Sealed or ported?

I built an enclosure, pictured here.  For a week or so, as I was working on it, I was running it in the truck.  I had not sealed up the bottom, it was completely open during that time.  It sounded good.

I had intended to run the enclosure sealed, so this weekend I sealed it up.  When I got it back in the truck, well, it doesn't sound as good.

It's a 10" Rockford Fosgate, box is about a cubic foot, odd shaped.

Should it be ported?

It all depends....

What are the specs for the sub.  1cuft sound about right for a RF 10" sub, but read the spec sheet.

As soon as you seal a box it will require alot more power for it to really pound.  Maybe you dont have enough power. 

If you port the box you will prb need to make it bigger (usually 1.5-2.5 for a 10") again read specs.  Ported usually requires more air space. 

The space maybe too small (did you account for the displacement of the sub itself, a large maganet can displace alot of space.  Too small of a space can really decrease your sound and SPL level plus it aint too health for the sub.  U could try to fill it with ploy filler (fibreglass insulation or batting) This will 'increase' the amount of space your sub will 'see'  with this method you can "increase" your space up to 20%.

I would try this before i ported or build a new box.