Sub box. Placed in cabinet

We are in the process of building built in cabinets and shelves around the fireplace where our tv is located.  Wife wants all the gear hidden and out of the way.  So my plan is to have 2 cabinets on the left side one will house the av gear and the second will hide the sub in my 5.1 setup.  The current plan is to build the cabinet with no bottom so the sub will rest on the floor like normal it will just be hidden away sort if speak.   Anyone see an issue with this idea?,  also the floor is hardwood if that makes a difference.

I have a small sub, 8 inch driver sealed box alignment, forward firing, placed in a cabinet in my secondary system.  I found it beneficial to provide a slot vent to the rear of the cabinet to even out the response.  It is placed on the cabinet, not on the floor.  I'm not sure how a larger sub with a different driver configuration would respond.  My guess is that a ported sub or downfiring sub would not fare well in that environment.