solobaric would be easy.. its a square hole.. mesure from the enge of the box... for the other cutout.. take a board meaure HALF the size you want the cutout and put 2 dots on a board at the HALF apart length... then put a nail threw one hole into the board u want the cutout...the other hole... a pen\nail watever u can use to scratch or leave a mark for u to cutout along... make sure you dont make the cutout 12" for a 12 tho lol
Say you need the cutout to be 11.1\4 inch for a 12.... space the nail and screw dot on the board HALF of that length apart... and the nail holds the board in the center of the cutout and twist the board around it marking your cutout line..
oo sooo i just put a hole anywhere in my homemadeprotracter thingy...then i measure from that hole to the utencil hole..so if im doing a 12 inch box..i measure half which is six inches between the two holes and for 15s i measure half which is 7.5 inches?
every subwoofer i have ever seen always has a bit smaller of a basket then the size of the cone area.. like my pair of dd9515s i ordered.. cutout says 14", you get what im saying? i would check with mounting secs on the manufacturor page to get what size u need but yes, u get the point. just make sure the nail is in the place u want the CENTER of the sub to be so it doesnt overlap the sides of the box or anything.
here u go