ported or seal midbass box

i was wondering if i should seal or port my boxes for my midbass, which are 2 8" orion xtr dual 4ohm voice coils. each sub will be wired in parallel for a 2 ohm load powerd by a precision power a300 (75x2 4 ohm, 150x2 2ohm) in stereo. any suggestions?

 i got the subs really cheap, just thought i would use them as mid bass, rather than purchase new mids. i got 6.5 apline componets up front for mids and highs, was going to use the 8's for rear mids. and its my luck that these are not the MB's. too be honest im notsure what i think true mid bass means. can you clarify mid bass so i will have a better understanding of it ?

"Mid bass" is a term that describes the frequency band in the upper range of "bass" and the lower range of "midrange."  It is generally between around 100 to 300Hz.  In car audio, midbass refers to the band between the crossover frequency of the sub and of your mains.  So, if you have your sub crossed over at, say, 80Hz and your mains high-passed at, say, 180 Hz, the band between 80 and 180 will be a "hole" in the sound that your midbass can fill.

Take your Orion subs, wire than at 8 ohms in 0.5 cuft sealed enclosures, power them from your good stereo amp with a notch filter crossover set to between the setting you are using for your sub and for your mains.  It will dramaticlly improve your sound.  And if you can, install the woofers in kick panels in front.  If you can't do this and you put them in the rear, your soundstage shifted rearward a bit which might be OK depending on your taste.