box will peek higher at a certain tuned freq than the sealed box.. comes the actual build of the box.. and its loading.. factoring in the natural fz of the truck. which can and does give me a slight additional db of loudness in the truck.
In addition.. the sub it self can take the power needed to reproduce the same note as the ported box can with less power.. as well as.. the sealed box has better control in the freq curve the ported can not once out side of that particular range around the tuned freq. where as the ported setup would tend to loose control past that point.
The sealed with its flatter responce and increased handling of the cone movement out side of that area.. can be played lower and harder than the ported.
All in all, my statements for MY setup, you take my subs with all things being equal except the box.. put it in a ported box and loose a great deal of commanding low end bass.. out side of the tuning freq. in order to be able to handle it you tune too low and really miss some of the upper range.. all in all we are talking a total loss of about 15~20 hz (number of total frequencies lost not the actual freq's them selves) with the ported box. So to achive the same output level and total fq. responce and commanding low end.. sealed is the better option giving an overall better SQ and Output..
I'm sure there will be more comments to come,. but I hope I made my self clear on what I'm trying to get at.. Everyone's results will vary.. me taking my setup into a different truck/care will yeild different actual results.. just as that perfectly tuned ported box would.. it may be perfect in design but practical output with all variations will differ..
You can design the box around the truck/car.. and I'm sure you might get a little bit more of peaking 'loudness' from the port... but at a loss of the above mentioned. But that's IMO based on my equipment tried and tested..
You can just as easily build around your vehicle with a ported setup, so I don't really see the point you're trying to make as being conclusive to sealed being > than ported for low end output.
db stands for Decibel which in an audio case is a means to measure SPL (Sound Pressure Level). Just because you can't hear those low frequencies doesn't mean it's not possible to measure them, they're still sound waves.
Never said that and completely agree and understand..
