hi all im after some help .. i want to build a slot box incorporating 3x12" 800w mt1207 mutant subs i know there not the best subs but its what i have for the moment total box size max tuned to 32/35hz if possible BASE=L,1270/W,510MM OR 50"/20" FRONT=L,1270/W,445 OR 50"/17,1/4" TOP=L,1270/W,370 OR 50/14,1/4" REAR ANGLE 71* REAR PEICE L,1270/W,455 OR 50"/18" this is the external size!!!! i work in mm normally but looking at forum i c you use inches i can increase the height by 50mm with a 50mm step in from a strut brace to the top rear of the box . im no good at math so calculating volume etc to get port length is beyond me USING 18MM MDF iv built a couple boxes before using the 12"/12" box for a 12" sub but i want to make this a slot box can any one shine any light my way used google sketch up to quickly show you what i want http://sketchup.google.com/3dwarehouse/details?mid=69c45bfee52d420b547c7b1f139b9019 i know it needs baffles and ignore the two cut outs on the top .i was thinking of making it with 5 subs originally but the other 2 i have aren't matching so three it is . like i say any help or if some one could assist using sketch up that would be so awesome .. and ill even tag ya name and post pics of it in action here for others to c how this forum is awesome !!!!!!