I just got a 10" Infinity Kappa Sub and it calls for a 0.75cu ft box. My friend is willing to give me his Q-Logic Box, but it has a net volume of 1 cu ft. If I use this box, will the sub sound bad? What are the cons for going this route?

 

depends on what #'s you are looking at for the sub and box. Im sure that # for the sub is for a sealed box, which I think the Q logic box is, if they are both sealed, that will be perfectly fine. If you get too big, you will lose some of the tightness from the sub and it wont play as loud. But that little of a varience is ok.

 

those are guidlines you can go a little one way or the other however as ou sig said if it is a sealed box you will lose some of the tightness however your best bet would be to try it out

<---- not a huge fan of q logic boxes

 

You can try it out but IMO I would build my own box exact to spec. Sealed boxes are easy to build. Get yourself some 3/4 MDF, 1 1/4-1 5/8" screws(drywall is good) some wood glue or liquid nails, some caulk or silicone to seal it. I just built a vented box over the weekend. A little bit more challanging then a sealed because of the tuning and it's a lot bigger then most sealed. 4 cuft after all displacement. But it was easy and exact.

 

A little bit bigger box will reduce the output SPL of the sub that can be made up with watts. But the true benefit is the bigger box will make the sub play deeper in Hz.

The sub might need .75 cu but you also must factor in sub displacement within the box. Once you factor that in I would guess you might be about right.