So I have a box built quite a while ago for a 10" sub that expired many years ago. Turns out the box volume and external dimensions are perfect for a new project. Now, if I mount a 12" sub with the magnet out, does it matter that the hole in the box was cut out for a 10" speaker? As long as the surround doesn't hit the wood, should it really matter?

 

Most definetly. You are mounting the sub inverted and the specs stated for it are most likely for the sub being inside the box, not outside. It will work but it might sound crappy. If you invert and dont want to play around alot with boxes and ideas your best to seal the box and then run it inverted.

Also why not just cut the 10 inch opening to fit the 12?

 

With the sub inverted, the box volume is exactly where I want it. It's a sealed box already so no need to worry about sealing it. It's gonna run inverted regardless of what box is used 'cause I like the look of the motor structure! I can't cut the opening any larger or it will be larger than the front piece of wood, the outer edges will be into the top and bottom. I don't think it's good for the box integrity.

 

Oh sorry i misread and thought it was a ported box. If it sealed then sure, just make sure your cone or suroround does not hit the box and you should have no problems

 

Thanks bud, that's kinda what I figured. Just wanted confirmation.