ported or sealed enclosure?

Ported will generally give you more boomy bass, typically in rap music but it does also depend on what sub you use as some subs are more suited to ported and others to sealed.  As a rule of thumb, take the Fs and divide by Qes, anything above 50 is more suited to ported, below 50 is sealed.  Again this is just a guideline.  Fs and Qes should be found with the instructions of the sub under the thiele small parameters.

For extended low frequencys (deeper bass) use a ported box, for a tighter, more accurate bass go with the sealed.  Whole books have been written on the subject so there is a lot more to it that you can go into if you want, try books like The loudspeaker design cookbook by Vance Dickason and others by David B Weems.

Wotugot4me...I have a Pioneer sub and I used the formula (F's divided by Qes) you presented to figure out what type of box (sealed or ported) my sub should be in.  The number I got was 77.1.  Currently, the sub is loaded in an enclosure of .81 cu. ft. and it hits low and hard.  Based on that formula...would the sub perform even better if it was ported?  The specs for the sub (TS-W2502SPL) call for a minimum volume of .95 cu. ft.  The sub is definitely an SPL sub, but it rocks in a sealed box.  Which, like you, I prefer a sealed box for it's tight controlled response and seamless adaptability to any music.

You can go on calculations and formulas as a starting point, but in the end...if you're not sure, build two test boxes (one sealed & one ported) and see which one you like more.  Yeah...it'll cost you a bit more money and some extra time, but the payoff is being completely satisfied with the performance of your sub(s).